2024 Denver Master Gardener Plant Sale – Saturday, May 18 & Sunday, May 19 2024 – An All-Weather Event You Can Count On!

By: Lori Williams – CSU Extension-Denver Master Gardener since 2016

The 2024 CSU Extension Denver Master Gardener Plant Sale features more than 150 of varieties of perpetual vegetable winners, including a huge selection of hybrid and heirloom tomatoes, delicious culinary herbs, and more than 25 chile pepper strains (sweet, hot, sweet-hot, hot and hot-hot)! For a full list of what will be offered, visit here. We offer gorgeous, healthy plants for your garden: many you’re likely familiar with and some fun new ones to get your garden possibilities growing! All veggies and herbs are $7 each. Annual flowers will also be available. Come early for best selection. Bring your own flat or totes if you can!

Renata Hahn, pictured here, is among the 50 volunteers who grew more than 150 plant varieties from seed (that’s 10,000+ plants!) for the plant sale!

With planting time just around the corner, many gardeners are looking forward to getting into the soil and chocking it full of robust bedding plants. Volunteers will be on hand to advise on varieties, planting practices and gardening in general – Ask US!! When you take your baby plants home from the sale, here are some important tips to first harden them off, as they will be fresh out of the greenhouse.

An exciting addition to the sale this year is a native plant selection. Five different species will be offered for $9 each, including: Large-Flowered Penstemon, Switchgrass, Mexican Hat, Butterfly Weed, and Evening Primrose. These are expected to go fast! With each plant purchased, native seeds will be given away (while supplies last). Salegoers can view a native garden planted last season, and the Front Range chapter of WildOnes.org will have a table.

Also during the sale, you’ll enjoy gardening demonstrations and an “Ask a Master Gardener” booth for your gardening questions. CSU Extension will have research-based resources for home gardeners, as well as education and nutrition information. New this year, Denver Master Gardeners will sell seeds for cool-season crops (like peas and spinach that can be direct sown).  A selection of native plants and perennials will also be offered!

Do you garden in containers or raised beds? Interested in interplanting veggies, flowers and herbs? Maybe you’ve been curious about block style garden layouts? Community gardens offer great gardening options, too. Our partners at DUG have all kinds of useful information here. Fresh vegetables and herbs will make you glad for the space and time you spend this season on growing fresh, flavor-rich, nutritious food for you and your loved ones.

Find all your faves & diverse new selections.

Denver Master Gardener volunteers are heroic in their commitment to get the healthiest, prettiest seedlings to YOU for your 2024 growing season – no matter the weather! A Colorado spring day can bring rain, sleet, snow, and sun – in no particular order. Regardless of temps, winds, or precip, our volunteers are excited to get these lovely bedding plants into your hands. We will be there, ready to help you! 

We look forward to seeing you May 18 & 19!

Maybe you’re also interested in becoming a Colorado Master Gardener? Come grow your experience and learn about the many gardening options, being a Master Gardener, and the amazing resources available to you through CSU Extension! 

Natives, Nativars, and Genetic Consequences

By Terry Deem-Reilly, CSU Extension – Denver Master Gardener since 2003

A LITTLE BACKGROUND ON THE SUBJECT

The question of whether certain gardening practices help or harm the natural world has become a major consideration in recent years. Consequently, gardeners have adopted strategies to support our ecosystem, especially by including native and adapted plants to foster genetic diversity and the flourishing of local mammals, birds, and insects. These creatures, having evolved alongside our native plants, are attracted to natives for food and protection, while spreading the pollen necessary for the plants’ seed production and propagation.

Gardeners’ enthusiasm for the use of natives has sparked the production and sale of this class of plants through catalogs and nurseries and its promotion in gardening literature.  Where once only new varieties of old standards were garden possibilities, we now have expanding availability of natives. Add the general concern about climate change and sustainability to the mix, and we’re pretty much sold on this class of plants!

When a new class of sexy plants bursts upon the market, the demand is ever-increasing and intense. There also aren’t enough true natives in a sufficient variety to fulfill our cravings for unusual colors, sizes, foliage, and blooms. Given this, huge numbers of native plant cultivars – known as “nativars” – have emerged to fill the gap. This seems like a textbook operation of market forces, except for one thing: the effects of planting nativars on our cherished natives and, by extension, on the entire ecosystem are big, big unknowns.

LET’S DEFINE SOME TERMS

Before getting into the tall grass on this question, we’ll add some definitions:

• “Native” refers to a plant that was growing in the Americas before widespread European settlement, which began about 200 years ago.
• “Cultivar” designates a plant selected and bred for certain traits that is (usually) propagated by cloning. Many are the results of crossbreeding between species and (sometimes) genera.
• A “nativar” is a cultivar of a native plant that often produces sterile flowers (and therefore won’t reseed itself). It’s usually identified by genus, species, and a cultivar name in quotes, e.g. Physocarpus opulifolius ‘Red Robe,’ as opposed to the native ninebark, known as just plain Physocarpus opulifolius.

