Colorado Gardening Calendar for May 2024

By Valerie Podmore – CSU Extension-Denver Master Gardener since 2020

This is the month we’ve been waiting for! May is the best month for getting your plants from the Master Gardener Plant Sale on the 18^th and 19^th and planting them, with the caveat that anything can happen weather-wise, so be ready…remember 2 years ago?

Vegetable Garden

• This is the time to direct sow hardy, cool season vegetable seeds such as lettuce, kale, and spinach.
• Plant your (newly purchased!) veggies and herb plants when nighttime temperatures are consistently a minimum of 50 degrees, and make sure to protect them with cover when temps drop below 40 degrees. This includes tomatoes, peppers, and eggplants.
• Consider your planting location, i.e. Rotating your crops to prevent bacteria that might have infected plants last year from doing so again.
• Weeding is essential as much as possible, so let’s get on it!

Trees and Shrubs

• Just in case May ends up being sparse in the precipitation arena, don’t be afraid to bust out your hose and give your trees a good soaking, watering deeply once per week.
• This is also a good month to prune trees to remove any dead branches from needed but possibly damaging snowfall.
• Mulching is a great way of helping your tree retain water, just make sure to keep it between 3-4” deep and about 6” away from the trunks so it doesn’t hinder healthy root development and allows the plant to take up moisture.
• Prune summer blooming shrubs that bloom on new growth, such as roses before they begin to flower. Refrain from trimming shrubs that bloom on old growth such as lilacs until after they flower.
• This information sheet has great pruning information.

Lawn Care

• This is a great month to aerate the lawn to loosen up soil for better water absorption, as well as removing thatch (tight, brown, spongy, organic layer which can cause problems down the road in terms of lawn health) when it becomes too thick.
• After aerating is a wonderful time to overseed your lawn to regrow any bare spots which have developed over time.
• Watering is important for lawns as for other plants as this month heats up. Of course, if there’s rain or snow, hold off.
• Watering in the late evening or early morning helps retain more water as the weather tends to be cooler and more humid at these times.
• This is the month to treat your lawn for Japanese Beetle grubs. Use products like GrubGONE! which has been shown to do a great job of stopping this pest before it leaves your lawn and infests your plants.   

Perennial / Annual Flower Beds

• Continue cleaning out the garden, including spent flowers and cutting back foliage to help perennial plants direct their energy to growing.
• Look at possible locations where plants might not have performed as well as desired and where you can fill in or move existing plants.
• Waiting until late May to plant annuals will give them a chance to survive any crazy cold spells, although there are many that will do well in cool weather, such as petunias and pansies.
• This is also a great time to plant summer blooming bulbs!

May is such a great gardening month, let’s take advantage it and grow, grow, grow!

Visit the CSU Extension Yard and Garden website (https://extension.colostate.edu/topic-areas/yard-garden) for more gardening tips.

Colorado Gardening Calendar for March 2024

By: Valerie Podmore CSU Extension-Denver Master Gardener since 2020

Snowdrops popping up through the snow (photo by Pixabay)

Hey friends, remember when it was January, and we were all lamenting how it seemed to never end? And then February was unseasonably warm and short, but Punxsutawney Phil did tell us early spring!  Well, celebrations are in order because it’s MARCH!

This is one of the best months for watching new growth come up and reigniting that gardening bug. Of course, there are other, more “productive” tasks to perform as well, so mark your calendar to get these gardening to-do’s done in your yard and garden.

Vegetable Garden

Coming soon to a veggie garden near you! (photo by Pixabay)

So, my first attempt at veggie gardening was “fun,” but because I’m not super into cooking it may have stopped me from being more attentive to my sad plants. That’s ok, maybe I’ll stick to flowers instead. For those of you who are more dedicated than I, take a look at some tasks below and know that gardening in Colorado usually requires the fastest-growing, most weather-hardy vegetable varieties.

• Clean out debris and replenish soil in vegetable beds while we wait for our seeds to start.
• Starting seeds indoors in March is perfect for any vegetables that should be planted outdoors in early April. Here is a list of seed companies if you are thinking of starting your vegetables from scratch.
• This link from The Old Farmer’s Almanac has all the recommended indoor and outdoor planting dates for vegetables and herbs.
• Think about layouts for your raised beds (if that’s what you’re using). This pdf has a lot of helpful information.
• Since spring seems to be coming early, vegetable garden water conservation might be a good topic to study.

