Category Archives: Perennial plants

tree walk.

Last Monday, my dear friend and Community Forester, Chuck Sugent, and I took a neighborhood stroll to identify trees because I find myself recommending (or “oh, that’s an oh-no-no’ tree!”) at the farmer’s market; but when it comes down to it, I can hardly identify any trees at all and rely on the Front Range Tree Recommendation List. or the Denver approved tree list. My learning style is not entirely visual but seeing and discussing something certainly increases the likelihood of future accurate recitation. After a minor location miscommunication (“Heading your way!” “Good thing you sent that. I thought I was heading your way. Oy!”), we set off through a tree-lined neighborhood between downtown and City Park.

Chuck is the kinda guy who’s gonna be the good guy: he’s got the information, and he wants to share it (perhaps with an old-timey gangster of New York wiseguy affectation). So he took no pause when I suggested the idea of a tree walk. We’ve talked about the CMG program and community forestry in terms of our own participation for community stewardship, and have oft discussed a crossover—and thus, we went! We set off to name the trees and, in addition, ended up pretend-pruning, dreaming, and trouble-shooting all the ailments. Everything I espouse, I learned from Chuck (it was a very informative afternoon). Here’s an absurdly simplistic overview of the main players:

Crabapples

Gorgeous and quite popular. Responsible for the pinkening of the city each spring. Many varieties of different sizes and fruits. Also, edible. I grew up with a crabapple tree at my grandmother’s house which was the source of many summers dares to the youngest of us to “just try it! You’ll love it!” followed by giggle fits at the sight of desperate acceptance puckering away at the tiny bite. So—raw is a no, but cooked with sugar and acid makes for delicious desserts; or my family fav: Crabapple whiskey. Fill a jar with crabapples, a cinnamon stick, ginger, cloves and top with whiskey. Tuck it away until Christmas, strain and serve.

Silver Maple

Thirsty mother lovers. They grow quickly and provide lots of shade. We have a ton of them in our metro canopy, but they are currently on a moratorium from planting in city right-of-way areas.

Honeylocust/Black Locust

Black Locust has a darker trunk than the Honeylocust. Tiny leaves, gorgeous lemon color through the fall. However, tiny leaves make a mega mess–however, however, the leaves decompose quickly and return the nutrients to the soil. Also, a popular choice in this area, and continues to be on recommended tree lists for a new planting (NOTE: many varieties are on the recommended list, but the Sunburst Honeylocust is also on the moratorium list for street planting in Denver)

Sugar Maple

Classic Canadian flag. Gorgeous flaming fall coloring. The moisture level is moderate for this group, and they do not tolerate salty soil very well but are fairly drought tolerant. 

Hackberry

This one makes Chuck’s shortlist of recommended trees for the metro area. The Hackberry has no known local pest, is native to Colorado, and drought tolerant. The Hackberry can get up to 50 feet tall, so consider this one for a street-side as a shade option. Lovely red berries darken to maroon in the Fall and provide home and a food source to the critters. Chuck calls this one a Hammer Tree; an all-around good selection.

Linden

When we happened upon our first Linden of the walk, Chuck took a step aside and said, “There are two kinds of Linden trees, and here’s how I remember them: LLL.” At this point, he raises his voice to denote the first type “LARGE LEAF LINDEN” followed by a substantially lower volume for the “littleleaf Linden.” He proceeded to crack himself up, and we carried on. There are many cultivars of Linden recommended in this area. Lindens are an attractive pyramidal shape, sensitive to salty soils, and their flowers attract bees and birds. Beware of the area you are considering, Lindens do not love high heat areas and should be planted away from any hardscaping. 

Oak

Ever sturdy and reliable. The oak leaves have a bit of a leathery texture to reduce evapotranspiration, making them more drought-tolerant, and an excellent tree choice for this area. Their leaves differ in pattern depending on the cultivar but typically have the characteristic lobes and sinuses. The Bur Oak (recommended for the Metro area), is roughly obovate with many lobes and is pale and fuzzy underneath.

Ash

If you’re reading this… need I say more? See Plum for contingency planning. We have a million (estimated 1.45 million in the Denver Metro area) Ash trees. Aside from the EAB creeping into town, the Ash tree has a tendency to appear real leggy under the canopy when not properly pruned. We saw many examples of Ash trees with a lot of deadwood inside the canopy; this can be problematic when the wind picks up. They served a great function for our canopy by growing quickly and providing robust shade; but unfortunately, we’ve got to continue considering the impending Armageddon. What build projects shall we consider for a future influx of Ashwood? Denver also has a moratorium on planting Ash trees in public right-of-ways. 

Plum

The purple leaf plum is my fan fav, and will likely be planted in my own front yard next Spring since my future self called and said: “This giant elm thing in your front yard was planted improperly, is massive, and when it goes, your front yard is gonna be U.G.L.Y.” Contingency planning in full swing. I encourage y’all to take a walkabout your own homes and chat with future self, especially regarding anything that is shade bearing. Something I picked up from my buddy whilst traipsing on the tree walk: purple leaf plums require regular pruning for flowering (Is anyone else as smitten by the plurality of prunes in this context?)  Remove the deadwood and prune 1/3 the length of new growth. We found a perfect example and made pernicious prunes with finger scissors.

Colorado Blue Spruce

Beautiful. Also better at a higher elevation. We did see a few stunners, though, and learned a neat trick for tree ID: the leaf of a fir tree will be flat and flexible. Spruce, on the other hand, will be square and sharp (see what he did there?). Grab a leaf, roll it between your fingers, and name it quickly with this handy guide.

Photo by Dids from Pexels

Aspen

May make it to a mature size but inevitably will crash and burn. I’ve been touting this gospel for a while now, and take every opportunity to point out a struggler to my wife. which has become problematic, because now she counters by showing me all the healthy Aspen in the Metro area. The truth of the matter is an aspen tree (or maybe even a small clump of them) has the ability to thrive with the proper tender loving care… for a while. Above and beyond the statistically insignificant number of Aspen in the front range who appear to be doing well, they aren’t built for this elevation, and forcing them to do so causes undue stress, and makes them more vulnerable, hastening their predisposition to die anyway. Don’t do it. Go to the mountains more often and enjoy them in their own territory.


