CO-Horts Blog

Thursday, June 1, 2023

San Miguel Basin High and Dry Research Garden Best Performing Plants

By Yvette Henson, San Miguel Basin Extension

I first heard about High and Dry Gardens in Colorado in 2003 or 2004 when I was in graduate school at CSU in Fort Collins.  It piqued my interest because my own graduate research was a drought study.  The concept behind High and Dry gardens is to trial plants to see how they perform on little to no supplemental irrigation. 

I got my graduate degree and moved to Norwood, CO in 2006 to work for CSU Extension.  After I discovered that there were several other Extension Offices in the state that had High and Dry Gardens, we planted a High and Dry demonstration garden outside our Extension Office. 

Planting Norwood High and Dry Garden, August 2006

Norwood is a small town on Wrights Mesa, elevation 7020’.  We are in Zone 5.  Our average annual snowfall is 59.6”. Our average annual rainfall is 15.10” and mostly falls in our ‘monsoon’ period of mid-July through August. Norwood, like the rest of semi-arid Colorado, experiences regular drought and subsequent water shortages and restrictions.  It is not uncommon for residents who live outside of the city limits to need to haul water to their homes for household use. 

I cross-referenced the plant lists for High and Dry gardens at Extension Offices in Gilpin, Boulder, El Paso and Custer counties and selected only the plants that were on all plants lists.  Even though High and Dry Gardens do not typically plant only natives, ours did because those were the plants in common on the other plant lists.

Our original site was a large rectangular bed on flat ground.  Our soil was sandy clay loam soil with a pH of 8.4.  We fenced it to keep our deer.  Each year, we timed our planting to coincide with the annual summer monsoon.  Once the plants were planted, they were watered in and never watered again.  In drought years, I did consider applying the average annual rainfall amount but never did.

Norwood High and Dry Garden in June 2009

The original Norwood High and Dry Garden was there until 2019 (13 years) when the area was leveled to build a new sheriff’s annex.  

Norwood High and Dry Garden in Fall 2017 (note there is no fence)

The plants that survived and performed best were mostly shrubs. Following is a list of the best performers.

Golden currants, Ribes aureum.  All varieties of golden currants require little to no supplemental irrigation.  Golden currants are my favorite of the High and Dry shrubs.  They have beautiful golden flowers in spring (some varieties flowers are more fragrant than others), followed by edible yellow, orange or black fruit.  The shrubs end the growing season with deep-red fall color before the leaves drop for winter.

Golden currants 

Mountain mahoganies: Cercocarpus montanus, C. ledifolius and C. inticatus.  Although the all did well, our favorite of the mountain mahagonies was Cercocarpus ledifolius, curl-leaf mountain mahogany.  We had a 6' x 3’ specimen that kept most of its leaves through the winter. 

Curl-leaf mountain mahogany(photo credit Plant Select, Gary Epstein)

‘Baby Blue’ dwarf rabbitbrush, Chrysothamnus nauseosus var. nauceosus, a Plant Select Introduction was my 3rd favorite shrub in our High and Dry Garden.  It grew to a tidy low mound, 12-18” x 3’.  The yellow blooms were welcome late summer color.

Plant Select 'Baby Blue' rabbitbrush (photo credit Plant Select)

Both ‘Kannah Creek’ sulphur buckwheat, Eriogonum umbellatum (a Plant Select introduction) and James buckwheat, Eriogonum jamesii, performed exceptionally well in our garden.  The deer were not able to eat the blooms like in our Plant Select Demonstration Garden because of the fence.  Both buckwheats form a low mat of semi-evergreen leaves that get good fall and winter color.  In spring and summer, the yellow or cream bracts of the flowers grow about a foot above the foliage.

'Kannah Creek' Buckwheat (photo credit Plant Select)

James Buckwheat (photo credit Al Schneider, SW Colorado Wildflowers)

Rocky mountain penstemon, Penstemon strictus, almost ate the garden.  The showy and reliable early- summer blue flowers reseeded prolifically in our gravel mulch!  So, we learned to cut the blooms off to prevent reseeding.   I found this ironic because most gardening books list this plant as short-lived.  Perhaps they are in watered gardens.

Rocky mountain penstemon in Norwood High and Dry Garden (blue flowers)

Other plants worth a mention are pussytoes, Antennaria parvifolia; blanket flower, Gaillarida aristata; and bluemist penstemon,  Penstemon virens.

blanket flower in background, pussytoes in mid ground
 at Norwood High and Dry Garden

The county gave us a new border for a High and Dry Garden in 2022.