Trees and Shrubs

Early spring Forsythia bloom (photo by Pixabay)

• Late winter/early spring are ideal times to trim trees, as explained on this page by the Colorado Forest Service.
• Precipitation in late 2023 was sparse, so it’s always a good idea to remember good watering habits for our trees and shrubs.
• This interesting article explains tree root systems and how our soil health, moisture and compaction (or not) can affect these very important plants.

Lawn Care

To lawn or not to lawn is becoming a much-discussed subject, given higher temperatures and lower precipitation amounts. Historically, many homes have yards planted with Kentucky Blue Grass lawns, which need more water, mowing and fertilization. This might be a good time to consider replacing your lawn with more native grasses (if you want to keep a lawn) or other native plants.

• In conjunction with Denver and other counties’ water providers, Resource Central has a lawn removal program to assist with moving to more natives.
• This is a great article about what native lawns can be planted instead of that water-hungry bluegrass.
• For those who want to keep their lawns as is (no judgement here!), mid- to late-March is a great time for aerating and general tidying.

Perennial Flower Beds

When I first became interested in gardening, I was – like all of us, I’m sure ­– in love with plants that were different looking, showy, flowering and easy to grow in places like Alabama, but not Colorado. I’m finally learning my lesson that it really is about the principle of right plant, right place. In addition, having listened to and read books and articles about the benefits of planting natives in our landscapes, I am becoming more attentive to what plants I choose for my landscape. I look not only for beauty, but regeneration and restoration. I mean who wouldn’t want to be part of a national movement like Homegrown National Park?

• Since I’m on my native plant kick, here’s a plug for these Colorado native perennials that can really enhance our landscapes and make them more sustainable.
• This is also a great month to start clearing out old, dead growth – as long as the weather is warm enough – to make room for shoots popping out of the ground.
• This page gives great information on perennial gardening so you can have everything prepped when you’re ready to put actual plants in the ground.

Annual Flower Beds

• Even though you can plant annuals pretty much anytime, they MOSTLY like being planted after last frost (usually around May 10-15).
• This is a great time to look at cool-weather annuals like pansies.
• The annual CSU Flower Trials have tested and found flowers that are hardiest and grow best through the tough, Colorado life. Check it out!

Make sure to mark your calendar for the May Denver Master Gardener plant sale (May 18 & 19) and visit the CSU Extension Yard and Garden website (https://extension.colostate.edu/topic-areas/yard-garden) for more gardening tips.

Colorado Gardening Calendar for February 2024

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

Blue fescue grass poking through snow at Denver Botanic Gardens. Photo: Margerie Hicks

February is one of the best months to enjoy the interesting patterns, textures, and shapes that dried grasses and perennials form in contrast to the snow. It is also a time to read or otherwise educate yourself about gardening trends and ideas. And finally, it is a time to complete the few but important tasks needed in February to prepare for the coming growing season.

Winter Interest

Autumn joy sedum keeps its color and form. Photo: Margerie Hicks

If you refrained in the fall from cutting down ornamental grasses, perennials with balls of seeds like echinacea, or plants that keep their color and form, you now have interesting winter patterns and shapes to enjoy. You have also helped provide shelter and food for wildlife, such as birds and insects.

If you don’t already have any sedum Angelina, make a note to plant some in the spring to enjoy next winter. It is a ground cover that is light green in the spring, yellow in the summer, and orange with green accents in the winter. It provides a wonderful splash of color in the winterscape.

Sedum Angelina adds multi-season beauty. Photos: David J. Stang, CC BY-SA 4.0 via Wikimedia Commons

Gardening Edification

• Expo: The annual Colorado Home and Garden Show runs from February 24^thto March 3^rd. Master Gardeners will be on hand to answer gardening questions at the large CSU Extension display. Be sure to stop by and say hi.
• Books: You may have some gardening-related books waiting to read on a cold winter night, but in case you want suggestions check out our earlier post,  Winter Reading for Gardeners.
• Websites: CSU Extension’s website offers research-based fact sheets and videos on a wide range of gardening topics. Additionally, the internet is filled with gardening information and pictures. The most reliable sources have an “.edu” extension on the address, indicating an affiliation with university horticulture/agriculture research.
• Gardening classes:  Local garden shops and the Denver Botanic Gardens offer classes on many topics that may pique your interest. You can also find a wide array of webinars offered by CSU Extension here.
• Take our reader survey:  We’d love your feedback and ideas for future posts. Find the survey here. Survey closes February 18^th.