A FEW THINGS TO THINK ABOUT

Natives have been growing and evolving alongside their pollinators and other wildlife without human intervention for millennia; plants, animals, and insects have formed a nice symbiosis that supplies all involved with sufficient food, shelter, and opportunities to reproduce. But now humans are introducing new factors into ancient relationships that may affect our ecosystems in unknown ways for a long period of time. Gardeners should therefore think carefully about the desirability of introducing nativars created by unnatural means into a natural environment.

Popular horticultural literature and educational programs haven’t addressed this issue, but organizations devoted to best horticultural knowledge and practices have compiled science-based publications (including extensive reference lists) that shed a great deal of light on the pros and cons of using nativars in home gardens.

Let’s examine seven misperceptions about nativars, courtesy of the Maryland Cooperative Extension:

• It’s always bad to use nativars. Nope. Sterile nativars (look for blossoms that lack stamens) aren’t harmful, and some nativars are being bred for disease and pest-resistant features.
• The number of plants in cultivated gardens is outnumbered by natives in the wild. Numbers don’t necessarily translate into impact. And wild areas often occupy much less land than developed areas.
• Urban nativars can’t interbreed with natives in natural areas. Wind-borne pollen can travel a long way, and some pollinators are migratory.
• Adding nativar genes into native populations increases genetic diversity. This might be true if diversity is adaptive, not random (as with plants introduced by humans). And a nativar bred for higher vigor can compete with natives to the detriment of the latter.
• Plants’ performance is best measured by how often they’re visited by pollinators. Disruption of the natural balance cancels out perceived advantages of increased visits.
• Nativars created by spontaneous mutations (“sports”) don’t affect the ecosystem. Sports can be produced by recessive genes resulting from inbreeding, and random mutations lack the adaptability characteristic of native plants.

RESOURCES

CSU Extension takes no position pro or con concerning nativars, but I’m offering some helpful online resources below for further research. And of course, Denver County Extension stands ready to assist with information about this and any other horticultural concern!

Native vs. “nativar” – do cultivars of native plants have the same benefits?

A Guide to Native Plants: Straight Species vs. Nativars

The Nativar Conundrum: New Research on Natives vs. Native Cultivars with Dr. Doug Tallamy

REFERENCES

Cultivars of Native Plants | University of Maryland Extension. (n.d.). Extension.umd.edu. https://extension.umd.edu/resource/cultivars-native-plants/

Keeping Nature Near. (n.d.). Grow Native! https://grownative.org

Renovating a Native Plant Demonstration Garden

By Kathy Roth, CSU Extension – Denver Master Gardener since 2018

Denver Extension’s new Native Plant Demonstration Garden is in the ground! The old garden, installed in 2014, had fallen into a tangle of weeds and only a few native species remained. Given this, in May 2022, a group of interested Denver Master Gardeners decided to give it an overhaul and tasked themselves with brainstorming a new design. Their goal: showcase native plants that promote biodiversity, support pollinators and wildlife, and thrive in urban gardens.

Committee reviews initial design plans. Photo by Anne Hughes

The committee’s first order of business, using resources available from CSU Extension like this Fact Sheet and this publication from the Colorado Native Plant Society, was to determine what could be salvaged and what needed to be demolished. Field trips to demonstration gardens in neighboring counties fueled their knowledge. After discussion and research, they created a new design and planting plan.

^{Planting plan by Nancy Downs. Photo by Kathy Roth}

Next, the group made choices about installation. They decided against soil amendment, in part to avoid stirring up weed seeds, but also because natives do not require nutrient rich or high organic soils; natives grow successfully in unamended soil. For mulch, the group opted for squeegee. This was following Douglas County Horticulture Agent John Murgel’s compelling argument that rock less than 3/8” in size maximizes soil water penetration. 

Denver Extension is located in the city’s Harvard Gulch Park, so we were fortunate to get lots of help from Denver Parks and Recreation. Our start was delayed week after week by relentless spring rain which turned the site into a swamp. Finally, Jared McQueer, DPR Median Renovations Operations Supervisor, and his crew were able to demo and grade the site, construct the hardscape elements, and install irrigation. Surprisingly, we chose pop-up sprays instead of drip because DPR has had bad experiences with rodents damaging drip lines in city parks.

DPR crew demolishing site. Photo by Anne Hughes

Propagating and acquiring native plants can be a challenge. We lucked out because the partnership with DPR meant Holly Shields, DPR Greenhouse Supervisor, grew our plants in the City Greenhouse.

Plants staged in Extension Office. Photo by Anne Hughes

When skies finally cleared at the end of June, team member Dudley Clark kicked off planting week by coordinating construction of a temporary rabbit fence around the garden perimeter to protect the small plants from being devoured before they even got started. To our amusement, we discovered several days later that we had fenced in a rabbit! To everyone’s relief – including the rabbit’s – we corralled it and relocated it back to the park.

We used a planting technique called “bare rooting” to plant. Supposedly, it promotes immediate contact between soil and roots which translates to less transplant shock. For more on bare root planting, watch this video from Denver Botanic horticulturist Grace Johnson. 