Beyond my self-imposed (and singularly played) trivia that entailed me interrupting, pointing, and shouting guesses; we also discussed the conversational piece of tree maintenance. Chuck indicated he has many chats with his neighbors about their trees and takes these moments to build his community and integrate his passion with friendly educational moments. We discussed the evidentiary tribulations of a tree in demise, that twists it’s trunk and bears the stripes of turmoil. We debated the suckers: their yappy attempts to address internal stress, and what to do with them (should we leave them and let it try to capture the energy it is craving? OR whack them back always? And when?) We talked about injury to a tree, and how the tree may cover and scab the wound, but the wound remains and the tree is still vulnerable. Chuck showed me a hackberry tree covered in galls. We both got lost in our attempts to recall the origins but settled on something about defense mechanisms and how they rarely hurt the tree.

As we were nearing our last corner on the way home, Chuck remembered a tree we hadn’t encountered that he loves. I’ve developed a habit this summer that whenever I see this tree, I shout it’s name, probably because it’s so fun to say, but shouting also seems appropriate just to communicate the whimsy of the CATALPA! Just try and say it without a bit of a shout. The Catalpa is also a recommended and robust tree for our area. It’s got those built-in wands and/or swords for play, and bright green wide leaves provide a huge amount of shade. . They are another tough tree, worthy of your scape.

Other items on Chuck’s “Oh no-no” list? Planting a tree too deep? Oh, no-no. Scoffing at the bare root and opting for a burlapped and caged tree? Oh, no-no. Planting anything from the Birch fam in Denver? Oh no-no.  Hiring an arborist annually to tame your trees? Oh, no-no. With a little reading, Youtube-ing, or friendly forester finding, folks can save bunches of bucks by learning how to make the minor pruning adjustments to your tree every year to avoid the future big bills from an arborist. Trees can easily be grown and cared for by their owners working from reliable and factual info. Of course, always consult a pro when your tree questions start toeing the line safe vs. unsafe. 

https://extension.colostate.edu/topic-areas/yard-garden/#trees

As DMG’s we get loads of questions about trees at the farmer’s markets. We try our best to offer small sagelings of fact-checked info, but what I’ve found to be more helpful is keeping the company of a forester. Trees are just as essential to the garden crew as our lawns, beds, and weeds. I encourage everyone to branch out (a thousand apologies for that one) and get connected–or get involved and become a Community Forester, yourself!


PS. Did you know if you live in Denver you can get nearly *free* trees?

By McKenna Hynes

Apprentice Colorado Master Gardener since January 2019

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The Leafcutter Bee in Action

Rose leaves with leafcutter bee damage

Leafcutter bee damage to leaves is cosmetic and won’t harm the plant.

Have you noticed any circles missing from the edges of your rose leaves? Do some leaves look like little violins?

If you answer yes to those questions, congratulations! Leafcutter bees have taken a fancy to your garden.

Leafcutter bees are native bees and important pollinators for our native plants. These bees are a bit larger than a honeybee and are dark gray with hairy white bands.

Female leafcutter bees cut circular snippets from rose leaves to create wrappers to line brood cells for their young. Think of these rose snippets as blankets for baby bees.

It can take as little as 10 seconds for a leafcutter bee to use her mandibles (jaws) to cut a snippet and fly off to her nesting site. Check for yourself on my short film called The Leafcutter Bee I posted to YouTube.

After seeing the speed at which she can land, snip and fly away it’s no wonder leafcutter bees are included under the family Megachilidae which means “big-lipped.”

pink roses

The Canadian Explorer ‘John Cabot’ climbing rose is a favorite of leafcutter bees.

It’s not easy to catch these bees in action  because they’re so speedy. However, earlier this season I staked out a spot near their favorite climbing rose and patiently waited with camera in hand. Finally one bee flew in and tried landing on a leaf or two before finding the perfect one.

After cutting the leaf, she flew off to her nesting site. The site could be in holes found in a piece of old wood, stems of plants with pithy centers or anything with a hollow center. One year I found leaf snippets stuffed in a piece of unused garden hose.

These pieces of leaves are the construction materials for brood cells that are packed with pollen to feed the young. In CSU Extension Fact Sheet 5.576 on Leafcutter Bees, Dr. Whitney Cranshaw explains that leafcutter bees are solitary bees and don’t produce colonies like honeybees.

Instead, leafcutter bees construct “nest tunnels that may contain a dozen or more cells forming a tube 4 to 8 inches long. The young bees develop and will remain in the cells, emerging next season.”

Every summer I watch for evidence that leafcutter bees have been busy in my garden. As soon as I see rose leaves that start to look like Swiss cheese, I know leafcutter bees are happily at work.

Text and images by Jodi Torpey
Denver Master Gardener since 2005

A Denverite Visits New Orleans in July, Leaves in Awe That Anything Grows in Colorado, Like, Ever.

Image by McKenna Hynes

I recently returned from a little summer vaca in the South. New Orleans in July (a questionably timed vacation, albeit) is showy and fragrant; the ferns suckle lovingly to any crack and crevice providing green brush-strokes and blots everywhere, palms fill beds and pots alike, all of my houseplants are thriving in the wide open, the sun is scorching, and as our pilot reminded us as we prepared to de-plane, its humid enough to confuse a frog. I was constantly amazed at how effortlessly everything seemed to grow.

While in New Orleans, I was frequently amused by how the rest of the country (mis)understands Colorado living conditions. For the most part, folks think we spend most of the year dreaming of gardens as we stare out our frosty windows waiting for the snow to melt, visiting floral places abroad, and wearing multiple layers of socks at all times. Soooo… basically gardening at 10,000+ feet? While these perceptions are laughable, I started thinking that even though we don’t live in perpetual wintry wonder, the challenges we face to make anything grow aren’t necessarily less surmountable than our fam in the lofty-actual-mountains.

We were welcomed back to Denver with a remarkable storm featuring lightning, torrential rains, booming thunder… and hail. Of course, the very next day was smokin’ hot with nary a whisper of the siege.  Maintaining a vibrant garden in the Front Range is an extreme sport with our baffling daily fluctuations; the entire notion of keeping anything alive here seems impossible at times, but we’ve gotten pretty good at strategizing. Here are a few resources I’ve tracked down this year to help us all maintain beauty, build our skills, and be stewards to our land and community.