February Tasks

Deep watering tool. Photo: Margerie Hicks

There are a few tasks that should be done and many that could be done this month. A good overview can be found in this Late Winter Garden and Lawn Care fact sheet. Key tips include:

• Water:  All trees, shrubs, and perennials will benefit from regular winter watering, especially those that are less than two years old. Water once a month on days when the temperature is 40 degrees or warmer with no snow cover. Click here for a fall and winter watering fact sheet that will make your efforts most effective.
• Mulch:  Woody plants benefit from mulch to preserve soil moisture. Rock or gravel mulch is useful in retaining heat. Apply as needed.
• Prune:  This is a good time to prune broken and unwanted branches from trees and shrubs, especially fruit trees.

Enjoy your gardening leisure in February. May will be here soon enough.

Speaking of May don’t forget to mark your calendars for our amazing plant sale!

Colorado Gardening Calendar for January 2024

Early January at the Denver Botanic Gardens Photo: Linda McDonnell

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

It may be tempting to kick back and think there is nothing much to do in the garden this month. And while it is not the busiest time, taking a few steps when needed will set plants, trees, and lawns up for future success.

Winter Watering – January’s Most Important Task

It’s important to water trees, shrubs, perennials, and lawns during extended dry periods of 2-4 weeks. Supplemental water provides root systems with moisture that is critical to long-term plant health. It is especially crucial for new plants (1 year old or less) with smaller, less developed roots. Without this added moisture, plants may exhibit stunted growth, be more susceptible to disease, or die. Often decline is not noticeable till next summer when the root system can’t support the plant’s vigorous growth.

Water early in the day when temperatures are above forty degrees. Give plants a good soak – 8 to 12″ deep and out to the drip line of trees. Find more information on winter watering here.

Branches of  ‘Carol Mackie’ Daphne will easily split under heavy snow. Photo: Linda McDonnell

Trees and Shrubs

Heavy snow can crush or bend the limbs of trees and shrubs. Remove it by lifting branches lightly from the bottom with a broom to avoid breaking limbs. The branches will spring back as if to say thanks.

Prune any storm-damaged limbs as needed to prevent further breakage. Find additional post-storm tips here.

Perennials

Watch for signs of heaving such as cracked soil and raised crowns. This can happen around newly planted perennials when temperatures fluctuate widely. Heaving can expose and damage roots and kill plants. If heaving is present, check moisture, add soil or compost around the plant, and top with mulch.

Speaking of mulch – spread more where needed; it will help moderate temperature extremes.

Remove any diseased foliage that’s lingering in your beds to reduce the chance of infesting next season’s growth. Discard the foliage in the city’s green compost bin or trash. Home compost systems don’t get “hot” enough to destroy pathogens.

Plan Ahead

Should you keep or toss old seed packets? Learn how to tell here.

Scour online and print catalogs to find tried-and-true plant varieties along with new, buzz-worthy introductions.

The CSU Soil Testing Lab opens on January 21^st. If the ground is workable, consider beating the spring rush and sending a sample for analysis this winter. Find directions for digging the sample, using the results and costs here.

Check out the line-up of CSU’s no-cost webinars. There are lots of topics to choose from including turf alternatives, CSU test garden results, and water-saving tips. Find the full spring schedule and recordings of past webinars here.

Explore CSU’s resources for research-based gardening information that will make this year’s garden the best one yet.

Winter Conifer Care for Year-Round Interest

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

Conifers! They occur naturally everywhere in Colorado (albeit less so at plains elevations under 6700 feet). And they’re everyone’s go-to tree or shrub for filling a hole in the landscape or adding hassle-free continuous color. They’re so numerous and large that we often forget that their successful cultivation requires more than finding suitably large and sunny spots for placement and marveling at their spectacular (and automatic) growth. There are, however, some steps to maintaining these gorgeous plants in the dryness and cold of Colorado.

First all, let’s define the term “conifer”: it’s basically a tree or shrub with needles that produces seeds in the form of cones. Find a thorough discussion of the division Pinophyta/Coniferophyta here.