Our planting crew. Photo by Anne Hughes

Volunteers checked the garden daily the first month to monitor water and to keep ahead of weeds. We’ve been lucky so far. There is some prostrate spurge, an annual weed that is easily pulled, but milkweed is a problem because although native, it spreads by rhizomes and quickly forms unwanted colonies.

We lost a few plants but not many. The Gambel Oaks have struggled the most and just when we thought they had adapted, something started eating the foliage. However, given how small the plants were and how hot it was the week we planted, we are amazed at how good everything looks and how quickly plants are establishing. We plan to leave the fence up through the winter but by next season the plants should be established enough to fend for themselves. 

Next up is signage. Our plan is to label plants and include QR codes that link to educational materials on the Denver Extension website. Come next spring, visitors will be able to see the garden’s progress and follow along through the seasons.

Denver Extension thanks the Denver Master Gardeners and the DPR crew for their help with this project.

Beeing a Beekeeper

By Tracy Dunning CSU Extension – Denver County Apprentice Master Gardener, 2023

Author and backyard hive. Photo: Eric Sondermann

During Pollinator Week, you may be curious about being a beekeeper. As an urban beekeeper, let me share information about considerations in starting a hive, costs in time and money, equipment, and lessons learned in my beekeeping years.

Many people think that honey bees are endangered, but actually they are thriving in many ways. It is the other 945 species of native bees that we also rely on for pollination that are threatened, and sometimes it’s because of the competition with the honey bees.

One can only imagine how much work and how many flowers are visited as it takes 12 honey bees their entire life to make 1 teaspoon of honey according to Lisa Mason, CSU Extension County Specialist.

Considerations in Starting a Hive

It is important to think about your goals and expectations before jumping into the fascinating world of beekeeping. Do you want the honey, the beeswax, to save the bees (which don’t need saving), to learn a new and fascinating skill?

Things to consider:

• How will you learn beekeeping – a mentor, classes, or associations such as the Colorado State Beekeepers Association?
• Time commitment for inspections, mite checks, harvesting honey.
• Check the local ordinances for your community or HOA.
• Follow guidelines for hive placement in your community and for the bee’s well-being.
• Cost: usually $500-$1000 to start, but my experience was very different (see below).
• Selling honey requires following special rules for cottage industries.
• Weather changes and extremes in Colorado make for challenges.
• Be sure to tell your neighbors and give them periodic jars of honey for good relations.

Equipment

Hive box: There are three main types of hive boxes: the more common Langstroth, the Top Bar, and the Flow Hive. See this video from Adams County Extension for details.

Tools: Brush, hive tool, smoker. Photo: Tracy Dunning

Tools: The basic tools are a brush, a hive tool for prying the frames out, and a smoker for calming the bees when doing an inspection.

Protective clothing: Depending on your comfort level, you may need gloves, a hood to protect your face, a bee shirt or a full suit. You may notice in the video link below that the beekeeper is barehanded; some beekeepers do not use protective clothing as most bees will not sting unless in self-defense.

Getting the Bees

There are several ways to get your initial bees:

• Buy them as a package of bees or a nuc. Cost is usually $100-$350. Here is a video of Adams County Extension putting the queen and bees from a bee package into a hive.
• Beekeepers will often split their hive to prevent a swarm.
• Catch a swarm which is how I started and it’s free. (My hive box was also a free hand-me-down.)
• Find more on costs of beekeeping here.

Author setup to catch a swarm above the box on the fence. Photo: Ted Ramsey

Lessons Learned

• Some beekeepers intensely practice their craft with monthly inspections, special feeding, marking the queen, etc. Even with managed care there is a 30-60% hive loss. My approach with my mentor has been more hands off, believing that the bees have been managing on their own for hundreds of years.
• It is, however, important to treat for mites on a yearly basis. This Integrative Hive Management Guide provides detail.
• Having a variety of flowering plants all season long is important as the bees need a supply of nectar and pollen. Native plants are the best, and double flowers with lots of petals are less visited. Find excellent information on feeding bees here.

Honey bee on Biokovo Cranesbill – notice pollen on abdomen and on legs under wing. Photo: Tracy Dunning

• One time I was appalled to find a pile of dead bees outside the hive. I didn’t realize that in winter, the drones are all kicked out of the hive so they don’t eat the honey.
• My hive swarmed a couple of times when we didn’t split in time. This is when there are many bees so a new queen is created and the old queen leaves with half the bees. This means that there may not be much honey to harvest that year as bees need 80 pounds of honey to overwinter.
• Be sure that you have a shallow water source nearby; my neighbors didn’t appreciate all the bees drinking from their pool.
• Many hives were lost in the deep freeze last winter, but putting insulated boards and pads around the hive protected my bees. They are amazing as they stay warm by huddling in the center of the hive, flapping wings to generate heat, and rotating from the outside to the inside of the huddle.
• Although some beekeepers don’t mind getting stung, one friend eventually developed an anaphylactic reaction and had to give up beekeeping altogether. I prefer to stay protected when opening the hive.