Image by McKenna Hynes

Resource Central is a nonprofit organization based in Boulder that helps communities conserve resources and build sustainability efforts simply and cost-effectively. Their water-saving initiatives include native plant sales with simple designs for home gardens and often include low water perennials. They also have a tool library in Boulder where you can borrow for a couple of bucks per day so you don’t just buy the tamper, hedge trimmer, turf roller, or post hole diggers you need so infrequently. 

The cities of Boulder, Lafayette, and Louisville partnered with Resource Central to give customers a Garden In A Box for turf-removal. Their Grass to Garden initiative is available to all communities with tips and resources to convert high water-consuming turf to low water garden areas. For the North Metro area, they have resources for assistance removing and disposing of turf, landscape architect recommendations, and more.


Denver Water coined one of our most successful water-wise strategies with xeriscaping. And to keep sharing the good water word, Denver Water also partnered with local landscape architects to provide us mere civilians with some FREE! FREE! FREE! creativity. For those of us who are new (it’s me) who struggle with vision (all me), and are easily overwhelmed by the thought of starting fresh with a blank canvas (still, totally, all me), they’ve curated a bunch of plans for a variety of situations. They have plans for sloped xeriscaping, budget-friendly xeriscaping, narrow bed xeriscaping, year-round beauty designs, and many more. July is also Smart Irrigation Month! Head to Denver Water for tips on maintaining irrigation systems, watering rules, and efficiency strategies.

And for the grand finale top-notch gardening game-changer, check out Plant Select for all your future dreaming. Plant Select is a nonprofit partnership between Colorado State University, Denver Botanic Gardens, and professional horticulturists to identify smart plant choices for the Rocky Mountian Region. Their mobile-friendly site has a tool to help you find plants that will suit the conditions you’re facing. I tend to challenge the tool to see how obscure or specific I can get, and it always provides me with something unique and gorgeous. Plant Select: taking “right plant right place” to an accessible and fun platform. Say So Long! to the multiple Google tabs researching the same plant with contradicting information on each site; Goodbye! Big Box Store swindlers promising “You REALLY can’t kill this one!” and go get yourself some good, wholesome, ACCURATE information quickly and easily from Plant Select. They also feature some garden designs and ideas.

By McKenna Hynes

Apprentice Colorado Master Gardener since January 2019

Reimagining a Denver Hell Strip

 

A typical hell strip in “Any Town USA”

The hell strip (more politely called a tree lawn) is that pesky rectangular area between the street and the sidewalk. It’s a challenging spot – surrounded by concrete surfaces which make it super hot in the summer and subject to harsh elements in the winter.  Apprentice Denver County Master Gardeners (CMG’s) Elizabeth and Daniel Neufeld challenged themselves to redesign their hell strip by working with, not against the conditions at hand. Their new strip garden incorporates xeric native plants in a creative design which complements their early 1900’s Mayfair bungalow. Here’s a step-by-step description of the project in Elizabeth’s own words.

Site Description and Preparation
The 8.5’ by 16’ site had been a weedy portion of our hell strip. This section of our lawn was never irrigated and though we used a manual sprinkler on it for years, it never really thrived. Weeds from an adjacent bed also crept in and began to take over our lawn.

In June 2017 – after talking to CMG’s at East High’s Farmers Market – we put down 5 mil black plastic over the entire area to solarize the soil and kill the weeds. In March of this year, we removed the plastic and started to work on the soil.

The top several inches of soil was relatively good. Below that, though, was hard packed clay. Based upon our classwork to become CMG’s, and discussions with other CMG’s, we knew that we wanted to create a Native, drought resistant, garden. In order to have the appropriate depth of 2”-3” of pea gravel on top, we needed to dig out the clay. MUCH harder than we anticipated.

First I took every trash can we owned (about 5), and another 3 from a neighbor, and filled them up with just the first 4-5 inches of the topsoil. Then what to do with the clay below?  You can’t put it into the regular trash bins, nor into the city’s green compost bins as  they do not accept soil, primarily because of its weight. I secretly thought I could add just small amounts of dirt weekly and they wouldn’t know the difference. Yet this wasn’t right, and would take forever. We went online and called several places about renting a dumpster, yet the smallest dumpster we could find was going to cost $500, and we’d need to get a permit from the city to place it on the street. We needed another plan.

Perhaps you’ve seen smaller, heavy plastic canvas bags in people’s front yards as they do small remodeling jobs on their homes. These “bagsters” can be bought at a big-box store, and they hold up to 3300 pounds. Once filled, Waste Management will come and collect them for a fee. So we purchased one of these, set it up on our sidewalk next to the hell strip, and completely filled it with about 4” of the clay subsoil. It was truly a Herculean task, and it weighed over a ton, literally.

After the Waste Management dump truck removed the bagster and all its contents, we then put back all of the topsoil we had previously removed. Another day of heavy lifting.

Plant Selection
What to choose, what to choose?! Thank goodness for the CSU Extension fact sheets on Xeriscaping, Low Water gardening, and Native Plants. We also had Pretty Tough Plants, a book by the experts at Plant Select. We  spent a fair amount of time at the Jefferson County Extension office xeric garden, and the Denver Botanic Gardens, and took pictures of plants we liked. We spent a huge amount of time debating which and how many plants to include. The mix and quantities of plants we decided on follow. Click images for plant names.

  • Berlandia lyrate,“Chocolate Flower” (4)
  • Agastache, “Sonoran” (2) and “Coronado” hyssop (1)
  • Delosperma, “Firespinner” and “Red Mountain Flame” iceplants (4)
  • Eriogonum umbellatum, “Kannah Creek” buckwheat (2)
  • Schizachyrium scoparian, “Little Bluestem” (3)
  • Tanacetum densum, “Partridge Feather”  (3)
  • Prunus bessyi, “Pawnee Buttes” Sand Cherry (3)
  • Amorpha fructosa, False Indigo Lead Plant (1)  not shown
  • Miscanthus sinesis  (1) not shown

Design

design
In talking with a fellow CMG apprentice, Brenda Reum – who has her own landscape firm – we decided to put a false arroyo diagonally through the rectangular site. We also wanted a few larger accent rocks, and some medium size rock around the edges. We went to a local sand and gravel company and selected some larger rocks, and got several 5-gallon buckets of mid-size rock. During this time period (late April/early May), we also went camping in Western Colorado for a week. While driving on a dirt road along the Delores River, we came upon a pile of rocks – and collected a few dozen we liked and brought them home!

