Colorado Gardening Calendar for April 2024

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

Last week’s snow covering forsythia starting to bloom. Photo: Molly Gaines

Signs of spring are everywhere in Denver. Daffodils, crocus and other spring flowers in full bloom one day; covered in ice and snow the next. Oh, to be a gardener at 5,280 feet!

While it’s too early to spend a lot of time planting, it’s a perfect time to prepare your soil, garden beds, tools, pots and lawn for the 2024 growing season. Below are a few gardening activities to consider before Mother’s Day, May 12 (around the safe zone from hard frosts) for planting most plants, flowers and vegetables.

Crocus are always a welcome first sign of springtime. Photo: Molly Gaines

As you plan your garden, it’s worth noting that some of the Denver metro is in a new gardening zone. Last November, the USDA announced updates to its “Plant Hardiness Zone Map,” updating this go-to tool for gardeners for the first time since 2012. The new map, which can be found here, places parts of Denver in Zone 6a rather than 5b. Zone numbers reflect the average extreme minimum temperatures and help determine what plants will thrive in each zone.  Higher numbers equal incrementally warmer low temperatures. For background about how to use this map as a planting guide, visit this helpful article from the National Gardening Association’s learning library.    

New USDA Plant Hariness Zone Map now places parts of Denver in Zone 6A. Credit: USDA

Vegetable Garden

• Clear remaining debris. Pull emerging weeds.
• When the soil is dry, add a fresh 2-3-inch layer of compost to your beds. This supports soil health and plant vigor. Gently work compost into the top layer of your existing soil with your hands, a trowel or a cultivator. Let rest a few weeks before planting.
• Plant frost-tolerant spring plantings, such as peas, spinach, arugula, radishes, Swiss chard, etc.
• Start indoor seeds for warm-weather vegetables such as tomatoes, peppers, squash, melons, etc.
• Reference this Vegetable Planting Guide to plan what you will plant when.

Trees & Shrubs

• The snowpack is solid Colorado-wide this year, well above 100 percent. This includes Denver. That said, if this month is dry, be sure to water your trees and shrubs.
• Early this month, prune deciduous trees, conifers and summer-blooming shrubs.
• Later in April into mid-May, prune rose bushes. For details on exactly how, why and when to do this, visit here.  This is weather dependent so watch for low temperatures and delay if a cold snap is predicted.
• Remove broken branches from trees and clear dead leaves and decayed fruit from the base.
• If you’re looking to plant a new tree, consider the Park People’s annual fruit and yard tree sale that begins April 20. Trees range from $50 to $80, and sales support the Denver Digs program. More details can be found here.  

Lawn Care

• Prep your mower, sharpening the blade as necessary and conducting other maintenance. Lawn mower blades should be sharpened at least once per season.
• If you use a pre-emergent weed product, apply in early April. For more details about how to use, visit here.
• Fertilize as desired, reading labels for proper application. Keep in mind that fall is the most important time for lawn fertilization. Applying only in the spring can mean excessive top growth and shallow root systems.

Perennial Beds

• Cut back perennial plants if this wasn’t done last fall, leaving 3 inches of the plant above the soil.
• Similar to your vegetable garden, the soil in these beds will also benefit greatly from compost, with the exception of native plants which generally prefer unamended soil.
• Pull emerging weeds now. Stay on top of them from the start.
• Divide overgrown perennials such as chives, sedum, grasses, phlox, daisies, hosta, etc. This will lead to healthier plants and better growth.

Other April Gardening Thoughts

• Assess garden supplies. Purchase or plan to borrow anything needed. Sterilize and sharpen garden tools.
• Empty any pots or containers still holding last year’s dead plantings. Clean and disinfect them to prevent disease in new plantings.

These pots need to be cleared of last year’s plantings, disinfected and filled with new soil for plantings. Photo: Molly Gaines

• Denver Water recommends waiting to turn on your irrigation until after the last freeze, typically in early May. Hand water until then.
• Sow wildflower and pollinator seed mixes.
• Prepare for frost, hail and other bad weather. Have sheets of plastic, old bedsheets and five-gallon buckets in easy reach for late-season snow or spring and summer hail. Remember the hailstorm that hit Denver late June last season?