Master Gardeners planting our new High and Dry Garden Berms in 2022


Tuesday, May 16, 2023

Why I Garden

posted by: Susan Magill, Colorado Master Gardener, Douglas County

I see my garden as a metaphor for the essential lessons in learning to lead a full and authentic life. My garden is a place where I encounter the creative energies and rhythms of the eternal life force that both bonds me to everything in nature and animates my spirit.

hawthorn flowers
Gardening is a sacred act, a mutual nurturing of human and earth that dates back to prehistoric times. For example, scriptures from the Bible are sprinkled with references to nature as a teacher of fundamental human truths. Ecclesiastes, for example, declares "To everything, there is a season," while Revelation advises: "Hurt not the earth, neither the sea nor the trees." Every religion has its gardens. Gardens relate to something primordial, offering a connection to beauty, mercy, and grace. I need my garden as it needs me, loving its gifts that multiply with my care.

I accept the basic dynamics of the garden. Plants die on me, and they thrive on me. Plants may never talk back, but they inevitably let me know how they feel. There are no politics in a garden, no controversy. My interaction with a plant is a very singular relationship of my own making. In the garden, I explore myself and my creativity, tolerance, madness, obsessions, level of concentration, and my level of caring. There is no competition in my garden, except with myself.

For the most part, gardening is about solitude. Gardening can make solitude feel like solace instead of the prison it might unfortunately be for some. I relish in the constant process of renewal that is always visible among my plants; there is always hope! A magnificent thing about my garden is that it is never, ever the same from one hour to the next. The light, the wind, the angle of the plants' leaves, the energy levels, they're always changing.

forsythia flowers

As a gardener I give up my preoccupations and focus solely on my labor. It's freeing in that respect because I’m concentrating on entirely on tending nurturing and caring for my plants. My head empties out when I garden, and I become nothing but a force of nature. Gardening eliminates a great deal of the turmoil in my mind because it focuses my energy on doing one simple activity

Any bit of insight I find or connection I make to nature's cycles helps me better understand the essential elements of our humanity and my place in the intricate web of life. In the Garden, I meet nature face-to-face with all my senses, all my physical and spiritual muscles. I am open to the unpredictable, available to life, and ready to learn a lesson or two.

Monday, May 8, 2023

From Dirt to Soil

 If you're ever in a room of soil scientists, I would recommend that you think twice before using the word "dirt". Dirt and soil are not the same thing (i.e., dirt is devoid of any life, while soil is teeming with life), and some people will get quite upset if you interchange the two words (for the record, I am not one of these people). Case in point: I happened to meet someone who had gone on a first date with one of my colleagues. He told me that the date was going well, but as soon as he used the word "dirt", my colleague's mood completely changed, the date quickly came to an end, and he never heard from my colleague again. So, if you want to make it to a second date with a soil scientist, make sure you're using the word "dirt" correctly...or maybe just don't use that word at all.

Anyways, perhaps you have a garden that is, quite literally, made of crummy, old dirt. Or, more likely, it's made of poor quality soil. Do you abandon all hope in having a healthy and fruitful garden? Do you scrap your life here and move to the Midwest in pursuit of more fertile soil??? No! There is another way to attain a thriving, productive garden, and that is through the regeneration of your soil. 

Soils can generally be characterized by two things: soil texture and soil structure. Soil texture refers to the proportion of sand, silt, and clay within a soil. This proportion governs the characteristics of a soil, such as its nutrient-holding capacity, drainage rates, and affinity for compaction. I'm sure many of you will resonate with the challenges of highly clayey soils, which are prone to slow water drainage, limited oxygen availability, and compaction.

Unfortunately, there is no practical way to change a soil's texture at scale. The good news, however, is that a soil's innate behaviors can be adjusted by altering the soil structure, which refers to the arrangement of soil particles. Specifically, you want to promote the arrangement of your soil particles into aggregates.

Basically, aggregates are clumps of soil particles that are bound together by organic matter, fungal hyphae, and roots. Not only do they increase the resiliency of soils to disturbance and create microhabitats that support diverse microbial life, but they also help increase water-holding capacity in sandy soils (organic matter acts like a sponge) and increase water/air infiltration in clayey soils (by increasing pore space). 

Conceptual Diagram of a Macroaggregate; Source: Soil Processes and the Carbon Cycle by Jastrow and Miller, 1998.

