CO-Horts Blog

Thursday, October 22, 2020

5th Annual Pollinator Summit Goes Virtual

 Posted by: Deryn Davidson, Boulder County

Photo by: Arianna Kelley Rawlsky

There is no doubt that more and more people are becoming aware of the important role pollinators (insects, birds and mammals) play in everything from the food we eat, to the clothes we wear. Pollinator gardens are being planted in neighborhoods and researchers spend their careers learning about every facet of these fascinating creatures. Whether you are already immersed in this world or just curious about the state of Colorado’s pollinators, you might be interested in joining the Colorado Pollinator Network (CPN) for their 5th annual Pollinator Summit on Thursday, November 5th. Typically an in-person event, the 2020 Summit will be held virtually for everyone’s convenience and safety.  

The theme of this year’s summit is to look at how we can bridge disciplines and promote conservation actions to protect pollinator habitats and foster pollinator diversity. The organizers hope to welcome a broad audience to explore the state of pollinator conservation in Colorado, identify obstacles to conservation action across disciplines, and identify strategies to overcome the challenges of pollinator conservation here in Colorado and beyond.

The Summit has an array of speakers lined up including international bee expert and bestselling author, Dave Goulson, Professor of Biology at University of Sussex in England. He has published more than 300 scientific articles on the ecology and conservation of bumblebees and other insects. In his talk he will discuss “why insects are in decline, and suggest how we should tackle this crisis, first by turning our gardens and urban greenspaces into oases for life, and second by fundamentally changing the way we grow food.”

There will be two tracks in which attendees will have the opportunity to listen to expert panels present on various Colorado pollinator topics 1) Education, Engagement and Equity: Inspiring Coloradans to Work for Change; 2) Policy Panel Discussion: Creating and Implementing Policies that Accelerate Pollinator Conservation; 3) Colorado’s Pollinator Research: Building Knowledge to Inform Conservation Action; 4) Managing our Lands to Protect Pollinators and Build Resilient Farms, Rangeland and Cities. Afterwards participants will have a chance to engage in live panel discussions on issues surrounding Colorado pollinators. There will be virtual vendors available throughout the day for attendees to visit as well as poster sessions by area researchers and students.

Sponsors of the Pollinator Summit and the organizing partners include the Butterfly Pavilion, CU Museum of Natural History, Denver Botanic Gardens, Denver Audubon, CSU Extension in Boulder County, People & Pollinators Action Network, City of Boulder, and CU Community Engagement, Design and Research Center.

Haven’t heard of the Colorado Pollinator Network? From their website: “The Colorado Pollinator Network was established in 2016 with a mission to bring organizations together to work collaboratively to conserve, protect and create pollinator habitat while educating communities across the state of Colorado to protect our pollinators. The Network allows for organizations and individuals throughout Colorado to collaborate to make a positive impact on the health of our state pollinators. This group shares information about the best practices, resources and knowledge to support education initiatives, conservation, restoration and creation of habitat and research on pollinators in the state.”

For more information on speakers, session schedule and to register visit  

Monday, October 19, 2020

I live in Fruita where the Pine Gulch Fire had the title of the largest Colorado fire until the Cameron Peak Fire exceeded it.  Having to respond to the effects of fire in many ways has taught me a lot this year.  Pardon me if I go off the plant topic a little on and off in this blog, but I hope you will appreciate it.

During our fire I had many mornings where the garden covered in ash.  I learned that the ash was very high pH, coming in around 11!  Seven is neutral and in Western Colorado it is common for our alkaline soils to be a pH of 8.   So 11 is very high.  So hosing or blowing off the ash so the plants would not be harmed by a loss of photosynthesis and the ash is a good idea.  I did end up with one squash plant that suffered.  If your walkways and other hard surfaces are covered with ash, sweep them off and throw it away.  Do NOT add it to the garden.  This is especially dangerous if any structures burned as then you don’t know what might be in the ash.

During Pine Gulch fire I got a question about animals, so here is the information I got from some wonderful CSU experts.  Keep your pets and backyard chickens and other animals inside as much as possible.  Clean their water often as ash can mess up their digestive systems.  Animals don’t need to be breathing the air any more than we do.  Try to watch your local air quality and do your landscaping and gardening when the air quality is not so bad.