Planting

A winter care routine begins with planting properly: take a look at CMG Garden Notes Tree Selection: Right Plant, Right Place before shopping for a tree or shrub. (This publication includes a link to the Front Range Tree Recommendation list.) Conifers generally prefer sunny sites and good drainage, but moisture needs vary by species. Determine how much watering you’ll need to do to maintain the health of your plant – including winter watering so be sure to consider access to a water source when selecting a location.

Next, make sure that the planting site is large enough to accommodate a mature plant; that cute Colorado blue spruce in its three-gallon nursery pot will eventually reach a height of 30 to 60 feet and require enough room for a 20-foot spread. Consider if a mature tree will interfere with power or water lines, or property access. Remember that winter dryness can take a toll on evergreens, so place it in a sheltered spot or take steps to prevent desiccation (more on that later). Mulching to keep roots cool and moist, especially during initial growth, is a must.

Selection

If you like the look of a particular species but can’t find enough room in your garden for it, look for dwarf varieties. If your planting options are limited to containers, check out Monrovia’s The Best Conifers for Containers (and How to Care for Them). If you’re planting in the ground but would like to stay strictly native, read the CSU Fact Sheet Native Trees for Colorado Landscapes (remember that natives have the advantage of NOT having to adapt to our growing conditions while they’re establishing themselves in the landscape).

Monrovia offers some good suggestions for selection, planting, and care in Your Complete Guide to Growing and Caring for Conifers (this is a commercial site, so be prepared to see lots of their stock!).

Initial Care

Once the plant is in place and (we hope!) flourishing, maintain care throughout the season as outlined in CMG Garden Notes Care of Recently Planted Trees. Consult the CSU Fact Sheets for Trees and Shrubs for specific advice on planting, pruning, watering, and diseases of conifers and other woody plants. Proper irrigation is especially important, so water when the soil around the tree is dry to a depth of one inch. Continue irrigation throughout the fall.

Winter Care

Needle desiccation in the winter months can occur at the Denver elevation when precipitation levels are low, and plants aren’t receiving supplemental watering. Water all perennial plants, trees, and shrubs to a depth of one inch when the air temperature is above 45F and the soil is unfrozen.

Be aware that not all needle desiccation and drop result from insufficient watering; many species shed needles naturally at periods ranging from one year to every 17 years. Deciduous conifers such as larch and bald cypress drop all of their needles in the autumn. If needles in the center of a tree such as a pine turn brown, that’s normal shedding, but browning at branch tips is a concern. Take a look at the CSU Fact Sheet Environmental Disorders of Woody Plants for more information on this subject.

Many Front Range gardeners love arborvitae and despair at their seemingly inevitable winter damage. Wrapping the plants in burlap and/or using a protectant like Wilt-Pruf® or CloudCover® can help, but as noted above, the best protection for vulnerable plants is proper siting. Plant arborvitae and other tender conifers on the lee (downwind) side of the garden, or next to a house or shed. Remember that plants can cope with a variety of situations, even temps of -15F and extended dry periods (with some help). Good luck with your winterizing!

Colorado Gardening Calendar for October 2023

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

October is my favorite month to enjoy the vibrant, intense colors and crisp autumn breezes of Colorado. Gardeners need to adjust their routines to ensure a healthy, beautiful garden next year by completing the maintenance tasks outlined here that apply to your garden.

Vegetable Garden

Harvesting carrots and beets photo by a-lesa on iStock

• Harvest and Preserve: Your vegetable garden may still be yielding some late-season treasures. Harvest your remaining root vegetables and squash. Store them in a cool dry place for use throughout the winter. Consider canning or freezing surplus produce or donating some to a food bank. For canning information click here. The first frost will probably occur mid-month, so don’t be caught harvesting one night in a freezing drizzle (I’m speaking from experience); observe the weather reports each day.
• Clean and Compost: Remove spent plants and weeds from your garden beds to prevent diseases and pests from overwintering. Compost healthy plant material to create nutrient-rich soil for next spring. Learn more about composting techniques here.
• Plant Cover Crops: Protect your garden’s soil during the harsh winter months by sowing cover crops like winter rye. These cover crops help prevent soil erosion, suppress weeds, and improve soil structure. When spring arrives, you can simply turn them under to add organic matter to your soil.