Sad peas in a bed covered with hail. June 29, 2023. Photo: Molly Gaines

Springtime in Denver is special. I love watching new life slowly unveil itself. It’s a time full of promise, new beginnings and high anticipation of the color, flavor and textures around the corner. The more prepared you are in April, the more enjoyable your summer gardening season will be.

As always, if you have questions about plants, planting and any other gardening and yard related topics, visit the CSU Extension Yard and Garden website for tips.

Reducing Garden Maintenance

By Margerie Hicks, CSU Extension – Denver Master Gardener since 2010

Except for those with a live-in gardener, we all want beautiful, lush gardens with little or no fuss and minimal effort. To achieve this, we need to plan for garden features and types of plants that eliminate some of the work. Here are three approaches to consider.

Apply Mulch to Control Weeds

If I were a poet, I would write an ode to mulch’s many useful properties. A layer of about three inches in beds will reduce maintenance by blocking out light and inhibiting weed germination. It also retains moisture to reduce watering needs.

Shredded bark mulch stays in place on this sloping garden bed. Photo by Margerie Hicks

There are various sizes, colors, and types of mulch available, depending on the purpose, location, and your personal preference. This CSU Extension fact sheet lists many varieties of mulch, along with the advantages and disadvantages of each. Some of the most common are:

• Wood/bark chips: Functional for many purposes.
• Shredded bark: Fibrous, coarse texture mulch made from finely shredded bark of redwood and western red cedar trees. It is useful on slopes as it reduces soil erosion and doesn’t wash away.
• Grass clippings: Functional in vegetable gardens where wood and bark mulches are not advised.
• Pea gravel: Besides weed control, it looks great in succulent and native plant gardens. It increases water infiltration and can improve the growth of perennials, especially in water-saving gardens.

Install Ground Covers 

Many ground covers form a thick layer that discourages weed growth. Over time the plants will spread and thicken for an increasingly better weed barrier. The many colors, textures, and sizes are aesthetically pleasing, too. This extensive list of ground covers is arranged by sun vs. shade and size of area to be covered and this list offers suggestions for shading loving, drought tolerant groundcovers. 

These groundcovers, described below, will spread to cover most of the bed’s surface in a few years. Photo by Margerie Hicks

Plants in the photo above:

• Hens and chicks form tight clusters of succulent rosettes; may have red and green hues.
• Ice plant ‘firespinner’ has succulent foliage covered with bi-colored orange and fuchsia blooms. Ice plants are available in many colors.
• Thyme ‘pink chintz’ is low growing with purplish-pink flowers.
• Dianthus ‘maiden pink’ produces single pink flowers above narrow foliage. Many dianthus varieties have the same thick weed barrier effect.

Others that combine weed barrier function and beauty:

• Turkish veronica is a low growing carpet-like ground cover with a profusion of tiny purple blooms.
• Sedum ‘Angelina’ has pleasing light green foliage in early summer; turns orange later in the season and into winter.

Eliminate or Contain Plants That Spread Rapidly

Many plants in this category may be plants you like, so you will have to weigh the advantage vs. the effort to control them. Just as mulch deters weed growth, it can also deter the unwelcome spread of some of these plants.

Russian sage whose spread is out of control. Photo by Margerie Hicks

Examples of plants that can become invasive:

• Mint gets out of hand quickly. Grow it in a pot that is at least 12 inches wide and deep to contain spread.
• Bamboo is a super spreader. Select ‘clump-forming’ varieties, which are usually less invasive than ‘running’ types. Create barriers if necessary or consider planting it in large containers and keep their size in check by removing unwanted new growth as soon as you spot it.
• Russian sage is a member of the mint family, spreads by runners and needs to be monitored to keep it out of places where you don’t want it. Pull up suckers in the early spring and divide the plants every four to six years to refresh them.
• Lamb’s ear can quickly overtake an area. If you like the soft silvery foliage, silver sage is an excellent substitute.
• Quaking aspen trees readily send out new plants from the root system. To grow a single quaking aspen as a specimen plant or shade tree, you must continually remove any new plants from the root system to avoid growing unwanted trees. Aspens are also prone to disease at the metro area’s elevation.