Backyard beehive with variety of flowers for nectar and pollen. Photo: Tracy Dunning

Watching bees closely and learning to be a beekeeper is a wonderful experience. Is it right for you? This is a great resource to help you decide.

Planning a Garden for Thrills Spring to Fall

By Terry Deem-Reilly, CSU Extension – Denver County Master Gardener since 2003

One of the most satisfying aspects of gardening is seeing dormant sticks, clumps, and bulbs that were placed so hopefully in the soil leaf, blossom, and fruit. At the same time, one of the most daunting aspects of gardening is ensuring that all of that leafing, blossoming, and fruiting doesn’t occur all at one time. A garden that ceases to bloom after the last tulip has disappeared or browns up from the fall equinox until the following spring won’t satisfy the senses nearly as much as one that displays continuous interest. Moreover, landscapes which produce pollen and nectar throughout the season provide important nourishment for pollinators.

Hellebores kick off the season. Pixabay.com

Other posts in this blog have stressed the necessity of matching plants to sites, soil, and sun exposure that will allow them to flourish. Horticultural considerations don’t disappear when the goal is season-long color and interest; selecting plants that like the same conditions and grouping them into the areas where they’re most likely to flourish are indispensable to having the three-season garden of your dreams.

The detailed first steps to success with any perennial garden can’t be adequately covered here but are well-explained in the Extension fact sheet Perennial Gardening. Remember the conditions in your site when reviewing plant lists.

Next, consider whether you’d like to include non-native or xeric/native trees, perennials, and shrubs; this decision will determine the amount of time and attention (not to mention water) you’re going to devote to a three-season garden. Xeric plants and Western natives won’t need much maintenance after the first season or two, but a lush English-style bed of roses, delphiniums, and pinks demands careful soil amendment and regular irrigation, mulching, and fertilization. Decide what look you’re after and what it will take to achieve it.

Mid-summer morning & the garden’s in full bloom. Photo: Linda McDonnell

To make plant selection a little easier, here are suggestions from plant lists showing seasonal bloom by non-xeric and xeric/native varieties, with links to the complete lists for easy reference.

Nonxeric or Non-Native Perennials

• Spring: early blooming bulbs, primrose, candytuft, viola, creeping phlox, hellebore, peony, geranium
• Summer: garden phlox, dianthus, lily, verbascum, hosta, campanula
• Fall: aster, chrysanthemum, Japanese anemone, lobelia

For the complete list, see the Plan Your Garden with our Perennial Flowering Plants by Season Guide. Some of the plants shown above also appear in 25 Perennial Flowers That Bloom From Spring To Fall. Timberline Landscaping in Colorado Springs has published a bloom calendar of perennials that do well on the Front Range.

Xeric and/or Native Perennials

• Spring: early blooming bulbs, columbine, amsonia, windflower, pasque flower
• Summer: chocolate flower, poppy mallow, asclepias, eriogonum, penstemon, oenothera
• Fall: helianthus, asclepias, winecups, hyssop, agastache

These plants, and many others, can be found in these Extension fact sheets: Native Herbaceous Perennials for Colorado Landscapes and Xeriscaping: Perennials and Annual Flowers. These resources also indicate water needs, light requirements, and plant heights and descriptions.

Want to see more native plants? CSU’s Low-Water Native Plants for Colorado Gardens: Front Range & Foothills includes not only common and botanical names; height; color, size, water and sun requirements; and wildlife value, but also design plans and photos of great local native gardens. Mountain residents will find the Extension fact sheet  Flowers for Mountain Communities useful for plant selection and advice on cultivation.

Shrubs and Trees

Hawthorn tree in fall. Pixabay.com

Our guide wouldn’t be complete without recommendations for suitable trees and shrubs to supplement your perennial display. Many plants in these categories offer blossoms, fruits, and/or color that add interest throughout the season; a number of them offer all three!

Here are examples of shrubs that add color and interest through the seasons:

• Serviceberry
• Fremont mahonia
• American plum
• Buffaloberry
• Western sand cherry

For a complete list, consult the Extension fact sheet Native Shrubs for Colorado Landscapes. Again, you’ll see botanical and common names, size, and sun, moisture, and sun requirements for each shrub.

Some trees that add interest include:

• European mountain ash
• Pine
• Colorado blue spruce
• Aspen (Foothills and submontane areas only!)
• Maple

See the fact sheet Native Trees for Colorado Landscapes and the CSU publication Recommended Trees for Colorado Front Range Communities for more details. Mountain gardeners should consult the fact sheet Trees and Shrubs for Mountain Areas for suggestions.

Finally, don’t discount the value of roses when planning for season-long color. Even with the plague of the Japanese beetle, roses (especially hip-bearing and species roses) dependably add color through the growing season. The Denver Rose Society publishes a list of the best roses for our climate: Recommended Roses for Colorado.