After creating an outline of the arrangement of the arroyo and the planting on paper, we commenced planting. Like many a good idea, the execution was more time-consuming than anticipated.

Once the planting was complete, we used an online calculator to estimate the amount of pea gravel needed. To have 3” of pea gravel on the site as large as ours, we would need 1 ton of rock. We put a large tarp on the street adjacent to the garden and the delivery truck dumped it on top. We spent hours shoveling the gravel over the dirt, then carefully placed our ‘trophy’ rocks through the arroyo and around the edges. Some clusters of rock are near some of the plants, and we placed a piece of weathered cedar (also found during the camping trip) and a piece of ‘rust art’ in the bed.

Now
20180622_173305The bed has been in for about 6 weeks, and it’s looking great and seems to be happy. We initially watered the plants every 2-3 days for the first 3 weeks, and have now cut back to once weekly. The ice plants and partridge feather are already spreading out, the chocolate flower and hyssop have been blooming. The little bluestem has yet to fully take off, but those plants were the smallest of all when we purchased them. We left plenty of space for the eventual growth and spreading of these plants, and look forward to their ultimate size and height.

Time and Cost of Materials
It is hard to calculate the total amount of time we spent — yet it was easily 3 times more than we thought it was going to be. It was approximately 100 – 150 hours of our own labor.

We found the plants at several independent garden centers as the big box centers did not have any of these. And because of this, the cost was more than we had anticipated, too. We spent approximately $400-$450 on 23 plants.

We spent $30 on purchasing the ‘bagster’, and $120 to have it carted away. We spent $85 on the pea gravel (including delivery), and another $40 on the larger rocks we purchased. All totaled, we spent $675-$725 on the new Native garden.  We are so pleased with the results and hope to expand our collection of native plants in other parts of our garden.

Thank you, Elizabeth, for sharing your experience! If you have a question or comment for Elizabeth, she’ll respond in the comment section.

Photo Credits: Plants: Plant Select.org,  Street Image: Bing Free Images, Garden diagram and completed garden: Elizabeth Neufeld

Posted by Elizabeth Neufeld and Linda McDonnell

 

 

Japanese Beetles Make Their 2018 Debut

 

jb_1

The Japanese Beetle – pretty to look at but oh so destructive!

June is a glorious month in the garden, but it also the cue for adult Japanese beetles (Popillia japonica) to emerge from the soil. They’ll hit their peak from late June through at least August. I haven’t spotted the metallic green and copper devils in my garden yet, but if the past is any indication, they’ll visit soon.

Colorado State University offers this comprehensive fact sheet with everything we need to know to defend our plants. It’s an especially valuable reference when considering products which may or may not be beneficial in reducing the pests while doing minimal damage to the ecosystem. If there were best seller lists for gardener information, this would be on the top!

Here are important takeaways from the fact sheet:

05601-fig5Japanese beetles feast on foliage, buds and flowers of their favorite plants. Particularly susceptible are roses, Virginia creeper, Linden trees, Rose of Sharon, Japanese maples, Silver lace vine and Gaura are among their favorite targets. Tell-tale signs of Japanese beetle damage are a skeletonized pattern of mutilation on tender, new foliage and deformed flowers or buds. While unsightly, the damage will not kill the plant.

05601-fig8Traps are not beneficial. That yellow trap you’re tempted to hang in your yard is an open invitation for more Japanese beetles to visit. The trap won’t be able to catch them all and the effect is more, not less damage. Perhaps if your neighbor hangs one…?

Picking does help. Japanese beetles are easy to spot in the cooler parts of the day and can be coaxed into a jar of soapy water with a twig or a shake. Catching is preferable to squishing, as a squashed beetle releases a compound which lures more of their kind. While it may not be fun, catching is oddly satisfying!

Do insecticides work? As always, caution must be used to avoid damage to pollinators, especially when plants are in flower. Products containing pyrethrins, azadirachtin and acetamiprid – used in the early morning or at dusk – when bees and other pollinators are less active – are the safest. See the fact sheet for more details and follow all product recommendations carefully.

Consider removing temptation. Can you replace your Virginia creeper with something less enticing? Do you have roses that have struggled for years? Perhaps it’s time to replace with something less alluring. Conversely, when adding to your landscape avoid plants which are irresistible to this insect.

Late season turf damage. Each female Japanese beetle lays 40-60 eggs in her 4-8 week life span. Eggs are laid deep in moist turf soil. Since eggs and subsequent larvae thrive on moisture, keeping soil on the dry side will inhibit grub development and decrease turf damage. Grubs also munch on turf roots, so mowing at a higher height, which promotes vigorous roots, can help reduce turf damage.  More control ideas can be found in this fact sheet.

Have you spotted Japanese beetles in your garden yet?

 

Submitted by Linda McDonnell, a Denver County Master Gardener

 

Gallery

2018 Plant Sale Shined Despite Bad Weather

This gallery contains 7 photos.

Stormy weather failed to dampen the spirits of gardeners at the 13th annual Denver Master Gardener plant sale.  In spite of cloudy skies and cool temperatures, the cash registers recorded around 4000 transactions! “We definitely had our best sale ever,” … Continue reading

Pretty Tough Plants Book Review

I love the name of the new book by the experts at Plant Select. Pretty Tough Plants describes the family of Plant Select plants perfectly.

If you’ve grown any of these beautiful plants that are so well-suited to our gardens, then you know what I mean. If you haven’t grown any Plant Select recommendations, what’s stopping you? These are the plants that can help you be a more successful gardener.

Plant Select calls itself “a nonprofit collaboration of Colorado State University, Denver Botanic Gardens, and professional horticulturists.” I call it one of the best plant testing and introduction programs in the country.