Many other plants could be included in this invasive category, depending on personal preferences. In fact, it is often said that a weed is any plant that is unwanted in a certain location. 

After you have accomplished some of these measures, be sure to appreciate your newfound time to spend on other gardening tasks or just sit back, sip some lemonade, and watch your garden grow.

Dealing with Winter Storm Damage to Trees and Shrubs

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

Photo credit: Pixabay.com

During mild weather, we relax and admire our gorgeous lilacs and viburnums, fertile fruits, and long-lived majestic street trees. With the coming of the colder months, however, we become aware that these lovely friends are susceptible to damage and even death from sleet, high winds, and heavy wet snow. The effects of this weather are a constant concern on the Front Range, but with a little forethought and planning, they can be mitigated (if never eliminated). 

Effectively dealing with storm damage requires planning that begins when a gardener is considering installing trees and shrubs. (Minnesota Extension offers some great information on dealing with tree damage based on this principle.) However, as most readers of this blog are probably here seeking advice after a catastrophe, let’s do some time-traveling and begin with should be done (and not done) immediately following a storm and conclude with some hints for encouraging plant survival in advance of nasty weather.

This post features the highlights of emergency tree and shrub care; review the article ‘Caring for Storm-Damaged Trees’ from the Colorado State Forestry Service for more thorough guidance.

• During a heavy snowfall, brave the flakes to gently shake accumulated snow off tree and shrub branches with a broom. Lift each branch from the bottom instead of poking or shaking it. (Be prepared to do this more than once.)
• Before going out, look at the yard and street: are power lines down, are there dangling tree branches threatening to drop, or is debris or ice covering the turf or the walks? Any one of these can present a hazard to gardeners working outside. Above all, assume that any power line lying on the ground is live. 
• Examine the damage: look for leaning, broken, or uprooted trees and shrubs. Determine if there are holes and cracks in bark, trunks, or roots. Note the state of the crown (branches and foliage) of each tree; loss of more than 50% of the crown may require tree removal. 
• Leave ice coating the branches alone; it will melt as soon as temperatures rise above freezing.
• Damaged bark can be removed back to the point where healthy bark appears.
• Don’t top a damaged tree; you’ll render it weaker and more susceptible to disease.
• Avoid painting holes, wounds, or pruning cuts; the plants will seal and heal by themselves.
• Small tree branches can be removed by the gardener (see the fact sheet ‘Pruning Shade Trees’ linked below for details) but allow an arborist to remove large branches. 
• Leaning shrubs and small trees can be moved back into position, staked, and mulched.
• Wait until new growth appears to fertilize.
• Inevitably, friendly visitors bearing chainsaws will appear, offering to repair your tree and shrub damage “for less than those big companies.” These are the horticultural equivalents of gypsy roofers who show up after hailstorms. They are usually untrained and not covered by workers’ compensation or liability insurance.

Now, let’s examine how we can minimize storm losses with some deterrence.

Mitigating plant damage begins with asking what genera, species, and varieties of trees and shrubs display less vulnerability and more resilience in the erratic Colorado climate. Luckily, the ready answer is (drum roll……) native and adaptive plants. Plants that have evolved in montane, submontane, or plains environments will rebound from weather damage much more quickly and thoroughly that those imported from dissimilar growing conditions. Plan for resilience by selecting trees and shrubs recommended in these resources: 

• Native Shrubs for Colorado Landscapes
• Native Trees for Colorado Landscapes
• Front Range Tree Recommendation List
• Tree Selection: Right Plant, Right Place
• Plant Select

Once plants have been selected, practice proper siting and planting. Again, we’re assisted by Extension and Plant Talk resources:

• Preparing the Planting Site
• Tree Placement: Right Plant, Right Place
• Planting Trees and Shrubs

Proper cultivation and integrated pest management (IPM) are indispensable to plant health, as outlined in these publications:

• IPM and Plant Health Care
• When to Fertilize
• Watering
• Pruning Shrubs
• Pruning Shade Trees

For information on specific plants, diseases, and pests, review the resources on subjects from “abnormal and distorted plant growth” to “Zimmerman pine moth” included in the Extension page Online Gardening Publications (Trees and Shrubs). 