If problems arise, always, ALWAYS rely on research-based information to answer your questions;  Denver Extension stands ready to help!

Experimenting with Winter Seed Propagation

By Lori Williams, CSU Extension – Denver Master Gardener since 2016

 I hope my winter experiment yields beautiful Echinacea plants this summer! Image: Flickr

I’m a fan of the gardening podcast “A Way to Garden” hosted by Margaret Roach, columnist for The New York Times. Recently she interviewed Heather McCargo, founder of the Wild Seed Project, a horticulturist-supported non-profit based in Maine. The organization is committed to building awareness of native plants, the importance of increasing biodiversity, and ethical seed collection. Find the full interview here.

Their discussion of outdoor winter seed sowing really piqued my interest. Had I ever given much thought to winter sun, precipitation and temperatures being necessary for native seeds to germinate? Honestly? No. 

The suggested timing for winter seed propagation – start after the holidays – also caught my attention. It all sounded pretty simple. Start by gathering on-hand garden supplies and seeds collected from my yard and other gardeners and find an appropriate winter location for the pots to live. The genuine bonus of growing a few of my own perennials was just too intriguing not to try. I was inspired!

Everything needed for winter propagation of seeds that not only survive winter but germinate because of winter. Photo: Lori Williams

Materials

• Containers roughly 4-8” wide, avoid biodegradable pots as they will likely break down in winter weather.
• Seeds – discover germination guidelines and other seed information for Colorado here.
• Organic, compost-based potting soil is recommended because it’s filled with different microorganisms. Please note, compost is not recommended for Colorado native plants as they prefer a ‘leaner,’ less organic soil. Find info on propagating our regional natives here and in CSU’s fact sheet 7.242.
• Coarse sand to cover seeds after planting assists seeds in staying lodged in planting medium and allows light to reach them.
• Group containers, flats, etc. and cover with wire screen, anchored with bricks or rocks, for squirrel protection.
• Label pots to avoid forgetting what seeds were planted where. Pencil on plastic tags really does work best.

January 17th was 38℉ & partly cloudy, a cold breeze bringing in a big snow, I wanted my seeds to benefit from the predicted precip. Photo: Lori Williams

Location

• A level, shaded area for containers to endure winter undisturbed. Shade is essential during sunny, warm days so pots don’t overheat and dry out. Keep containers level so seeds don’t float or splash out during heavy precipitation.

Ethical Seeds

The Wild Seed Project stresses collecting and using seeds native to your location. Collecting native seed from public lands and in the wild (in Maine, Colorado, and most of the nation) is typically a huge no-no (AKA unethical) so how do we collect seeds ethically? 

• Seed from our own gardens are the easiest to collect. 
• The friendly approach of asking ‘May I gather a few seeds from your XYZ perennial? I’d love to try to grow it.’  
• Seed swaps are another excellent resource and a request on social media can produce great results. 
• Wild Seed Project and other ethical seed providers offer native seeds for purchase. 

Buy seeds suitable to your growing conditions, of course, and be familiar with what those plant seeds look like. As a newbie gardener, I planted dried Echinacea flower petals twice thinking they were seeds. 

My Project

While I did not have native seeds for my backyard experiment, I did have ethically collected seeds from non-natives. I planted three flats with Echinacea and lavender seeds from my garden and seeds from a divine lupine that was a volunteer in a friend’s yard. On January 17th I placed my pots in deep shade against the house with bricks holding the screen cover in place. That evening 6.5” of snow fell and temps stayed cold for weeks afterward. 

Snow covered since January 17^th, it took the snow on my flats until the end of February to finally melt. Photo: Lori Williams

Outdoor winter propagation is challenging for the impatient gardener (me) but my long game of possibly growing some perennials of my own from seed has me hopeful. With more Colorado snow and cold ahead, my flats remain undisturbed in the shade. I resisted the urge to water them during the last several weeks of no moisture – and then we had a welcome icy rain turning into snow – YES! 

As my flats have yet to show any noticeable growth, I am watching for signs of success during our longer days accompanied by the sun beaming from higher in the sky. 

Looking Forward: A Lower Maintenance Garden with Native Plants, Fruit Trees, and Shrubs

By Felicia Brower, CSU Extension-Denver Master Gardener since 2020

Now that the 2022 summer season is winding down, it’s a great time to review what worked in the garden and what didn’t and to start planning for next year. (Keeping a garden journal throughout the season saves time and makes this much easier!)

Start by asking yourself the following questions:

• What grew well this season?
• What didn’t grow as well as you would have liked? Any idea why?
• Did you struggle with pests or disease?
• What do you want to plant next year?

After you have the answers to those questions, you can begin to make a plan to fix any problems that popped up or to repeat your successes next season.

As far as what grew well in my garden this year goes, I planted more localized seeds this year because seeds bred for our specific climate tend to have fewer days to maturity and produce more drought-tolerant plants than ones grown from other seeds I’ve used. They fare better in my garden and will be a staple every year moving forward.