The drought, fire and ash got me thinking about defensible space and being ready for an emergency.  My husband is a retired firefighter EMT of 21 years and fought many wildfires.  So we have items in case of emergency in our car, etc...  Make part of your gardening and landscaping thinking and acting to prevent fires around your property.   In this time of drought, wildfires could happen ANYWHERE.  We should all be prepared.

So how can you be prepared in the garden and landscape?  Well, I would start by removing any dead plants.  Deadhead flowers (removing flower stalks that are no longer blooming) as often these dry out.  Plus this will put my energy back in the root system of perennials and shrubs instead of working on producing seeds.  Remove leaf litter that is close to the house or in the gutters.  It just takes one ember to land in a crook of the house where there is debris and a fire starts.  You could start a compost pile away from the house to put plant debris.  Use rock mulch or other materials like flagstone, pavers, or other non-combustible materials closest to the house.  Keep wood piles and other wood products or structures away from the house.  Ideally a zone of lower growing, high-moderate water loving plants would be closer to your house as long as it does not affect your foundation. 

To create defensible space, height should increase as you move away from the house. 

See this website for more detailed information on Defensible Space.,modified%20to%20reduce%20fire%20hazard.&text=Develop%20these%20zones%20around%20each,buildings%2C%20barns%20and%20other%20structures.

Did you know that there are plants that are more fire resistant?  Of course some of that depends on drought and how much moisture is in the plants. .  Choose plants that do not produce a lot of litter under them.  Aspen trees would be a good high altitude garden choice over 5000 plus feet elevation, I personally recommend even higher like 6-7000’ as aspen do not do well in the low Valley’s heat and clay soil.  

Pinyon pine with twig or bark beetle damage, picture from Tri River Area

Now let’s talk drought.  I have been getting many calls about older trees not doing well.  For those of us in town with irrigation, give your trees and landscape a really good drink before the irrigation goes off.  If you live on a large properties or up in the mountains, typically there is not a lot you can do other than depending on Mother Nature for moisture.  But could you water one or a few favorite or most important trees?  If they are mature established trees, water out twice their height or spread and give them a deep soak once a month to a depth of 12-18”.  This will keep them vigorous enough to help ward of insects like bark beetles and borers.  Some trees, like pinion pines, might need some insecticide treatments to prevent ips beetle from investing.  When there are epidemics of insects and there is prolonged drought, the trees are very susceptible to attack.

For trees with lower dead limbs, removing them can decrease fire ladder potential and helps the tree to heal.  Prune evergreens when dormant to prevent attracting insects like bark beetles and borers.  Make sure you use proper pruning techniques and cut outside the bark ridge and bark collar.  For bigger limbs use the three cut method to prevent the limb from breaking and causing trunk damage. Turn these limbs into chips or stack in a wood pile, again away from your structures.  If the plants are diseased or insect infested follow appropriate protocol for that particular issue to dispose of or prevent any spread of issues.

I hate to say it but I am hoping for an earlier winter with lots of moisture to help with the fires and the drought.  We can only do, what we can do the rest is up to Mother Nature.

By Susan Carter, CSU Extension Tri River Area, Horticulture and Natural Resource Agent


Thursday, October 15, 2020

Grow & Give: Community Garden Makes a Big Impact

 By Amy Lentz, CSU - Weld County Horticulture Agent


With the unique situation of the global pandemic that began back in March, many CSU Extension staff shifted gears to create the Grow & GiveTM program. This program took the idea of the victory garden and modernized it for 2020 by creating a comprehensive, statewide horticulture initiative focused on helping people grow a food garden and donate the produce locally to address food insecurity. The program registered almost 600 gardens across 37 counties in Colorado, with participation from individuals, Master Gardeners and community-run gardens. 

During the Grow & GiveTM program’s pilot year, there have been over 1600 reported donations across the state, totaling more than 40,000 pounds of produce! In addition to all of the amazing donations that were spurred by the program, the organizing team created several new resources for participants to help them with their ‘growing and giving’ questions and needs. To learn more about the Grow & GiveTM program, visit  

One particular garden in my home county deserves some serious recognition for their past and present involvement in growing food for donations and their participation in this year's Grow & GiveTM program. The Treasure Island Demonstration Garden donated over 5,580 pounds of produce over the past few months, all donated locally! Although this wasn't their first year growing food for donation (they've been doing that for over 10 years), it was the first year they had to do it while dealing with restrictions due to the pandemic.


