CO-Horts Blog

Monday, June 21, 2021

Highlights of 2021 Plant Select® Meeting

 by Yvette Henson

I was so excited to attend the annual Plant Select® Meeting this week.  After 15 months of COVID restrictions, it was held in person at Denver Botanic Gardens! I thought I would share a few of the highlights of the meeting for me.

 If it weren’t enough of a treat to be able to attend in person, the gardens were bursting with blooms and green foliage, fed by this spring’s rains.  

It isn’t possible to pick a favorite part of the garden.

This is a view of the new Cactus Garden.

 If you do not know already, Plant Select® is a non-profit plant introduction program that is a collaboration between Colorado State University, Denver Botanic Gardens, and professional horticulturists.  The goal of Plant Select® is “to create smart plant choices for a new American Landscape inspired by the Rocky Mountain Region”.  There are many Plant Select® Demonstration Gardens throughout Colorado.  For more information visit 

Ross Shrigley, is the Executive Director of the Plant Select Program.
The first speaker was Kelly D. Norris, a landscape designer from Iowa.  He is author of New Naturalism: Designing and Planting a Resilient, Ecologically Vibrant Home Garden.  My take-a-way from his talk was “abundance fosters resiliency”.  He recommended ‘overplanting’ 135%-- planting in multiples of many different species. 

Kelly D. Norris

Kelly was followed by Panayoti Kelaidis, Senior Curator and Director of Outreach for Denver Botanic Gardens.  Panayoti shared about the origins of the Plant Select® Program and the people and the plants that started it all.  What was driven home to me was that the people are the most important, despite the love of plants. 

Panayoti Kelaidis

Katie Collins, City of Fort Collins and Deryn Davidson, CSU Extension Boulder County, shared the Top Ten Tips for Water Management, especially regarding Plant Select® plants.  I was pleasantly surprised that they (as well as other presenters) encouraged us to taper off irrigation to our plants over time and that if the plants do not make it, that means they aren’t meant for our arid climate in Colorado.  This practical talk was most helpful to me since we are currently installing a new irrigation system to our Plant Select® demonstration garden at the San Miguel Basin Fairgrounds in Norwood. 

Katie Collins and Deryn Davidson

Lunch was followed by tours of different gardens led by garden horticulturists. We started with Dan Johnson at the Water-Smart Garden, followed by Mike Bone in the Steppe Garden, Sonya Anderson, at the Plant Select® Garden – Sonya also won and award this year for her contribution to the Plant Select® program.  Then we went to the Rock Alpine Garden where Panayoti told us more about the evolution of that garden.  We ended at the O’Fallon Perennial Walk with Bridget Blomquist.  She told us her design plans to redo this garden. 

The day ended with Dr Klett, David Staats and Ross Shrigley loading a few choice Plant Select® plants into our vehicles to plant in our local Plant Select® trial gardens.  And then… I made my way back through the gardens for one last look.

Plant Select Border, Denver Botanic Gardens

Water Smart Border, Denver Botanic Gardens






Monday, June 14, 2021

Garden for Pollinators, the choice is clear! Or is it?

 Posted by John Murgel, Douglas County Extension

If you have not yet noticed, June is Colorado Pollinator Month!  National Pollinator week kicks off next Monday.  During this month and beyond, you may find yourself the recipient of a lot of different advice on how to best support pollinators in your garden.  I think all of it is given with the best of intentions; differences, sometimes strong differences, exist.  Truth be told, pollinator (and broader ecosystem) support by human activities is an area of active research and practical conclusions are difficult to draw.  To quote Dave Armstrong, professor emeritus at CU-Boulder, “Ecology is not rocket science, it’s harder.” 


Mason bee close-up
Native Bees are cuter than you think!

Here’s a conundrum perhaps not unfamiliar to many Colorado gardeners:  should I plant only natives, from local seed sources? I hear this recommendation (sometimes presented as an imperative!) frequently.  Most of my garden is a mix of non-native and “native” plants.  I put native in quotations because I have collected exactly ZERO of my plants from wild seed.  I stand by this decision—having thousands of gardeners added to the list of seed predators seems like a great way to drive wild populations of native plants to extinction.  So out the window goes “local population source” for my natives.  That will lead a conscientious gardener to the risk of genetic material from my "cultivated natives" getting into the wild populations nearby, at the risk of reducing the wild population’s fitness with “weak” domesticated genes.  At least there’s little risk of a non-native plant doing that!

 Perhaps I shouldn’t worry too much about gene flow.  After all, the “natives” I’m growing aren’t all native to my zip code, or even to my county.  Many are “Colorado natives,” or natives from the Western US, chosen more for drought tolerance than for their geopolitical pedigree.  Many true natives from undisturbed places around my home would shrivel on a day like today with the reflected heat and other challenges associated with highly modified, man-made landscapes. At least my questionable natives and non-natives have flowers to visit!