Pretty Tough Plants: 135 Resilient, Water-Smart Choices for a Beautiful Garden (Timber Press, 2017) is a follow-up to Durable Plants for the Garden: A Plant Select Guide published in 2009.

This new edition seems to be more user friendly, both by its manageable size and in the plant presentations. Plants are divided into groups that include tender perennials and annuals, petites, groundcovers, perennials, grasses, vines, shrubs, and trees and conifers.

Each Plant Select description includes its scientific name, common name, mature size, flower type, bloom time, and best features. Understandable icons give details on sun and water requirements, as well as if the plant attracts pollinators or if deer resist browsing it.

The “Landscape Use” information is meant for gardeners who have difficulty matching plants to place or are unsure of how to combine plants for the most striking effect. The descriptions make suggestions for perfect placement and the best Plant Select companions.

Many of the gorgeous, full-color images show both a close-up view of the plant and a shot of how it looks in the landscape when in full bloom. One of my favorites is Redleaf rose (Rosa glauca) shown as a fabulous specimen plant, and closeups of the star-like single pink flowers and brilliant red hips.

An especially nice feature for this volume is the Plant Reference Guide in the back of the book. This guide provides a quick resource for matching the right Plant Select plant to the right spot in the landscape.

Besides the typical categories, there are two additional and interesting categories: Special landscape use and North American roots. Not every plant has a special landscape use, but when a plant is recommended for “dry shade, cold hardy,” like Denver Gold columbine (Aquilegia chrysantha), gardeners can trust the endorsement.

Prairie Jewel penstemon (Penstemon grandiflorus) is one Pretty Tough Plant in my xeriscape.

I’ve grown many different Plant Select recommendations in my perennial beds, and I can vouch for their resilience – one of the seven qualities a plant has to have to be added to the program.

In addition to being able to stand up to a challenging climate, Plant Select plants have to thrive in a variety of conditions, be water smart, have that “it” factor, resist insect pests and plant diseases, offer long-lasting beauty, and aren’t invasive.

I can tell Pretty Tough Plants was a labor of love by a group of passionate plant people. The photo credits read like a list of area Who’s Who, from well-known horticulturists to CSU Extension Master Gardeners. Pat Hayward and David Winger had the happy task of sorting and selecting images, including many of their own.

By Jodi Torpey
A Denver Master Gardener
(Timber Press provided a complimentary copy of Pretty Tough Plants for this review.)

Never Put a $10 Plant in a 10¢ Hole and Other Gardening Tips From Denver Master Gardeners

planting-1898946_1920Passionate gardeners love to talk about gardening, so with that in mind, we recently asked Denver Master Gardeners for their best gardening advice. Responses included tried-and-true practices, creative suggestions and good reminders for all of us as the gardening season kicks into full gear.

As the title of this post implies, we believe that great plants come from appropriate soil preparation. Amending with compost is often imperative as soil in our region tends to lack organic matter. But proceed with caution, as some plants, such as natives, prefer a leaner, less fertile soil. Too rich soil will cause these plants to underperform and often just flop over. It pays to do a little homework before planting, read seed package directions and have your soil tested.

One of our gardeners shared her recipe for amending soil: Add 1/2 a handful of both Alaskan fish pellets and triple super phosphate to half a bucket (such as a kitty litter pail) full of compost. Mix this into the planting hole for strong root development and beautiful blossoms.

A tip borrowed from the Rock Garden Society is to plant bare root. By gently shaking off most or all of the soil that the plant is purchased in, the plant will adjust to the garden soil without the soil interface (or boundary) that can occur between two soil types. Bare root planting promotes healthy root development.

mulch-1100555_1920Mulch, mulch, mulch is the mantra of many of our survey respondents as it keeps weeds out and moisture in. Add it like crazy each time you dig in the veggie, perennial and annual gardens and don’t forget container plants too. Small to medium-sized bark chips are popular, practical and pleasing to the eye. Natural mulch options are very effective, including not quite finished compost from the compost bin which will add carbon, feed living organisms, prevent water runoff and prevent compaction. Local arborists are often willing to drop off wood chips which would otherwise fill up the landfill. In the fall, mow over your leaves and spread them throughout the yard, they’ll breakdown by spring and add organic matter to your soil. Consider purchasing a chipper to grind up branches and other garden waste.

garden-hose-413684_1920Suggestions for responsible use of water include watering when the plant needs it instead of on a set schedule. Soaker hoses, often made from recycled material, are effective for watering plants at the soil line. Plants (even xeric ones)  need moisture to maintain healthy roots and overall strength, but often less than we think. For example, the Water Smart Garden at the Denver Botanic Gardens is watered about seven times during the season.

Weeding can feel like a no-win battle, but attacking weeds after a soaking rain makes the task easier. Pull weeds and unwanted volunteer shrub and tree seedlings when they are small, before they take hold in the ground or develop seed. Add stepping stones to the garden to avoid stomping on plants and compacting soil when working in the garden.

bindweed-1207738_1920A clever tip to eliminate stubborn weeds, such as the nasty bindweed shown here, is to take a large piece of heavy cardboard, make a cut from the edge to the center. Keep the cardboard as level as possible, slip the vine in the center and spray the vine with the herbicide of your choice or horticultural vinegar, which is sold in garden centers. The cardboard will protect surrounding plants from overspray. Aggressive weeds may require multiple treatments during the season.

One of our members recommends a tomato planting technique passed on through generations of farmers. She adds blackened banana peel to the soil and feeds them with skim milk upon planting and again one month after that. This less conventional practice yields her sweet, abundant fruit. While CSU can’t vouch for the scientific efficacy of this, the banana could be adding potassium and the addition of calcium may reduce the chances of blossom end rot.

plant-1585251_1920Growing tomatoes in containers is recommended for those with limited space. Select varieties which produce smaller fruit such as Patio, Cherry or Sungold. Use a large container (18+ inches in diameter), a sturdy support and a tray with casters. This allows plants to be moved from the path of hail or to optimal conditions. Container plants of all kinds benefit from weekly feeding of 1/2 strength fertilizer.