Treasure Island Demonstration Garden, conveniently located along the Poudre River Trail in Windsor, is visited by thousands of pedestrians and cyclists each year as they pass by the long garden area. The garden started 13 years ago as a side project for a small group of Weld County Colorado Master Gardeners. In their first year, they grew lots of pumpkins to get the garden up and running. Since then, the garden has grown to be an attractive and educational landmark of the town.

Today, Treasure Island is home to several garden sections including a very large vegetable garden, kitchen garden, dahlia garden, ornamental grass garden, memorial rose garden, a crevice garden and several mixed perennial gardens. 

The vegetable garden has really been thriving this year, with an abundance of crops such as cabbage, broccoli, zucchini, summer squash, onions, and tomatoes and peppers of all kinds! All of the fresh produce is donated to the Windsor Food Pantry for distribution throughout the area to those in need.

We are so proud of Windsor's volunteers at the Treasure Island Demonstration Garden and their continued efforts to help their local community! The Treasure Island Demonstration Garden is located at 1560 7th St. in Windsor, Colorado.

Tuesday, October 13, 2020

Native Shrubs for Fall Color

Yvette Henson, CSU Extension, San Miguel Basin

We all love the golds and oranges of our native aspen and cottonwood trees and we take annual drives into the mountains in late September and October to see them in their glory.  But, we don’t give as much attention to other native shrubs that also have good fall color.

In Colorado, western Colorado at least, our scrub oaks (Quercus gambelii) are a major contributor to our fall color and the hillsides look like Oriental carpets of burnt ochre, sienna, rust and chartreuse.  Some other native shrubs that add to the color palette are the burgundy leaves and stems of red twig dogwoods and gilded willows growing along riverbanks, the rusty reds and oranges of three leaved sumacs and wild roses on the hillsides and roadsides.

Red-twig dogwoods, Cornus sericea, is popular in the landscape industry because of its colorful red or yellow branches make a show in the winter, especially against the snow.  Burgundy fall color is a beautiful contrast under native cottonwoods, along rivers.  In this photo, native virgin’s bower, Clematis ligusticifolia, is growing over it. 

I enjoy our native willows (Salix spp.) most in the late winter/early spring when the sap begins to flow and the stems are the most colorful.  I wish I could paint them.  They are in the Salicaceae family, like aspens and cottonwoods and have similar fall color.

Three-leaved sumac, Rhus trilobata, is also a favorite fall shrub for its varied rusty-red to chartreuse colored foliage.  In the early summer it produces salty-sour fruit that is good for making a lemonade like beverage.  In extreme western Colorado, there is a variety with simple, rather than compound leaves.

Wild roses (Rosa spp.) have similar fall color to three-leaved sumacs and also have colorful red hips that are high in vitamin C and are great for tea and homemade beauty products.

There are more native shrubs that add to our colorful fall, such as barberries (Berberis spp.), currants (Ribes spp.), sometimes snowberries (Symphoriocarpus spp.) and serviceberries (Amelanchier spp.).  Comment on others.

Wednesday, October 7, 2020

Planning and Planting perennials in Fall

Cassey Anderson, Master Gardener Coordinator in Adams County 

This is a great time of the year to get a few new perennials in the garden. As a bonus many nurseries are having great sales at the moment! 

I have been adding new garden bed space and reducing the lawn in my yard. This past spring I mulched with about 6” of arborists chips to prep this bed area (a silver lining to having had to remove many ash trees due to Emerald Ash Borer). This fall I decided that it’s ready to start filling it in. I purchased a Kniphofia flamenco (Red Hot Poker) and a Baptisia australis (False Indigo).

I started by determining where I wanted the plants. When planning locations for your perennials you want to consider the amount of sun that they need and will receive, how you will water them (no plant is xeric in its first year of establishment), and how exposed or protected the area is. In this area I've got drip lines running to each plant although I may run a secondary drip line with in-line emitters as I get more plants in the bed. Each of these plants takes full sun with glee and thankfully that is in abundance in this area! 

Perennials establish best if you bare-root them. This means removing the potting media they were grown in. One of the easiest ways to bare-root your perennials is by soaking the plant in a bucket of water and gently teasing the soil out of the roots. Root washing helps ensure good soil to root contact and plants are more likely to establish quickly than if you leave them in the “cushy” media.

This Kniphofia is nicely rooted and not pot-bound. 