Fans of Gardener’s Supply Company should check out the great discussion of winter damage prevention on their website.

We hope that this is helpful in the present emergency and beyond – but, as always, Denver County Extension is eager to help with all problems and concerns!

Colorado Garden Calendar – December 2022

Photo: Jodi Torpey

By Linda McDonnell, CSU Extension – Denver Master Gardener since 2013

Gardening slows down in December but doesn’t stop completely. There’s still time to finish some chores from our November list, so be sure to revisit it. For the next few months, prioritize winter watering during dry spells to ensure healthy plants next year.

December’s also a great time to enjoy indoor plants, appreciate nature’s seasonal beauty, and start thinking about next year’s garden.

Here’s a run-down of tasks and activities for December.

Trees, Shrubs, and Perennials

• Winter watering is essential to long-term plant health – make it a point to water during four-week dry stretches. To ensure proper absorption, water early in the day when temperatures are above forty degrees. This post offers excellent advice on when, why, and how much to water – and photos of the impact of too little moisture.
• To help with moisture retention, replenish mulch in areas that have gotten thin.
• Shake snow from bent tree limbs and branches to avoid breakage and lightly prune any broken limbs to avoid further damage.

Compost

• Continue adding green and brown materials to your compost bin. Since decomposition is slower in cold temperatures, break your materials into smaller pieces to speed up the process. The University of New Hampshire offers more winter composting tips here.

Thanksgiving cactus approaching its fourth decade & going strong. Photo: Linda McDonnell

Houseplants

• Winter is the dormant season for non-blooming indoor plants. Reduce watering, stop fertilizing, and keep them away from drafts for the next few months.
• Increase humidity around your plants. Ignore popular advice to mist with a spray bottle – to make an impact you’d need to mist for hours on end! Instead, group plants together on a pebble-lined tray and add water to just below the top of the pebbles.
• Check regularly for pests such as mealy bugs and spider mites. If present, treat and quarantine the infected plant. Find remedies here.
• ‘Tis the season for holiday plants and live Christmas trees. Here are some helpful links to keep them at their best: Keeping the Ho Ho Ho in Holiday Plants, Tips for Caring for Your Christmas Tree, A Year in the Life of an Amaryllis, and Christmas Cactus Care.

Celebrate, Inspire, and Explore

• The winter solstice arrives on December 21^st. In the Northern Hemisphere, it marks the day when the sun is at its lowest height at noon as well as the shortest day of the year. Starting the next day, we’ll gain about two minutes of daylight daily till June 21^st. Yippee!
• Share your enthusiasm for gardening with a child – find a few activities here or wander the library aisles to find an inspiring book on plants or nature.
• Check out 2023 seed introductions from your favorite growers. It’s time to start scheming and dreaming about next year’s garden.

As always, CSU is available to help with gardening advice at the CSU Extension Yard and Garden website. We hope you’ll visit often.

We’ll be back in two weeks with our last post of the year. Until then, enjoy all the season brings.

Planning a Dry Shade Garden: Making Lemonade with Dusty Strawberries

Lori Williams, CSU Extension – Denver Master Gardener Since 2016

Bergenia cordifolia is well-suited for dry shade. Photo: Flickr

This is a dry shade garden story of happy accidents, fortunate timing due to 100+ degree temps, and purely unexpected research wrapped in a beautiful day at Denver Botanic Gardens Chatfield Farms.

After more seasons than I’d like to admit there is part of my yard that has silently been waiting for attention for many years. It’s fully dry shade, anchored with a lovely oak tree that has reliably made this space look pretty good despite lacking design and plantings, and receiving water only for the tree’s sake. Lackluster turf is more grayish than green and sparse to say the least. Hello Sad Spot, it’s finally time for your makeover.

With these hot temps I’ve retreated inside and have been pouring over xeric plant guides, watched the uber helpful presentation ‘Dry Shade Planning and Planting’ by Amy Lentz of Boulder County Extension, and investigated various garden designs and plant suggestions offered by the fine folks at Plant Select, Denver Water, and our very own CSU Extension.

The added bonus was finding myself immersed in a treasure trove of design and plant specimens at Denver Botanical Gardens Chatfield Farms a few weeks ago. Dry shade garden inspiration abounds!