Photo credit: Felicia Brower

That being said, my garden got off to a rough start this year thanks to pest problems, extreme heat, and watering issues. Many of the seedlings I started inside were immediately eaten after being transplanted outdoors, and it seemed like no amount of diatomaceous earth could help. I wasn’t watering enough to combat the weeks of 100° sunny weather, and the growth of a lot of my vegetables suffered because of it. I was recently able to get things under control (better late in the season than never!) and my vegetables and flowers have finally started growing the way that I had hoped they would. I’ll be spending the winter learning more about Integrated Pest Management (IPM) and effective watering techniques to make the most of water during a drought.

As I look at what I’d like to change in my garden next summer, one big one is that despite loving it, I want to spend less time doing maintenance in it. I spent much more time weeding and trying to problem solve than I would have liked, and a few adjustments could make a very big difference.

The biggest change is going to be adding more native herbaceous perennials and fruit shrubs and trees in the yard. My hope is that by making the investment to fill out those open spaces, the weeds I spent so much time pulling will be unable to take over, and I’ll end up with beautiful, lower-maintenance native flowers, shrubs, and trees.

Here are a few of the plants on my list for next year:

FLOWERS

I usually plant vegetables and annual flowers, but after seeing the perennials that I planted last year pop up this year without having to start anything inside, I’m making a big shift to focus on native flowers and herbs that come back without any effort from me.

Blanket flower. Photo credit: Canva

Having perennials show up in the spring will add much-needed greenery to the yard after a cold winter, and I look forward to the pops of color they’ll provide throughout the summer and into fall. I can’t get enough of the vibrant red and yellow petals of blanket flower (Gaillardia aristata) and plan on adding some big patches of it to my garden next year. I’ll also be looking into adding more penstemon (Penstemen spp.) to the landscape. With more than 60 native penstemons to choose from, these easy-growers range in size from a few inches to a foot or two tall with long flowering spikes.

Chocolate flower. Photo credit: Canva

Chocolate flower’s (Berlandiera lyrata) yellow daisy-like flowers have a wonderful scent and typically flower from June until frost. Goldenrod (Solidago spp.) produces tall bursts of yellow blooms later in the summer, from August until November and is known for being easy to grow and care for.

SHRUBS

Shrubs, specifically ones that produce fruit, are going to take a lot of space in my yard next year. Drought-tolerant gooseberries and currants grow especially well in our area, and their berries can be eaten fresh or used to make delicious jams and pies.

Gooseberries. Photo credit: Canva

I have a raspberry patch that I plan on expanding to different areas of the yard. These prolific growers will take up a lot of space and provide delicious snacks while I’m out harvesting and fresh berries for some new recipes I want to try. Serviceberry is cold-hardy and drought-resistant, making it a no brainer for someone looking for a low-maintenance addition to the garden. The fruit also happens to be high in vitamins and is comparable to blueberries but with a slight apple flavor.

Serviceberry. Photo credit: Canva

TREES

Trees are a big investment and a lot of planning needs to go into which trees will be planted and where. For fruit trees, I’d like to plant plums, since they’re considered very dependable for this area, and a peach tree. Peaches can be a higher risk tree because late frosts can damage blooms and prevent peaches from developing, but I think it’d be fun to have a self-fruiting dwarf variety that can still provide shade and habitat for animals even when it’s not fruiting.

---

After planting all of the fruiting trees and shrubs, I’ll have an abundance of produce in my yard for years to come that I’ll be able to preserve and share with neighbors and members of my community through programs like Grow & Give. It’ll take a few years, but after everything’s established, I’ll only need to worry about planting my vegetables annually, which I also plan to scale back on…eventually. For now, my focus is on finding the plants that I want to get in the ground this fall and next spring, filling out the landscape, and learning as much as I can about how to help everything in my garden thrive.

—

Watch for future ‘Looking Forward‘ posts where we’ll spotlight Master Gardeners who are applying what they’ve learned to expand, rethink, or improve their gardens.

A Gardening Project for the Hell Strip

By Gail Leidigh, CSU Extension-Denver Master Gardener since 2021

One of my goals this summer was to fix up a small 9’ x 6’ section of the hell strip area that I have ignored for several years while the weeds thrived. Between weeds, trash, and being a favorite spot for the neighborhood doggies, it was quite an eyesore. So, I finally decided to tackle this project and do something that would be sustainable, pleasant to look at, and attract pollinators.

Sad state of the hell strip in early April 2022. Photo by G. Leidigh

Over the winter I worked on a plan, and first, needed to do some research! Since I live in a historic district, I consulted the guidelines published by the Denver Landmark Preservation Commission, which recommends that homeowners “Maintain grass and/or low-water ground cover in an existing or new tree lawn (the landscaped area between the street and the sidewalk).” Since the tree lawn (isn’t that term so much more charming than hell strip?) was long gone, and I did not wish to irrigate the area, I wanted to go with low-water plantings.

For inspiration, I did lots of reading from various sources, including an earlier post on this blog, Reimagining a Denver Hell Strip, which detailed the process Denver Master Gardeners Elizabeth and Daniel Neufeld used to transform their space. If they happen to read this, I’d love to know how it looks now!