To keep pests at bay, try a thorough weekly spray of water during the growing season, including the walls of the house and fence. It’s a kinder way to shoo pests away.

If your vines need a sturdier trellis consider building one out of remesh, which can be found at hardware stores. It makes a durable, cost-effective support and can easily be cut with bolt cutters. It also can be attached to supports to create a dog run or create plant cages.

botanical-garden-413489_1920In the flower garden, invest in perennials for texture and dimension and add annuals for bold color. “Enjoy the randomness of some plants that choose their own spots to thrive” suggests one gardener. What a positive way to think of the seedlings that sprout up at this time of the year. Remember, too, that perennials may not come into their glory until the second growing season.

Gardening is a four season hobby. Winter watering of trees and shrubs will help keep them healthy and  veggie gardeners can get a jump on the season by using a cold frame or floating row cover to get an early start on lettuce, spinach and other cool season crops. Fall is a fantastic time to fertilize, aerate and over-seed the lawn. It is also an ideal season to divide perennials so that they settle in and are ready to take off in the spring.  Share your divisions with your neighbors, too, or trade for plants you’ve admired (envied?) in their yards. If you need more gardening space, solarizing or sheet composting is an excellent technique to ready a new garden bed and can be started throughout the year.

And lastly, a veteran gardener advises us to “Remember each little garden flower or planting arrangement is a moment in time. It will change. Don’t worry about it or take it too seriously.”

 

Written by Linda McDonnell with thanks to the many Denver Master Gardeners who shared their advice.

All photos courtesy of http://www.pixabay.com, a source of royalty free images.

It’s Winter and, Yet, I Dream of Cactuses

It’s January.  As I write, it’s cold.  It’s snowing.  The garden is frozen solid.  There isn’t much that can be done out in the garden.  But indoors, we can do a lot of thinking about and planning for about our gardens.  For me, this also includes thinking back to what has already been achieved. My special joy has been planning, making and planting my “desert garden”.

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Prickly pear peeks out of the snow

Having gained my gardening skills and horticultural knowledge in the temperate south of England, I was excited on moving to Colorado to try my hand at growing these interesting, drought tolerant plants.  Cactuses in England are generally small prickly jobs which sulk year-round in dry pots on the windowsill, gathering cobwebs.  I knew virtually nothing about them when I came to live in the USA.  My husband wasn’t much better; he told me he knew his cactuses had been over-watered when he saw mushrooms growing in their pots!

Call it what you will – rock garden, trough garden, crevice garden, desert garden. From big deserts to tiny tufa troughs, cactuses and succulents can be grown and enjoyed in many situations.  I know it’s the middle of winter right now, but I’m thinking of the sunny joy of seeing the Community Heroes Crevice Garden in Arvada and the new steppe gardens at Denver Botanic Gardens in the summer of 2016.  These showed me what could be achieved.  And as I gaze at the tips of Opuntia (prickly pear and cholla) plants poking through the snow in my front yard today, I am in awe at the extremes these amazing plants can tolerate.

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Opuntia x pinkavae

 

 

Our front yard faces north, not auspicious for cactus growing, but safely out of bounds to the dog and small grandchildren, and raised up above the sidewalk, so safely out of reach of passers-by.  The area I designated to be the “desert garden” is about 20 x 10 feet, bisected by the path from the sidewalk to the front door.  Despite its northerly aspect, this area does get a lot of sunshine from spring to fall.  A minimum of six to eight hours of direct sunlight daily is recommended for cactuses.  When we moved in, this part of the garden was just a boring flat patch of clay soil with rather elderly wood mulch strewn over it.  Again, not exactly the well-drained, lean (in terms of nutrients) soil usually associated with cactuses.  But I like a challenge!

To get things started, I raked off the wood mulch and underlying landscape fabric to reveal a flat, compacted, grey soil surface covered in the wriggling, white stems of bindweed like ghostly spaghetti.  I pulled as much of the bindweed as possible. Then to create some height and slopes I dug and shaped the soil into small hills sloping down towards the sidewalk.  We inherited hundreds of large granite boulders with the back yard, so my son and husband hauled a couple of dozen out to the front for me.  I chose the most attractive boulders and made sure they were of similar or complementary colors.  These were placed on the slopes, either singly as “specimen boulders” or in groups forming little “canyons” in which I could plant.

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Rocks, soil, river rock and neighbor’s turf

The slopes help to ensure rain (when we get it) runs off quickly so the plants don’t sit in puddles.  Pockets of water are trapped by the boulders giving little damp areas against the boulders and allowing water to slowly trickle down into the soil below.  To improve the soil drainage further, I dug in a couple of trailers’ worth of “squeegee” to a depth of approx. six to eight inches.  This is the name around here (I gather) for crushed gravel.  It is pinkish in tone and halfway between pea gravel and sand in size. Areas of small river rock (obtained for free from a neighboring garden which was being “re-done” – I love a freebie!) were laid as a transition from the “desert” to the greener area of the yard and the sidewalk.  After planting, a thick layer of pure squeegee was used as a mulch over the whole area.  This has been very effective at keeping the bindweed at bay, helped by merciless hand pulling of any little shoots that do make it to the surface.

The choosing of plants followed considerable book research, web browsing and advice from local nurserymen.  I used a mix of cactuses, succulents, grasses, small drought-tolerant perennials and bulbs.  Naturally, none of these are hot-house types.  They are all cold hardy down to at least Zone 4.  For many of them their natural environment is arid mountain-sides in Arizona and New Mexico where they bake in the summer and freeze in the winter. A couple of dwarf pines provide year-round green and structure.  (I had to remind myself that these two needed regular watering, unlike the rest of the desert garden, as they are young trees, albeit small.)

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Pinus mugo var. pumilio

Planting took place in June 2015, so these plants are now “enjoying” their second winter in our garden.  They spent two and a half months under snow in winter 2015/6 and came up smiling in spring 2016.  There were just two losses, both small Yuccas which had rotted at the crown.  Fortunately, I had extras safely potted up behind the house, so they were immediately replaced.

For the first summer, I watered maybe twice a week, using the mist spray on the hose head.  The second summer, 2016, I did not water at all.  The winter snow that laid on the area for two or three months or more, had provided a good reservoir of moisture which saw the garden right through the summer.