A clear pattern of attack is laid out for not only dry shade but any new garden spot:

• plan ahead
• improve the soil
• limit turf
• efficient irrigation
• select plants
• mulch
• maintain

Plan ahead…hmmm…plan ahead….me? Oh but it’s a heat wave and due to travel plans and work obligations I’m doing research for a garden spot that I won’t be able to implement or plant until early fall. That sounds like I’m planning ahead!

Step one? Check! I even have time to have my soil tested.  And I’ll have time to actually amend the soil. This is going great! Look at me, planning ahead. It’s a new and different approach but I think I like it.

Next, I literally trip over one of the oak’s roots while collecting dusty soil samples and find myself looking at something that wasn’t half scorched turf but rather a mixture of barren and fruiting strawberries with yellow and pink blossoms. They were as dusty as the grass, but they’ve voluntarily planted themselves in this neglected space. Brazen little things! Congratulations, guys – you’ve just won the ‘Right Plant, Right Place’ award. Based on your gumption I decided on the spot that strawberries are the ground cover of choice.

I’ve spent time on cool mornings removing the patchy grass with my hori hori, providing more space for the strawberry tendrils to reach out and set roots. It’s delightful to see them take hold.

When Mother Nature gives you strawberries, make a strawberry lawn. Photos: Lori Williams

Thankfully, we have a sprinkler system, but the heads are all wrong (have been forever) for this area and I’ve been hose watering this dry shade zone instead for years. Once I fully determine the plants’ placement and they are well established, soaker hoses will replace the sprinkler heads to water the new guys more effectively. I’ll stick to the garden hose with my ancient frog eyed sprinkler during the establishment phase.

Photo: Lori Williams

One of my best-ever gifts from Mom was Denver Water’s series of xeriscape books.  They developed the whole xeric gardening concept to begin with, so Colorado-proud of them. Highly recommended reading!

Mulch selection is still a bit up in the air, but I am a diehard fan and believer. I feel like mulch is kind of the reward topper-offer at the end of newly planted garden spaces. It really makes things pop and look fully finished while stealthily helping manage weeds and providing moisture retention in the garden. Win Win Win!

As mentioned earlier, I happily found myself at Denver Botanic Gardens Chatfield Farm recently. I was expecting a lovely visit of course, involving a great stroll while surrounded by beauty. Perfect! Embarrassingly, I think I’ve only been to the arboretum for holiday lights during the winter.

This visit turned into Christmas in July as I opened my eyes and mind and phone camera – a dry shade plant selection opportunity extraordinaire! Lenten rose? Bergenia cordifolia? Siberian Bugloss? Now I only need to ‘weed’ through approximately 47 plants to select the 3-5 for my make over garden. But as I’m planning ahead, ahem, I have time.

Additional sources:

Kinds of Shade

Zero Water Gardening

Dry Shade Solutions

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

Pollinator-Friendly Fall Garden Cleanup

By Jessica Harvey, CSU Extension – Denver Master Gardener since 2020

As we wrap up the season and put our gardens to bed, there are a number of ways we can help provide habitat for our pollinators in the process. Many pollinators will nest in the hollow of stems or wood. Others will use things like leaves, mud, plant hairs, and resin to build their nests for the winter. Rather than chopping everything down and clearing out the remaining debris, let’s consider whether any of it may be used by a pollinator this winter, or even next spring.

For those pollinators that like to nest within hollow stems, consider deadheading rather than chopping those stems down to their base. Stems can range 8 to 24 inches long, from both flowers and grasses alike, to be of use for cavity nesters. A nest within a hollow stem will typically house eggs, a food source and a natural plug of some kind that can be specific to the type of pollinator that are nesting within. A couple of great examples are leaf cutter bees (Megachile) and Mason bees (Osmia and/or Hoplitis). 

Remember to allow those same stems to decay and fall on their own in the spring as you don’t want to remove them until after the young have emerged for the season. If you grow raspberries doing so is easy, since you may need those prime canes for next year’s production.

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  Raspberry canes in the Spring. Photo: Jessica Harvey
  

Check out this great handout with diagrams highlighting some of the different cavity nesters from University of Minnesota Extension and their Bee Lab. 