Trees and Shrubs

• Blow out the sprinkler system: When water freezes the pipes may crack.
• Wrap the trunks of trees that have been planted in the last one or two years:  Click here for details.
• Prune and trim: See this Colorado State Forest Service pruning guide. Do not prune spring flowering shrubs or you will be removing next year’s blooms. In the future, prune these soon after the blooms fade. 
• Irrigate: Continue to water, and plan for monthly watering all winter on days the temperature is above 40 degrees Fahrenheit.

Lawn Care

child playing in leaves photo by Scott Webb on Unsplash.com

• Rake leaves:  First form big piles so the children in your life can play in them. Then compost the leaves at home or take them, ideally in paper bags, to one of the leaf drop sites provided by the City of Denver. Click here for locations, dates, and times.
• Fertilize: Click here for details on proper lawn fertilization.
• Aerate: Unless your lawn has been aerated since spring, see the sub section of this fact sheet called “Core Cultivation or Aerating” to learn more.

Perennial Flower Beds

Planting tulip bulbs photo by LianeM on iStock

• Plant spring bulbs: Tulip, hyacinth, crocus, daffodil and other spring blooming bulbs can be planted when the weather gets cool. See this fact sheet for important considerations in selecting and planting bulbs.
• Divide and transplant: October is the ideal time to divide overgrown perennials. This process rejuvenates the plants and can also provide you with new additions to your garden. Transplant them to new areas or share them with fellow gardeners.
• Cut back and clean: Trim back faded perennial foliage and remove debris from your flower beds. Consider leaving some plants uncut, such as ornamental grasses and dried echinacea blossoms, as winter habitat and seeds for birds. These and other plants, such as Autumn Joy sedum, provide winter interest to the garden.

Annual Flower Beds

Ornamental Cabbage photo by Santi WiWatchaikul on iStock

• Plant cool season annuals: Extend the beauty of your garden by introducing cool season annuals like pansies, violas, and ornamental kale or cabbage. These hardy plants can withstand the cooler temperatures of late fall and early winter, adding vibrant color to your landscape.
• Enjoy blooms inside: Before the frost, cut any remaining blooms, such as roses, bring them in the house, and put in vases to enjoy the last summer color.

Other Tasks

• Bring in house plants from the patio before the inevitable frost. First, hose off the summer dust and any insects, then let them dry while still outside.
• Wash and store pots; clean, sharpen, and oil garden tools; store for the winter.

October is a transitional month in Colorado gardening. Use this month to prepare your garden for the winter months ahead. Remember to adapt these guidelines to your specific microclimate and garden conditions, and always consult research-based resources such as https://extension.colostate.edu/topic-areas/yard-garden/ for the most accurate advice. Happy gardening.

Denver Residents: Share Your Thoughts on the Future of the Urban Forest

Denvergov.org

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

Have you heard that Denver Parks and Recreation and the Office of the City Forester are collaborating on the city’s first Urban Forest Strategic Plan? It’s important work as improving the urban forest – which includes trees in public and private spaces – will lead to a greener, healthier, and cooler Denver. The purpose includes refining and updating our tree canopy goals and providing a “common and equitable vision” for the future of the city.

Denver residents can get involved by completing the survey linked below. Do it soon, as the extended deadline for submissions is this Friday, September 9^th at midnight.

Learn more about the Urban Forest Strategic Plan and sign up for email updates here.

Survey Link (English): Urban Forest Strategic Plan – Public Survey #2 (surveymonkey.com)

Survey Link (Spanish): Encuesta del Plan Estratégico de Silvicultura Urbana (UFSP) – Encuesta n.º 2 Survey (surveymonkey.com)

Thanks, in advance, for your support!

Colorado Gardening Calendar for August 2023

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

August is a fabulous month for enjoying your garden. Much of the work from earlier in the season will have paid off at this point. Since August is often hot and dry, it’s important to make sure your garden is getting the right amount of water, and to remain observant for stressed plants. Mark your calendar to get these gardening to-do’s done in your yard and garden.

Also this month and through September 15^th, CSU Extension is accepting applications for the next Colorado Master Gardener class. To learn more about our program, explore the resources at www.ColoradoMasterGardener.org and read Let’s Grow Together: Becoming a Colorado Master Gardener by Felicia Brower.

The vegetable garden at the Denver County Extension office. Photo: Merrill Kingsbury

A Yard and Garden Checklist for August

Vegetable Garden

• As your veggies ripen, harvest them, and if you cannot eat them right away, check out these good ideas to preserve them for later from Master Gardener Lois Margolin.
• How are your tomatoes doing? Growing tomatoes in Colorado can be tricky, with our wide temperature ranges and winds that prevent pollination. Some ideas for helping with your tomato problems can be found in this video on the PlantTalk website.
• Extend your gardening time by planting cool season vegetables such as peas, broccoli, and kale.