A mixed native and non-native planting
A mixed native and non-native planting

 Maybe I should plant a tree to help shade that hot landscape.  A little cooling provided by all that transpiration wouldn’t hurt either to mitigate the urban heat island effect!  Trees don’t naturally grow in my neck of the woods, so “native” goes out the window immediately.  I’ll have to water a tree, too.  But if the house is cooler naturally, the carbon-cost of cooling it with electricity on a day like today will be less.  Mitigating climate change would help pollinators, right?  What’s the “greenest” choice?  Decision paralysis seems inevitable—how to make the right choice!?

A native bumble bee visits a non-native plant
Native bee and non-native plant

 Some decisions you might make in the garden are obviously bad for pollinators—putting up butterfly houses, growing sterile, non-pollen producing plants, or liberally using insecticides come to mind.  Many other decisions, though, are good, or at least less clear.  Take the decision to plant flowers.  Should I only grow native plants for the native bees?  Plants with which they’ve co-existed for millennia?  In my garden, all the bees like all the plants—I see non-native honeybees on native plants, and native, wild bees foraging on my non-native drought adapted plants like Eremurus and Salvia.  Bumblebees really seem to like Salvia, with Echium close behind.  Should I remove the non-natives?  I have mixed feelings about honeybees, so where would that leave me?  Which suite of plants is “best”—for pollinators, for water, for climate change?  We may never know.  But don’t let the perfect get in the way of the good.  Grow some flowers, pick plants that grow where you live, and watch the invertebrates!   

Monday, June 7, 2021

June is Colorado Pollinator Month

Posted by: Jan Behler, Douglas County Colorado Master Gardener

When people hear the word “pollinators” they usually think of bees, but ants, beetles, butterflies, flies, hummingbirds, and moths are also primary pollinators in our state. Pollination is the transfer of pollen to stigma, within or between flowers and plants. A plant’s flowers need to be pollinated to complete their life cycle of producing fruit and seeds that make more plants.

Photo Credit: John Murgel
Photo Credit: John Murgel, Douglas County Horticulture Agent

Pollinators are nearly as important as sun, soil, and water in the production of most fruits and vegetables. According to the U.S. Department of Agriculture, over three-quarters of the staple crops that feed the world rely on animal pollination. On a small scale, a lack of pollination results in a fruitless tree. However, since many of the foods we eat require pollination on a larger scale that could mean a shortage to our food supply. So, the month of June has been officially designated as pollinator month to help bring awareness to the importance of pollinators.

Photo Credit: John Murgel, Douglas County Horticulture Agent

Here are a few action items to protect these important contributors to food production and beauty in our world:

  • Plant flowers in groups. Groupings or clumps of plants will attract more pollinators than single plants scattered. A bee or butterfly will feed more if they don’t have to travel too far between plants.
  • Think of providing flowers throughout the season. Plant a variety of plants that flower at different times to offer continuous pollen and nectar sources. A few examples of spring plants could include blue flax, allium, crocus, and serviceberries. For summer you might try blanket flower, bee balm, lavender, and sage.  For fall, hyssop, coreopsis, common sunflower, and golden rod.
  • Use insecticides carefully, if at all. This is self-explanatory!
  • Grow native flowering plants which are adapted to local soil and climate. Plant Select has many great plant recommendations that are suited to Colorado and known for their hardiness and low water consumption. For a good list of native plants, check out the CSU Extension Website for the fact sheets: NativeHerbaceous Perennials for Colorado Landscapes – 7.242 and CreatingPollinator Habitat – 5.616
Photo Credit: John Murgel, Douglas County Horticulture Agent

It is quite amazing but there are over 950 species of bees in Colorado alone. Did you know that hummingbirds can fly backwards and upside down? Also, t
he average lifespan of those beautiful adult butterflies is roughly three to four weeks so take a moment to look around in your yard and notice the pollinators and be kind to them this June and always!

Friday, June 4, 2021

UnBEElievable: The Benefits of Pollinators in Our World

Posted by: Lisa Mason, Arapahoe County Extension

Let’s celebrate pollinators! June is Colorado Pollinator month and June 21-27th is National Pollinator Week!

Pollinators provide so many benefits to humans and ecosystems that they deserve more recognition than just one month out of the year! Education and awareness is critical because pollinators are declining all over the world for a variety of reasons including habitat loss, pesticides, parasites, diseases, climate change, etc.

Pollinators around the world include bees, bats, flies, beetles, wasps, ants, butterflies, moths, and some species of reptiles and small mammals. Bees are among the most efficient pollinators because the pollen sticks to the hairs on a bee.

Why should we care about pollinators?

Pollinators provide valuable ecosystems services. They transfer pollen grains from one flower to another which enables the plants to reproduce. Here is a closer look at the value pollinators have to humans and ecosystems:

  • 75% of more than 240,000 plant species rely on pollinators for reproduction.
  • The global production of crops that depend on pollinators is an industry worth up to US $577 billion annually.
  • Bees help to pollinate 1/3rd of the human diet including the most nutritious part of our diet—fruits, vegetables and nuts.
  • In addition to crops, they pollinate the food for livestock that contributes to the meat and dairy industry.