The immediate effect after planting was of a lot of very small plants stranded in a gravelly desert.  I believe in buying small and being patient for a year or two while the plants bulk up, seed around and acclimatise to their environment.

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Just planted, June 2015

 

And, now, after another summer, they are starting to do so.  I see little “pups” on the Echinocereus.  There are Sedum and Stachys seedlings. The stars are the Opuntias (tree chollas and prickly pears) and the Delospermas.  These have grown quickly and the Delospermas were carpets of jewel-like flowers for months on end.  Dianthus and Artemisias are soft foils to their prickly companions. Groups of Nasella tennuissima provide a feathery backdrop and transition to greener and moister plantings at the rear.  The gentle movement of these grasses is a nice contrast to the static cactuses. The little species tulips ‘Persian Pearl’ popped up beautiful purple-red blooms with yellow centers in spring.  I hope to see more of these this coming spring.

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Tulipa pulchella @Persian Pearl’

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Delosperma ‘Fire Spinner’

 

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Summer, 2016 (after the hail storm had knocked off all the flowers!)

 

Now it is getting established, it really doesn’t require a lot work.  No watering if we have enough snow in winter.  Minimal weeding.  A gentle blow-off of leaves and some careful extracting of same from the Opuntias’ prickles with the kitchen tongs once in the fall.  That’s it.

I love my desert garden and see passers-by enjoying it too and that just adds to the pleasure for me.

PS:  Cactus? Cacti? Cactuses?  Who knows … ?? Who cares … !!

Anne Hughes/a Denver County Master Gardener

https://communityheroesgarden.jimdo.com/

http://www.botanicgardens.org/

www.coloradocactus.org

Hardy Succulents: Tough Plants for Every Climate by Gwen Moore Kelaidis. Publisher: Storey Publishing.

Cacti and Succulents for Cold Climates by Leo J Chance. Publisher: Timber Press

Plant List

Cactuses

Echinocereus coccineus

Echinocereus triglochidiatus ‘White Sands’

Escobaria forcottei ‘Koenesii’

Agave utahensis var. kiahabensis

Tree cholla – Opuntia imbricata var. arborescens ‘White Tower’

Tree cholla – Opuntia arborescens var. viridifloa ‘Santa Fe’

Creeping cholla – Opuntia clavata

Prickly pear – Opuntia x pinkavae

Texas red yucca – Hesperaloe parviflora

Yucca flacida ‘Bright Edge’

Herbaceous perennials, bulbs and grass

Dusty miller/artemisia – Artemisia ‘Beth Chatto’ & Artemisia absinthium ‘Silver Frost’

Woolly thyme – Thymus pseudolanuginosus

Yarrow – Achillea sps. various

Sedum- Sedum spectabile various

Pinks- Dianthus sps. various + garden cuttings

Rock rose – Helianthemum sp.

Ice plants – Delosperma ‘Fire Spinner’ &  ?

Two row stonecrop – Sedum spurium ‘Tricolor’

Other stonecrops – ‘Vera Jameson’, ‘Lidakense’, ‘Angelina’

Mullein – Verbascum bombyciferum ‘Polar Summer’

Lambs ears – Stachys byzantinus

Feathergrass – Nassella tenuissima ‘Ponytails’

Species tulip – Tulipa pulchella ‘Persian Pearl’

Trees 

Dwarf mugo pine – Pinus mugo  var. pumilio

Dwarf mugo pine – Pinus mugo ‘Teeny’

Under the Denver Sun

Beginnings of a Small Italian Garden

Italy. Hazy grey vistas are punctuated with narrow vertical trees. Nodding sunflowers laze in stony fields.  Knotty ancient thick-trunked olive trees hold forth in blazing sunlight. Window boxes are crammed full of vibrant red Pelargoniums or cascading petunias. Peeling walls, old doors and white sculptures are pierced with long rays. Shadowy evenings are filled with bees humming, and the breeze surprises with soft scents of lavender, roses and rosemary. Fountains play, and nearby the pergolas and arbors anchor verdant vines.  At once the designs are structured yet informal.  Italian gardeners tend to trim, pollard and generally shape many aspects of their plantings so keeping discipline within the freedom of the overall design. How could I bring these colors, textures and smells to a small sunny south-facing Colorado garden?

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Imposing Facade Bramasole, Cortona , Italy

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Roses, Lavender, Hibiscus, and Bees, Bramasole

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Blues in Foliage, Movement in Growth Pattern of Lavender Bed, and Lemon Trees in Movable Containers. Credit Patty Hollis Bramasole Photographs

We actually have some similarities here in Colorado to Tuscany: the purity of the sunlight, the ability to grow many of the same plants, and the often-disappointing soil!  Moreover, in Denver there is a propensity of Italian style houses needing yard work done, so as to create harmony with the home design.
We had this situation: a somewhat imposing stone house, with a tile roof, overwhelming a sad small lawned plot. We needed a plan that captured the essence of Italy. An Italian garden is rigid in some ways, but flowing and full of playful surprises as well. First, I put in the new curving flagstone pathways, then we had a focal point gate inserted in an existing wall (the only big expense), and I marked-out (with garden hoses) the new meandering borders for future flowerbeds.

Spring 2015, I laid six layers of newspaper, then topsoil and finally mulch (begged from a tree felling crew) on the new borders. Meanwhile, we planted the biggest items first so trees were positioned in the remaining grass areas. This stage included three small standard flamingo willow ball topiaries, and we were happy with how their pink spring delicate leaves brought in movement. In June I put in marker flags and then dug holes and planted the bulk of the borders.

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The New Reclaimed Border: Newspaper Layers, Topsoil and Mulch with Roses, Lavender, Speedwell, Tiny Dusty Miller, Boxwoods AND June Hail

From the house foundation to the front this was the order: Spiraea on one side (part sun), alongside large Rose of Sharon shrubs (full sun). Also, dusty pink climbing roses mixed with Russian sage were set-in at the base of the sunny wall. Then Moonstone™ floribundas were the next tall, back layer. Coming forward I placed Veronica (speedwell), and then lavender (both grouped in threes and fives), catmint (in a sometimes boggy drain outlet area), Bonica roses, and in front random plantings of soft grey Dusty Miller (which I planted as a annual but has thrived into this year). Finally, I nestled in boxwoods at the front of the new borders.