Not to be forgotten, consider pollinators that are ground nesters as well. It’s important to leave some bare earth for these guys to burrow into for their nests. If you have pets or children, you may consider a place out of the way within your garden.

Another excellent resource is CSU Fact Sheet No 5.615 Attracting Native Bees to your Landscape which provides more information on different nesting materials and ways you can provide additional habitat specifically for native bees. 

Just like any other living thing, the main concerns for pollinators are food, water, and shelter. As we clean up and leave some debris intact for them as shelter, it’s also important to try to provide some clean water. It may be hard to do this during the winter but consider adding a tray with pebbles near your hollow stems or bare ground, and keep it topped off during the fall and spring. No need to buy anything specifically marketed as such, it can be as simple as the drip tray from a container you aren’t using.

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  Drip tray in community garden. Photo: Jessica Harvey

As we wrap up for the season and begin planning for the next, also consider whether you have a year-round source of both pollen and/or nectar within your garden to encourage a strong pollinator population. Ground covers, winter blooming crocus and early blooming grape hyacinths (Muscari) will help to bridge some of the gaps.

CSU Factsheet 5.616 Creating Pollinator Habitat gives a glimpse of all the things to consider as you plan your garden as a pollinator habitat, including some plants to consider for all season provisions.

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It’s important to remember our pollinators not just during the peak of the season when we need them for our flower, fruit, or vegetable production. They provide so much for us and we need to try and return the favor wherever we can. 

May Gardening Calendar of Tasks & To Do’s

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

Happy May Day, gardeners! We’re getting closer to putting plants in the ground every day, woo! And we can all get even closer today (May 1) by ordering online for the Denver Master Gardener’s Plant Sale.

Beyond the fun of shopping the DMG Plant Sale, May is a busy and exciting time of year. There is a lot we can do to get ready for jumping into 2021’s growing season.

Survey your garden, as you clean things up.

• Note what’s coming up, what pooped out, what needs transplanted to the right place and what are the right plants for bare spots.
• Straighten the trellis, spray down the patio furniture and clean and disinfect the garden tools and containers that you’ll be using.

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  Gloves and tools by Lori Williams

Healthy Soil

Soil is the foundation of gardening success, so give your established, new garden beds and future spots for plantings the best gift ever!

• If you haven’t had a soil test done for your garden, go for it. It’s interesting, informative and guides your soil amending.
• A recent Denver Master Gardeners blog post details the best practices and the importance of soil health in our gardens.

Compost

• Harvest this rich organic matter from your bin, pile, or barrel and treat your garden. Gather it into a wheelbarrow or onto a tarp so you can easily move it around your yard to top dress garden beds and around plants throughout your garden. 
• Creating and maintaining compost is well worth the effort.

Trees

• Inspect your trees for any damage from Colorado’s weighty snowfalls and gusty winds. If an arborist is necessary, call to get on their schedule, they get busy fast.
• Trees are beautiful and beneficial in so many ways. Maintaining them is central to their health and longevity. CSU Garden Notes 650-659 will provide you with essential tree care information.

Shrubs & Vines

• May is prime time for pruning and shaping shrubs, vines and even roses.
• Take time to prune and fertilize your roses early this month. They’ll love the attention and will reward you with blooms and color for months.

Perennials

• After you clear beds of die-back plant debris, show your perennials some TLC to make their annual debut better.

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  Hellebore is a shade loving, long-standing perennial that offers early season magic. Photo by Lori Williams

Vegetables

• When outdoor temps are holding at a minimum of 40°F, hardy, cool season vegetable seeds like peas, lettuce, kale, and spinach can be direct sown into the prepped bed
• More tender/warm season crops need nighttime temps to be reliably at a minimum of 50°F. Patience is truly a virtue in planting things like tomatoes, peppers, and eggplants.
• Hardening off or acclimating delicate bedding plants prior to planting them outside is essential. Start by putting plants outdoors in a protected area for a few hours each day and then bring them inside. Gradually increase the amount of time outside over the next week to 10 days until they can be left out overnight.