In addition to providing nutritious food, pollinators offer a variety of other ecosystem services that are less known. Think of all the benefits that plants provide us. We can thank pollinators for facilitating plant reproduction for many of those plants. Examples of ecosystem services include:

  • Raw material production
  • Recreation
  • Climate regulation
  • Erosion control
  • Nutrient cycling
  • Clean air
  • Cultural value
  • Medicinal plants
  • Plant-based dyes
  • And more!

The Buzz with Bees

All bees should be celebrated! Our planet has an incredible amount of bee diversity! We have approximately 20,000 species of bees worldwide. We have over 900 species in Colorado! Most of us are familiar with the honey bee (Apis mellifera), a non-native bee species to the United States. The honey bee was brought over from Europe in the 1600’s and is a domesticated species. While they are not at risk of going extinct, they do face a variety of challenges like varroa mites. Honey bees are an important species economically and for pollinating food crops. They also provide us with honey, wax, and other products. Native bees provide an incredible amount of biodiversity and many native bees have specialist relationships with the plants they pollinate meaning other bees are unable to pollinate those specific plants. A couple of examples include squash bees that are very efficient at pollinating pumpkins and squash, and bumble bees that “buzz pollinate” plants. Buzz pollination occurs when a bee has a strong vibration frequency that allows the plant to release the pollen. Plants that need buzz pollination include tomatoes and peppers.

While writing this blog post, I took a break to water flowers in my yard. I came across this little bee who landed on my hand. This bee was less than a quarter of an inch, but she was working hard a pollinating the catmint (Nepeta spp.). She is closely related to Mason bees (Osmiini Tribe). We need a microscope to determine the exact genus, but she is likely a Hoplitis spp. or Heriades spp. bee. She has special pollen-collecting hairs on the underside of her abdomen. She is also a cavity-nesting bee.

How are you going to celebrate Colorado Pollinator Month?

Here are some ideas:

  • Observe pollinators in your backyard, parks, or open spaces. Look for visiting insects and birds that might be pollinating blooming flowers. Notice the diversity of flower visitors, and how hard they work at collecting pollen and nectar. If you take photos, you can upload them to iNaturalist, a biodiversity science database of observations. You can also explore iNaturalist to see what others are observing. 
  • Plant flowers and provide pollinator habitat in your landscape. No landscape is too small or too big. Planting some pollinator-friendly flowers or providing some habitat space will benefit the pollinators that visit. How can you provide habitat space? Keep in mind that approximately 90% of bees are solitary which means they mostly do not interact with other bees with the exception of mating.  Of the solitary bees, about 70% live underground and the other 30% are cavity nesters.  Here are some resources:
  • Join the Native Bee Watch Community Science program! All training free and provided. You can watch bees in your landscape and collect data on your observations. Register here by June 13th. Learn more about the program at Check out the CSU Source Story on Native Bee Watch.
  • Attend a virtual class during National Pollinator Week! Register here to take a one-hour class on June 25th at 12pm on who the pollinators are and how to support them. 
  • Spread the word! Check out the resources for National Pollinator Week and share with your friends, families, and neighbors. Share your photos on social media and use the hashtags: #ColoradoPollinators #PollinateCO #NativeBeeWatch #CSUExtension 

Tuesday, June 1, 2021

Be Gone, Grass (in landscape beds)!

 Posted by: Alison O'Connor, Larimer County Extension

Do you battle grass creeping into your landscape beds? Me too. And it isn't fun dealing with it. I've tried all the recommendations--pulling, mowing, digging, and herbicides. Now, before you label me as a "spray head", I'm not. I pull a lot of weeds in my landscape, mostly because I find it therapeutic. I love listening to music, filling up a bucket of weeds, and appreciating my landscape on a micro-level. However, I also have my limits, and trying to dig out bluegrass around my delicate plants isn't fun.

Kentucky bluegrass creeping in my Heuchera (coral bells).

Fortunately, the herbicides available for this problem are extremely effective and readily available. If you choose not to use herbicides, then keep on keepin' on with pulling, digging, and using mulch. These efforts can be successful, but persistence is key. Do it regularly.

If you want to consider herbicides, then look for products that contain either fluazifop or sethoxydim. There's a third, clethodim, but it tends to be more expensive. These herbicides are sold in products like Ortho Grass B Gon, Fertilome Over the Top II, Bonide Grass Beater, Monterey Grass Getter, etc.  

One of many options you can use to selectively remove grass from landscape beds.
This is not an endorsement of any particular product.

[Side note: I absolutely LOVE saying "fluazifop" and find it to be the most fun chemical name to use in everyday conversation. Flew-as-uh-fop. Fabulous.]

These are selective herbicides, meaning they will remove grass selectively from other plants. Namely, they will kill grasses, but leave your broadleaf plants unharmed. But they can injure/kill other grasses (ornamental grasses), iris, and other monocots. So read the label and use carefully.

But they do work! And usually in one application.

Use of fluazifop in my front landscape bed on bluegrass;
nearby plants included sedum and spring bulbs.

Don't worry, sedum, help is on the way!

Hang tight, little sedum, you'll be free from that bluegrass soon.