The Baptisia is a little pot-bound but root washing
can rectify this for herbaceous perennials

One of the big differences you find when you bare-root your perennials is that the roots will get very long, so you may need to arrange your holes differently. You can tease the roots out to fill the space in the hole most effectively. That said, if your soil is in good condition you may not need to dig as big of a hole once you wash all the media off your roots.

Look at those gorgeous roots making an appearance!

The roots on the Baptisia were SO long, 
I had to go get a shovel and dig a larger
hole to accommodate them. 

The next step is to dig your holes, loosen the sides of the holes if you have any smooth surfaces from your shovel. There is not need to amend with any organic material unless you plan to amend the whole garden bed. Gently place your plants in the hole and distribute the roots evenly. Cover the roots up while holding the plant up (this takes some more care than with plants that have not been bare-rooted). 

Getting the plant in place, tease the 
roots so they can spread out and 
establish in the soil. 
Start to fill in gently around the
roots with your native soil. 

Finally, you want to water your plants in well over the next couple of days. The warm soils of autumn ensure that you can get some good root growth before the cold of winter really sets in. A layer of mulch will retain moisture for longer and has the benefit of reducing weeds in the area.

It might not look like much right now but I'm hopeful that by next year it will be looking much more filled in.

Cranberry Girdler Rears its Ugly Head

 Posted by: Alison O'Connor, Larimer County Extension

Doesn’t it seem weird that we have a type of sod webworm called cranberry girdler that lives in lawns in Colorado? Because this insect is a pest of cranberry bogs, Douglas-fir, and true fir…along with cool season lawns. Weird.

Regardless of its preferred hosts, these guys can do damage. Quickly. And I’ve seen a number of lawns this fall with damage. For example, there was this lawn in Loveland, which was the worst damage I’ve seen. All of the brown areas are dead. This lawn was a mix of fine fescue, tall fescue, and Kentucky bluegrass.

As for the actual insect, it appears to be a western problem in states like Utah, Colorado, and Wyoming. There’s not a lot of information about it, nor much research. (Utah State University has the best publication.) It’s a sod webworm that does its feeding and damage in late summer into fall. The damage looks a bit like drought stress, until you tug on the grass. Then it peels up like a cheap toupee.

Cranberry girdler can kill lawns by chewing through the roots, resulting in browning and the resulting toupee. Identification of this pest can be hard because it looks like most other sod webworms—grayish, smallish, with an orange-brown head measuring about ¾” long at maturity. The adult is a small moth with three black dots at the base of the wings, a buff color, and measure about ½” wide.

Adult moths (which emerge from overwintered larvae) emerge in mid-June and actively mate for 6-8 weeks. Eggs are laid on turf blades and hatch 9-11 days later. The larvae burrow into thatch or grass crowns, where they feed for two months. And that’s when we start to see damage (August-September).

Adult cranberry girdler moth
Larvae will burrow deeper into the soil when temperatures start to cool. I think that’s why we’re seeing damage so late this fall—we really haven’t had cooler daytime temps, so the larvae were still feeding near the surface and easy to spot in late September.  

Now, you will be hard pressed NOT to find some sod webworms in your lawn, but there is a threshold you should consider before treatment. First, how widespread is the damage? If it’s a significant percent of the overall lawn, then treatment could be considered. Do you have the ability to water in products? If so, then treatment can be considered. But just because you see little white moths flying about doesn’t justify treatment. Many lawns will do well with some sod webworms present—especially those that are properly maintained.

A couple of things about treatment. The first is that if you have damage this fall, you should consider a spring-applied treatment for control next year. A promising (and easily available) product for homeowners is acelepryn, which is found in Scotts GrubEx. Apply this in late May to early June, watering it in with at least ½” of water. This product will control sod webworms and all white grubs (here’s looking at you, Japanese beetle).

But this fall, acelepryn or other recommended insecticides (beta-cyfluthrin, carbaryl, and chlorpyrifos) will not work quickly enough to kill damaging larvae. One of the few options is trichlorfon (sold as Dylox) and can work as a “rescue” treatment. This should be applied by a lawn care professional. Prior to application, water the lawn well with at least ½” of water and after application, apply another ½” of water. While very effective, this insecticide only lasts a couple days, so timing is important. It will not work if the caterpillars have pupated deeper into the soil.

And what do you do with the damaged areas of the lawn? You’ll have to reseed or re-sod. Seeding now (in early October) will not likely be super successful, so waiting until spring would be a better option. You could sod into late fall, as long as you can water.