Trees and Shrubs

• Pay attention to signs of stress and desiccation in woody plants, and supplement with water as needed.
• Prune back summer blooming shrubs that have finished flowering, and that will bloom next year on this season’s growth. (It’s too late to prune spring blooming shrubs such as forsythia and lilac.)
• Always avoid trimming trees when they are water stressed by hot and dry conditions – they need to conserve all the energy they can this time of year.

Lawn Care

• During periods of high temperatures, a lawn may need as much as 2.5 inches of water or more per week.
• Mid to late August is a good time to over-seed bare spots in the lawn.
• The best defense against weeds in the lawn is thick and healthy grass, and you can encourage this by cutting the grass high – about 2.5 inches or higher.

Photo: Gail Leidigh

Perennial Flower Beds

• Some plants will start going to seed this time of year. If you don’t want the plant to self-seed, seed heads can be cut back. Or leave the seeds for the birds to enjoy.
• Weed ‘em and reap: Continue weeding the yard and gardens now, and reap the rewards later.
• Take note of what worked this year and what did not. Many perennials will be on sale at the end of summer and this fall, and it is a great time to fill in bare spots or replace plants that didn’t make it.

Annual Flower Beds

• Check the soil moisture in pots and hanging baskets frequently, as they will dry out quickly in the summer heat and wind.
• Clear and thin out plants that are fading, and make room for fall annuals that love the heat such as angelonia, ornamental kale, and daisy rudbeckia.
• Dead-head to encourage growth of new blooms.

Enjoy your garden this month!

Festival of the Unfamiliar: New and Under-used Plants for the Colorado Garden

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

One of the more rewarding aspects of gardening in Colorado is that a wide variety of plants can be grown here, even with our dry climate, high elevation, and unpredictable weather. The former advantage of selection, however, is often overlooked as we concentrate on coping with the latter disadvantages of our environment. We can remedy that by looking at resources (some with newly available and pending varieties) that will broaden our plant choices and result in more varied gardens that will succeed in our challenging climate.

Sulfur Flower

Desert 4 O’Clock

Buffaloberry

SPREAD A WIDE NET, FIND WHAT’S UNUSUAL TO YOU

Categorizing plants as “unusual” or “less used” is highly subjective and likely not useful to most gardeners. A rarely found plant also may be unsuited to our growing conditions. To avoid subjectivity and unsuitability, let’s look at resources that are sufficiently large and broad for gardeners to not only see the most desirable plant choices for our area but also decide what’s “common” and “uncommon” based on their own experience. 

To find many recommended trees, shrubs, and perennials that might fall into the “underused” category, consult one or more of these publications from CSU Extension:

• Low-Water Native Plants for Colorado Gardens: Front Range and Foothills – this includes many great plants for our area. Take special note of the little-used Gambel oak (Quercus gambelii), serviceberry (Amelanchier alnifolia), and desert four o’clock (Mirabilis multiflora) that make gardens both lovely and distinctive.

• Front Range Tree Recommendation List – see ratings of numerous selections for local gardens, including hints on suitability and cultivation. Many unusual, knockout plants are here.

• Xeriscaping: Trees and Shrubs – this fact sheet suggests desirable but uncommon woody plants like buffaloberry (Shepherdia argentea), Cheyenne privet (Ligustrum vulgare ‘Cheyenne’) and fernbush (Chamaebatiaria millefolium) that will thrive in a waterwise environment.

• Native Herbaceous Perennials for Colorado Landscapes – here we see favorites like Colorado columbine (Aquilegia caerulea) and blanket flower (Gaillardia aristata), along with the often-overlooked Maximilian sunflower (Helianthus maximiliana) and sulphur flower (Eriogonum umbellatum). 

Local and mail-order nurseries and horticultural websites love to present unusual and new offerings:

• High Country Gardens links to a page of unique plants on its website. Click on “Unique Plants” in the “Perennials” menu to see what’s available now – and be sure to scroll down to see plants that are out of season or sold out that may be available later. The HGC site also features 145 Plants for Colorado that will be unfamiliar to many visitors.