Lawns

• Lawns thrive with mechanical aeration that pulls soil plugs 2-4 inches apart.    
• The CSU Turfgrass Program provides complete lawn care tips throughout the season.

Irrigation systems

• Schedule to turn on your irrigation system to test the coverage patterns and actual amount of water reaching your garden.
• It’s worth time and money to water wisely, minimize overspray and help Colorado conserve as much water as possible.
• Program your system responsibly, Denver Water offers a watering guide by month.

Annuals

• Annuals are the color bombs and mainstays of many a patio pot and garden bed. Love them SO much and we enjoy them in not only our yards but all over town. Shop till you drop at your local nurseries, start them by seed, and plant them with abandon!
• Use the CSU Annual Plant Trials to find the top performers for your garden.

Mulch

• Mulch is just like what we say about kindness: it’s (almost) free, spread it everywhere! Watch for more on mulch up next on the next Denver Master Gardener blog.

Happy gardening in May, enjoy!

Visit the CSU Extension Yard and Garden website for more gardening tips.

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  The tulip’s tenacity defies spring snow and frigid temps, absolutely joyful. Photo by Lori Williams

No More Buds? Turn to Earbuds.

By this time in the year, I’m at the point of good riddance! with the weeds and careful tending (shout out to this cold spell for sealing the deal). Pretty much everything is done and put to bed. I then spend the next two weeks really dialing into my houseplant game before I get bored and start Spring dreaming. My Fall break from the garden is short-lived so I start listening to old episodes of now-defunct podcast series and dream with new ones.  Here are a few of my favs:

Gardenerd Tip of The Week

Gardenerd.com is the ultimate resource for garden nerds. We provide organic gardening information whenever you need it, helping you turn land, public space, and containers into a more satisfying and productive garden that is capable of producing better-tasting and healthier food.

https://gardenerd.com/

My thoughts: The host lives in LA, so this one is great for winter listening as we get chillier, I love hearing about the warmth of Southern California and what’s coming into season. Interviews with other experts and educators in the horticulture field discussing plants, but also cultivating grains, discussing bees, and seeds. Each episode ends with the guest’s own tips, many of which are news to me and have been incorporated into my own practices. 

On the Ledge

I’m Jane Perrone, and I’ve been growing houseplants since I was a child, caring for cacti in my bedroom and growing a grapefruit from seed; filling a fishtank full of fittonias and bringing African violets back from the dead.

https://www.janeperrone.com/on-the-ledge

Houseplants, if new to the podcast start here for an overview, and guidance.

Jane is a freelance journalist and presenter on gardening topics. Her podcast has a ton of tips for beginners, and more advanced info for longtime houseplant lovers, as well as interviews with other plant experts. The website is also useful to explore the content of an episode if you aren’t able to listen. I could spend an entire morning traveling in and out of the archives. 

My thoughts: As the growing season comes to a close, my indoors watering schedule starts wobbling between what the plants need and my summer habits of watering too many times per week–welcome back,  fungus gnats! Here’s an entire episode on them

Plant Daddy Podcast

We aim to create a listener community around houseplants, to learn things, teach things, share conversations with experts, professionals in the horticulture industry, and amateur hobbyists like ourselves. We also want to bring the conversation beyond plants, since anybody with leaf babies has a multitude of intersectional identities. We, ourselves, are a couple gay guys living in Seattle, Washington, with a passion for gardening and houseplants. A lot of our friends are the same, though each of us has a different connection, interest, and set of skills in this hobby, demonstrating a small amount of the diversity we want to highlight among plant enthusiasts.

https://plantdaddypodcast.com/

My thoughts: Plants are visual, podcasts are auditory- episodic overviews with links to viewable content available on their website. Are you also seeing Staghorn Ferns everywhere? They have an entire episode (photos included!) on the fern and how to properly mount it for that vegan taxiderm look. Matthew and Stephen are self-identified hobbyists with a passion for plants all the way down to the Latin–it’s impressive.