So chalk it up to another 2020 “kick-you-while-you’re-down” problem. Boo cranberry girdler. Boo.

Friday, October 2, 2020

What is a Pollinator Syndrome?

Posted by: Lisa Mason, Arapahoe County Extension

Colorado has a wide variety of pollinators! This week on Instagram, the CSU Extension Pollinator Committee took over the Colorado Master Gardener account to showcase some of the awesome pollinator species we see in Colorado. Follow us on Instagram and learn more here.  

Speaking of the wide variety of pollinators, let’s talk about pollinator syndromes.

A bumble bee (Bombus sp.) visiting a Shangri-la sage (Salvia moorcroftiana x indica), a Plant Select plant. Photo: Deryn Davidson

What is a Pollinator Syndrome?

In general, research has shown that plants have specific flower traits that attract pollinators, and the plants provide the pollinator with nectar and pollen rewards. These attractive traits can include flower color, odor, shape, and availability of pollen and nectar. Some plants even have nectar guides that are markings showing where the pollinator should go to collect the reward. Different traits will attract different pollinators. Why would a plant evolve with traits to attract pollinators? Because visiting pollinators will facilitate plant reproduction. This relationship benefits both the plants and the pollinators.

For example, bird pollination is called “ornithophily.”  In Colorado, hummingbirds are primary bird pollinators. We know that hummingbirds generally prefer to visit flowers that are red, orange, or white. The flowers tend to be funnel-shaped, hang loosely on the plant, and have plenty of nectar deep in the flowers. For other birds around the world such as sunbirds, honeycreepers, and honeyeaters, the plants tend to have strong perch support for the bird to land. Flowers that attract birds typically do not have an odor because birds don’t need the scent to find the flowers. You might also notice that the flower petals tend to curve outward to make it easier for a hummingbird in flight to drink nectar.

A female broad-tailed hummingbird (Selasphorus platycercus). Note the pollen on her head. Photo: Nancy Klasky

The USDA Forest Service compiled a chart of pollinator syndromes for the major groups of pollinators. 

A wide variety of research is available demonstrating different pollinator syndromes. I want to share two research studies with you.

Darwin’s Prediction of the Long-Spurred Orchid

In the 1860’s, Darwin studied orchids including the long-spurred orchid, Angraecum sesquipedal. He predicted the flowers were pollinated by a long-tongued moth because the flower has a long spur approximately 12-inches long! The nectar sources are located deep in those long spurs. When Darwin received a specimen of this orchid, his wrote, “…good heavens what insect can suck it” (Darwin, 1862b).

At the time, no pollinators had been observed pollinating these orchid flowers. Scientists predicated the pollinator could possibly be the species, Xanthopan morganii, and subspecies, Xanthopan morganii praedicta, commonly called the Morgan’s sphinx moth because they have a proboscis length (tongue-like tube) that averages over 8 inches long. More than 130 years later after Darwin’s prediction, documentation of this moth pollinating the orchid was finally published beginning in 1993 (Arditti et al., 2012). To learn more, I recommend reading this journal article.

Pollinator Syndromes in Columbines

Another research example that we see in Colorado shows that columbines (Aquilegia spp.) have evolved to attract different pollinators depending on their spur length. This adaptation is considered a “pollinator shift” when the plant adapts to the traits of a pollinator (Whittall and Hodges, 2007).
Besides the spur length, note the other traits the columbines show to attract their designated pollinator. Image credit: Whittall and Hodges, 2007

Your Garden and Pollinator Syndromes

If you are looking to plant flowers to attract pollinators, you can use pollinator syndromes as a general guideline, but we recommend doing additional research and reading about pollinator-friendly plants that grow well in your area. For instance, to support pollinators, avoid double flowers. Many double-flowered horticultural varieties typically do not have pollen and nectar available for flower visitors.

Here are some resources for pollinator-friendly plant and habitats:

Arditti, J., Elliott, J., Kitching, I. J., Wasserthall, L. T. ‘Good Heavens what insect can suck it’ – Charles Darwin, Angraecum sesquipedale and Xanthopan morganii praedictaBotanical Journal of the Linnean Society 169, Issue 3, 403-432 (2012).

Darwin CR 1862b. Letter 3411-Darwin, C. R., to Hooker, J. D, 25 January 1862. Available at:

Whittall, J., Hodges, S. Pollinator shifts drive increasingly long nectar spurs in columbine flowers. Nature 447, 706–709 (2007).