• The Colorado Native Plant Society website includes divisions of natives by life zone on its Colorado Plants and Habitats page. (Finding natives for sale can be tricky, but we can report that after a long search, the mountain ninebark (Physocarpus monogynus) finally turned up at a Denver nursery. A Google search for a plant by botanical name may also help to locate it on a nursery website.)

• The City of Boulder website offers a page designated as Native Plant Gardens Gallery and Growing Tips. As these recommendations are made for gardens in that area, check out the plant lists at Harlequin’s Gardens in Boulder to see if any are for sale locally. 

• Local nurseries stock many new and unusual native and adapted perennials, trees, and shrubs; visit your favorites in spring and fall to see what’s offered. Check their websites in spring for projected offerings.

• Mail-order catalogs are a treasure trove of new or rarely offered genera, species, and varieties that flourish here; avoid the big feeders and drinkers marketed for wetter and more temperate areas of the U.S. (Buy a plant from one company, and catalogs from the others will find their way to your mailbox.)

• Visit the popular website Dave’s Garden to find mail-order nurseries selling a desired plant in “Plant Scout” on the “Products and Sources” page. 

FOR THE NEW AND/OR SEXY, KEEP AN EYE OUT IN SPRING (AND FALL)

Bookmark these websites to get the first crack at what’s coming up in the spring:

• Search for suitable plants at Proven Winners;  their selections are popular at our local nurseries, and many will ship online.

• Use Monrovia to search by ZIP code and numerous other filters for plants that often wind up at local retailers, or order online for delivery to a local nursery.

• See new, well-vetted introductions and lots of advice from Plant Select every spring.

Have a question about this post (or anything else)? As always, please contact the Denver County Extension with your gardening questions.

Colorado Gardening Calendar for July 2023

By: Valerie Podmore, CSU Extension-Denver Master Gardener since 2020

Roses in bloom for a “hot” minute, photo by Valerie Podmore

With all the precipitation we’ve had this year, our gardens have been busting out all over with beautiful blooms, vegetables are loving it and of course weeds are growing like gangbusters. I bet many of us have not really had to water much yet…how great is that?!

This month let’s get out there and keep on top of the bounty that this amazing weather has brought us, knowing that in Colorado the weather can turn on a dime, so we need to be prepared for anything.

Vegetable Garden

• This is the month when we can start harvesting our ripening vegetables, fruits, and herbs.
• Look to plant vegetables for fall harvest. This information sheet has great ideas!
• Since July is typically hot and dry, we may need to water but make sure not to water from above to prevent mildew and other maladies from forming.
• This article is a great overall guide on caring for veggie gardens. I’ve bookmarked it for my future reference as a beginner veg gardener!

Trees and Shrubs

• While we’ve had ample water this year, we still need to watch the weather and make sure our trees and shrubs are adequately watered when we’ve received no precipitation in 10-14 days to prevent disease. Denver Water has a nice, succinct guide to help.
• Emerald Ash Borer has been detected in a small area of Littleton and Carbondale (both new locations) and this information can help you plan ahead if you have ash trees.
• Our landscape shrubs are probably growing beautifully right now and seeing some dead branches might drive us crazy (us = me), so know that while this is probably not the prime month for pruning, removing these dead canes can help. This pruning guide contains so much great information I’ve had to read it over more than once.

Lawn Care

• Our lawns are probably quite happy with all the moisture we’ve received, and let’s keep them thriving with proper care.
• Fertilizing can help if done correctly at the right time.
• If you are considering converting your lawn to less water-intensive landscaping, this info sheet contains a multitude of conversion methods and ideas.

Bunny in my garden, relaxing and digesting the flower leaves it just ate, grrrr! photo by Valerie Podmore

Perennial/Annual Flower Beds

• Both perennials and annuals can benefit from deadheading to promote more flowering and preventing them going to seed (if that’s what you want).
• Pull those weeds to prevent them taking over your flower garden!
• This document has a plethora of information about annuals and perennials during low-water periods because let’s be honest, we WILL get back to a lower water situation soon enough.

Oh, just one more thing (a la Columbo!), don’t forget that the “wonderful” Japanese Beetle will begin to make its appearance this month to destroy our hard work, so take a look at this article to learn more on this pest and how to battle it.

As always visit the CSU Extension Yard and Garden website (https://extension.colostate.edu/topic-areas/yard-garden) for more gardening tips.