5280 magazine also has a helpful article from 2015 with locally specific suggestions on planting in the hell strip.

I also borrowed the library book Hellstrip Gardening: Create a Paradise Between the Sidewalk and Curb by Evelyn J. Hadden (2014) for some very interesting gardening ideas from around the United States.

Once the weather began warming enough to work outside, I started clearing the area of debris and had a small elm tree that had grown itself from seed dug out. I did not know what to expect as far as soil conditions and anticipated that I’d need to remove and replace loads of dirt. But to my pleasant surprise the soil was quite loose, loamy, and I would be able to plant without amendments!

Naturally, as the weather continued to warm, the weeds were growing like crazy, and I spent many, many, hours digging them out and getting their roots as best I could. I will need to stay on top of these weeds throughout the season this year, and hopefully the healthy new plants will eventually crowd them out.

In choosing plants I looked at information on recommended native plants on the CSU Extension website, and using the wonderful “Find a Plant” feature on the Plant Select website.

Plant choices were narrowed down based on my must-have criteria: safe for kids and pets, low-height (24” or less), low water needs, poor soil (non-composted) tolerant, and overall tough plants that could deal with being in a busy high traffic area.

I ended up selecting Kannah Creek Sulphur Buckwheat (Eriogonum umbellatum) and Wild blue flax (Linium lewisii). The area is 54 square feet, and I drew up some plans to help with arranging things.

After some friend and family feedback, our top choice plan. Photo by G. Leidigh

In typical Colorado fashion, as soon as I finished planting everything in mid-May, after I thought the danger of frost had passed, we got one of our wild late spring snowstorms extra late this year.

Protecting plants from snow on May 19^th. Photo by G. Leidigh

Thankfully, the snow in our area remained mostly wet slush which prevented most of the heavy build up on plants and trees that causes problems. Unfortunately, other areas were not so lucky: while driving through Washington Park after the storm, I saw significant damage to older trees throughout that neighborhood.

I put a small fence around the area to keep out wandering feet and covered the garden bed with pea gravel (the suggested mulch for these two plants). I have been watering about every 2-3 days by hand, which is more frequent than I would suggest for clay or rich soils, but this small space has exceptionally well-drained soil and I want to make sure to get the plants established during this rather warm and dry spring and summer. All of the plants have shown good growth in the last two months, and for now they appear to be happy in this place!

I can’t wait to see blooms here in the future! Photo by G. Leidigh

Designing a Garden Using Xeriscape and Colorado Native Plants

By Terry Deem-Reilly, CSU Extension-Denver Master Gardener since 2003

Sustainability has become a byword in many areas of life, so why not apply the concept to our gardening by using the plants best suited to the challenging Colorado climate, as they love sun and low irrigation and flourish in soils with very little organic material and no fertilization? 

Planting xeric and Colorado native species in our gardens isn’t only a smart choice during drought conditions, but will save time in the garden, improve the looks of our properties and our neighborhoods, and support necessary pollinators and other wildlife in our ever-expanding urban areas.

Island Grove Demo Garden, City of Greeley (Flickr)

Basic Garden Design

Before selecting and buying plants, consider basic design principles (as slightly modified for a xeriscape/native garden):

• How big is the garden going to be, where will it be placed, and what other uses will be made of the site and the surrounding area? 
• Is the ground level, sloped, or a combination of the two? (Water will run down a slope to collect at its foot, which will affect the placement of plants: more xeric plants belong at the top, less xeric at the bottom.)
• Consider the soil type (clay, sand, or loam), sun exposure (full sun, part shade, or full shade), wind exposure, and accessibility of water. (Xeric and native plants require regular watering in their first year.) Organic amendments are not indicated for this type of garden, but drainage can be improved by tilling in pea gravel.
• How much time are you willing to spend to establish and maintain the plantings? (Native and xeric plants are easy-care after their first season, but tasks like weeding and pest and disease control are forever.)
• David Salman of High Country Gardens recently posted a great article incorporating basic design pointers with suggestions for the xeric garden: 9 Tips for Professional-Looking Garden Design. 
• If you’re converting a yard from turf to xeric/native plantings, consult the Extension fact sheet Xeriscaping: Retrofit Your Yard for ideas on how to proceed and suggestions for xeric substitutes for popular plants.

Swallowtail on Jupiter’s Beard, City of Greeley Xeriscape Garden (Flickr)

Think About the Contents of this Specific Garden

• What varieties of plants do you like, and what does well in your area? Take a look at neighbors’ yards, demonstration gardens, and local-nursery offerings to find your preferences. 