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New Garden Gate- Early Days

Boxwoods were intrinsic as a uniting design element, but I worried in this hot aspect that they might not thrive. They have done well so far (after some initial winter bronzing that righted itself) and although slow growing they add dark green shiny all-year round formality. I planted many more this year, and slowly I will add different sizes to bulk out the design. Also, I just put in a mixture of own-root end-of-year bargain miniature roses, in the same soft pink scheme.  Someone else might have chosen to go for more vibrant colors in so much sunshine, but for us the dusty pink and muted blue palette suited and followed our Tuscan inspiration.

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Cosmos: First Year Quick Dramatic Interest with Daisies and Spiraea

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Boxwood, Roses, Catmint, Russian Sage, Climbing New Dawn Roses and Trumpet Vine

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Moonstone Rose Large and Long Lasting

There was also an arid area around a large blue spruce so my latest additions have been barberries, grasses and low growing, tight growth junipers.

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Dwarf Hameln Grass, Barberry and Blue Spruce

Additionally, we have a small curved 270’ pathway that needed a focal point. I had a thriving eight foot Aspen, along with cankers and overnight new saplings.  It did hurt to rip it out, but it needed to be done. Ideally, a hundred year old olive tree was called for. But for a substitute we have just planted a Twisty Baby Black Locust to add the gnarly element that mimics a grand olive tree. I have given it a weekly dose of sugar water to possibly help with rather dramatic transplant shock more information here. This specimen tree should be interesting winter interest too, and we are hoping in time it will produce its lovely large white spring blossom.

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Dramatically Staked Rather Droopy New “Twisty Baby”

 

Recently we were pleased with how things were shaping up, but we still felt our house overwhelmed the plot and we were missing some movement, texture and color. I realized the design was devoid of a crucial element that separates the Italian landscape from any other, and without which Tuscany and even Renaissance landscape paintings would be dull.  The strong narrow verticals dotting all the land, lining the roads to cemeteries and grand villas.  I needed some upward movement.  In lieu of cypress I have planted, somewhat symmetrically, some Blue Arrows and Medora junipers. They have added the strong missing element, and should be interesting in our monochromatic winters.

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Assisi, Umbria Vertical Inspiration

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2017 One of the New Vertical Evergreens

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Whimsy. Perfumed and Perfect

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Structure in the Design, Clipped Hedges and Flamingo Willows.

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Blue Arrow Vertical Defining House with Speedwell & Sweet Drift Rose

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Part Sun Textural Plantings and New Verticals.

Late summer sees our humble garden at its best.  It is textural, perfumed and the air is filled with bees. As the boxwoods grow larger, and the narrow upright junipers extend upwards, the design will strengthen.  But for the moment I am content with the first steps on this project. Once established it has been low maintenance, with little room for weeds to grow. Ideal additions would be a little flagstone wall to step the front lawn, more beds, a sculpture or a sundial, and citrus in movable pots.
Anne Beletic.
A Denver County Apprentice Master Gardener

Appendix : Other Images Showing Details

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Bees and Hummingbirds

List of Main Plants:

Barberry: Berberis thunbergii for winter interest; slow growing  and perfect in front of blue spruce and Spiraea)

Lavender ‘Munstead’: Lavandula angustifolia for bees and constant summer blooming

Lavandin: L. angustifolia x L. latifolia

Russian sage:  Perovskia atriplicifolia  as a foil for roses and kept in check behind them

Catmint ‘Walker’s Low’: Nepeta racemosa covers unsightly gutter and run off area

Dusty miller: Jacobaea maritima gives a lot of bang for the buck and adds amazing light grey and texture to the design; much taller than the 10” I expected!

Speedwell: Veronica longifolia was cut well back in July for a substantial second bloom

Yellow trumpet creeper: Campsis radicans  f. flava Still waiting for flowers- value to be decided!

Junipers:  Juniperus scopulorum ‘Medora’ and Juniperus scopulorum ‘Blue Arrow’

Flamingo willow: Salix integra ‘Flamingo’

Boxwoods: Buxus sps

Black locust : Robinia pseudoacacia  Twisty Baby™

Roses:  ‘New Dawn’ – climbing; ‘Moonstone’™ – floribunda, highest maintenance, has had aphids, rose midge and very bothered by Japanese beetles, but are flourishing at end of summer with massive blooms; ‘Nearly Wild’; Bonica™; Blushing Knockout®; Pink Double Knockout®; Sweet Drift®; Whimsy™ – miniature, amazing fragrance.

Pre-existing:

Michaelmas daisy:  Symphyotrichum novae-angliae

Spiraea  sp. Large and formally cut box shape house foundation plant, dark green leaf and few white flowers

Spindle:  Euonymus japonicus

Rose of Sharon: probably Hibiscus syriacus ‘Collie Mullens– has  very short “giving season” but is glorious August and September.

Semi Arid area under blue spruce tree:

Red barberry:  Berberis thunbergii

Mound grass: Pennisetum alopecuroides ‘Hameln’ – divided and planted late summer, so hoping it will thrive

Juniper: Juniperus squamata ‘Blue Star – hoping to block out bindweed in time

Annuals:

Red fountain grass: Pennisetum setaceum ‘Rubrum’

Verbena  sps – in pots with boxwood 2016

Pelargoniums: Pelargonium peltatum ‘Contessa White’ – ivy’type for window boxes. I didn’t actually succeed in overwintering these and expense prohibited from re-buying, also they were not exactly an ivy geranium in their growth pattern, having only a slight “tip-over”

Other Plantings:

Bulbs, Cosmos, Chinese bellflower – Platycodon grandiflorus-  and ground covers including several Veronicas

List to do in Fall:

Anti-desiccant spray liberally on boxwoods and young evergreens

Wrap trunks of new trees

Twine wrapped around length of blue arrows (so snow doesn’t open the growth)

Collar grafted floribunda roses, pile mulch around other roses

Fertilize remaining lawn

Top-up mulch for general root protection and neatness esthetics (dark brown)