Epic Gardening

The Epic Gardening podcast…where your gardening questions are answered daily! The goal of this podcast is to give you a little boost of gardening wisdom in under 10 minutes a day. I cover a wide range of topics, from pest prevention, to hydroponics, to plant care guides…as long as it has something to do with gardening, I’ll talk about it on the show!

https://www.epicgardening.com/

My thoughts: The Netflix-episode-when-you-just-don’t-feel-like-a-movie kind of podcast. Addresses the best varietals, composting, soil pH, and troubleshooting some common issues in the garden. With daily episodes archived back to December 2018, there is a quickly digested thought for some of your own curiosities. The website is also a wealth of knowledge. 

Eatweeds Podcast: For People Who Love Plants

Eatweeds: An audio journey through the wonderful wild world of plants. Episodes cover modern and ancient ways wild plants have been used in human culture as food, medicine and utilitarian uses.

http://eatweeds.libsyn.com/

My thoughts: most recent episode (and appropriately timed!)  On edible acorns. My fav topics include foraging and wild yeast fermentation; and when I really start missing the Pacific Northwest, The Wild and Wonderful World of Fungi sends me back to a misty forest wander politely decorated by les champignons. Posting of this pod is sporadic–only 25 episodes since 2014.

You Bet Your Garden

(no longer on air, but archives available)

 

You Bet Your Garden® was a weekly radio show and podcast produced at WHYY through September, 2018. The show’s archive is available online. It was a weekly syndicated radio show, with lots of call-ins. This weekly call-in program offers ‘fiercely organic’ advice to gardeners far and wide.

https://www.wlvt.org/television/you-bet-your-garden/

My thoughts: Host, Mike McGrath, spends much of the show taking calls and troubleshooting, reminiscent of another public radio behemoth with Click and Clack, the Tappet brothers. McGrath incorporates a lifetime of organic gardening tips with humor. McGrath features one tip to find a local “rent a goat place” (no joke) to get goats to eat the most troublesome weeds to a concerned caller considering setting much of her yard on fire.

Cultivating Place: Conversations on Natural History and the Human Impulse to Garden

Jennifer Jewell, the founder of Jewellgarden and Cultivating Place, achieves this mission through her writing, photographs, exhibits about and advocacy for gardens & natural history and through her weekly public radio program and podcast Cultivating Place: Conversations on Natural History and the Human Impulse to Garden, on gardens as integral to our natural and cultural literacy.

https://www.cultivatingplace.com/

My thoughts: sort of like On Being, but for gardening.

A fav episode:

If you aren’t so sure about this podcast thing, and just want a place to start, start here.

Do you really need a brain to sense the world around you? To remember? Or even learn? Well, it depends on who you ask. Jad and Robert, they are split on this one. Today, Robert drags Jad along on a parade for the surprising feats of brainless plants. Along with a home-inspection duo, a science writer, and some enterprising scientists at Princeton University, we dig into the work of evolutionary ecologist Monica Gagliano, who turns our brain-centered worldview on its head through a series of clever experiments that show plants doing things we never would’ve imagined. Can Robert get Jad to join the march?

https://www.wnycstudios.org/podcasts/radiolab/articles/smarty-plants

The Weather Outside is About to Change

October is the month the garden takes its final breath, the first frost arrives (this week!) and pumpkin-everything surrounds us. We’ll still have some beautiful fall days, but there’s no denying it, the growing season is coming to a close. So with that in mind, here’s a round up of helpful information for the days, weeks and months ahead.

• Sometimes working less is working smarter – find tips for putting the garden to bed here and here.

• Why am I always late scheduling this? Instructions for winterizing sprinkler systems here. (It’s helpful to read even if you leave this task to others.)

• Have your houseplants been living outdoors? With temperatures about to plunge, it’s time that vacation comes to an end. Some good reminders on how to help them transition to lower light can be found here. 

• My Chanticleer Pear tree (Pyrus calleryana ) is soooo prone to storm damage in both the fall and the spring – this CSU PlantTalk article provides excellent information on snow-load damage and pruning of herbaceous plants.

• If you have upright junipers, you know they are also prone to winter splitting. Here are some excellent tips on preventing structural damage, including a creative use for Christmas lights.

• And finally, be mindful of the winter moisture levels. “Your Yard is Thirsty” offers advice on winter watering of a variety of plants.

Written by Linda McDonnell, a Denver County Master Gardener

Image by Anne Hughes, a Denver County Master Gardener