• Look at the ‘Native Plants’ section of this list of CSU Extension fact sheets to read and download information on Colorado’s native trees, shrubs, perennials, and grasses.
• Links to the native plant guides for five regions in Colorado published by the Colorado Native Plant Society are available on this page.
• For xeric plant suggestions, consult the page listing xeric demonstration garden plants on the Adams County Extension website. Most nurseries here have caught on to xeriscape principles and have added many xeric plants to their stock, so spend some time prowling their aisles.
• Will you plant for a lush look, which may entail buying many plants and a great deal of work, or space plants widely and use groundcovers or mulch to fill in between them? (This might be a good strategy for the first-year garden.)
• What are the space requirements for the selected plants? Remember that perennials, trees, and shrubs will take more than one season to attain their mature sizes. Take the mature sizes listed for xeric and Colorado native plants VERY seriously; these plants like our short growing season and will grow to the sizes shown much more readily than plants that originated in less rugged climates and longer growing seasons than ours.
• What are the cultivation requirements for the plants? Group plants that have similar water, soil, and sun requirements together – many Colorado natives have adapted over the centuries to our clay soils and might falter in the sharply-draining soil loved by xeric varieties. Check the tag for water needs or research the plant to be sure.
• Be prepared to mulch; what is used is a personal choice, but DO NOT use landscape fabric. Groundcovers are a good living mulch if you like them.
• Consider how the garden will look throughout the year. Plant tall grasses and evergreen shrubs and groundcovers and leave stems and seedheads on perennials for winter interest (and to feed and shelter wildlife in colder months). Look for plants that fruit and/or display colorful fall foliage.

That’s the skinny (or most of it) on xeric and Colorado plants. Remember to take your time with selection and establishment, and to contact your local Extension office with any questions. 

Gardening in Colorado’s Warmer, Drier Climate

By: Molly Gaines
CSU Extension-Denver Master Gardener since 2019

As we begin 2022, Denver just had its first big snow of the season. It finally comes amid an extreme drought, blamed largely on climate change, and the day after the massive Marshall fire on Dec. 30, the most destructive fire in Colorado history.

As our climate warms, drought worsens and moisture and weather patterns become more unpredictable, it is greatly impacting how gardeners in Denver and beyond approach what they grow and how they garden.

Lucky for us, as people who are passionate about plants and soil, we can help create climate resiliency through our home and community gardening efforts. It’s one reason I’m so drawn to gardening. During these wildly unpredictable times, it feels like something I can do to have a positive short- and long-term impact on my neighborhood and community.

Stacks of books could be written on this topic, but I’d like to offer a few ideas on how we as gardeners can work with our changing climate to grow successfully and in ways that help create higher-quality living environments in the face of more extreme weather.

1) Build up the soil.

Whether you’re planting directly in the ground or in containers, focus on building healthy soil. The healthier the soil, the stronger plants will grow and, if you’re growing food, the more nutrient-dense that food will be. Healthy soil, packed with microorganisms and earthworms, is also vital to sequestering carbon.

Plants grown in healthy soil are more pest and disease resistant and overall have better outcomes. For information on how to build healthy soil in your gardens, see this PlantTalk Colorado article, “Maintaining Healthy Soils”.

Building healthy soil with compost and other amendments creates nutrient-density and plant resilience. Photo by Molly Gaines

2) Plant trees — and be sure to water them adequately.

A New York Times headline on this topic last summer caught my eye, “What Technology Could Reduce Heat Deaths? Trees” (July 3, 2021, by Catrin Einhorn). Scientists have found that trees can lower air temperature in city neighborhoods 10 degrees, reduce electricity demand for air conditioning, save money and emissions and help avoid massive power failures during heat waves, according to the article.

For more on proper tree planting, particularly in urban environments, see a post I wrote last fall, “Fall Tree Planting Considerations and Tips.”

In Denver, particularly during extended periods with no to little moisture, year-round watering is critical. Most homeowners don’t water their trees enough, which leads to poor tree health, wind damage and premature death. The general rule of thumb is 10 gallons of water for each diameter inch of the tree’s trunk.

For additional winter watering information, see our recent post “Winter Watering.”

Healthy urban trees in their fall glory. Photo by Molly Gaines

3) Use native, drought resistant perennials for landscaping.

Plants that are native to Colorado are already naturally adapted to our growing conditions. They will require less water and fertilizer and be more resistant to pests and disease.

As water becomes scarcer, minimizing water usage for landscaping will become more critical. Landscaping our yards and gardens with native plants can lessen our overall usage of water.

4) Grow a vegetable garden.

Planting a garden and growing some of your own food for friends and neighbors is a wonderful way to lessen your impact on the environment. It helps cut down on carbon emissions, reducing the amount of food that travels on trucks for miles to the grocery store.

When food is grown with minimal chemical inputs, it also reduces toxins in our environment and increases the number of pollinators around our homes and communities, providing them safe habit and more balance in our ecosystem.

A bounty of vegetables grown in a modestly sized home garden. Photo by Molly Gaines

As gardeners, particularly in Colorado, we are used to planning, tending, working with nature and being flexible in the midst of adverse weather. Our warming climate and more extreme weather events will make these skills more imperative than ever before.

Keeping these ideas top-of-mind will help us all grow successfully, while also experiencing the joy and respite our gardens bring during these challenging times.