To increase aggregation in your garden, and thus improve your soil structure, there are several tactics you can take:
  1. Incorporate organic matter into your soils using amendments such as manure, biosolids, plant-based compost, and/or coconut coir. The goal is to reach a soil organic matter content of 5% in your soils (contrary to popular belief, you don't want more than 5%). Take caution if applying organic matter amendments that are high in salts, such as manure and biosolids, as high salts can damage plants and soil structure. Before applying any organic matter amendment, it's best to do a soil test on your garden soils to understand the current levels of organic matter and salts present, which will inform how much amendment to apply.
  2. Grow cover crops when soils are bare (e.g., during the off-season). Cover crops will add organic matter into the soil through their roots, and they can be an additional source of organic matter if the cover crops, upon dying, are left on the ground or incorporated into the soil. Cover crops will also protect the soil from erosion and can add nitrogen into the soil if the cover crop is a legume.
  3. Mulch around your plants. Mulch will conserve soil moisture, help control weeds, and ultimately add organic matter into the soil as the mulch breaks down over time. Organic sources of mulch include wood chips, straw, or grass clippings. If using straw or grass clippings, take into consideration whether any herbicides have been used or if weed seeds might be present.
  4. Reduce disturbance of your soils. While some disturbance may be necessary when incorporating organic matter amendments, frequent or intense disturbances can ultimately degrade soil structure. As a result, consider using less invasive ways of amending (i.e., a broad fork instead of rototilling) and avoid tilling unless you're adding organic matter.
Whether you attempt one of these tactics or all four, remember that it takes time for soil structure to improve. Be patient and diligent in your commitment to regenerating your soils, and over the years you will reap the benefits! 

Have questions about soil regeneration? Ask them below!

Thursday, May 4, 2023

Rabbits, voles, and gophers...OH MY!

Posted by: Todd Hagenbuch, CSU Extension, Routt County

Classic rabbit 'trimming'
of smaller branches

While many of you reading this blog have been watching the daffodils and crocuses bloom for a few weeks, those of us in the higher elevations are just seeing the ground as it becomes uncovered by rapidly melting snow. As the snow recedes, what’s becoming evident is that, at least in Routt County, several types of varmints had a hay-day under the snow and treated our yards as an all-you-can-eat buffet. I’ve gotten many calls in the past two weeks with folks wondering what creature has caused the damage they’re seeing in their yards, pastures, and hay meadows. I also find that people often blame the wrong critter, or have had multiple species wreaking havoc.

Vole damage at the bottom,
rabbit damage above

The first thing we’ve seen as the snow levels dropped is that rabbits dined on several things, especially fruit trees. Lots of folks talked this winter about the number of jackrabbits in the area this year, and mentioned the damage they were seeing to local haystacks. We see now that they were taking advantage of town plants, too, with branches being trimmed and trunks being scalped at varying levels according to the snow level when they came by. I’ve seen several crabapple and apple trees that look to be a total loss due to the rabbit damage they’ve sustained.

As the snow pulled away from the bases of trees, shrubs, and herbaceous perennials, vole damage has come into full view. Have you seen girdling around the bottom of trees, along the soil line? Vole damage. Gnawing marks on the stems of small bushes? Vole damage. Perennial plants that had unexplained chewing at the base? Yep, probably voles!  

Vole damage on lilacs
I had the pleasure of visiting a home that had vole damage on their lilacs and also their fruit trees (see
photos). They still had some small piles of snow near the trees which looked like Swiss cheese, with holes into and out, right in-line with the classic vole ‘runways’ that appeared around the lawn. In fact, as we sat and were looking at the bushes, the little beasties popped their heads out and ran from pile to pile! Little tufts of grass where they’ve disturbed the surface and small holes are other telltale signs that voles enjoyed the warmth and protection of a blanket of snow while feasting on our plants.
Vole damage on apple

The other varmint that had a regular rager under the snow was the pocket gopher. While they live under the soil and dine on roots, the soil they dig out for their subterranean feasts was neatly packed away in tunnels under the snow in long, curing, snake-like piles that are called eskers. People expect to kick at the eskers and find holes or tunnels underneath, but what they don’t realize is that the hole the pocket gopher actually took the soil from is near one end or the other of the esker.

Vole runways in a pasture
Wondering what critter has been decimating your garden? If the explanations here don’t help, check out CSU Fact Sheet 6.521, Burrowing Animals: Determining species by burrows and damage. If you do know which one is to blame and want to know what you can do about it, check out Fact Sheet 6.507 Managing Voles in Colorado, or Fact Sheet 6.515 Managing Pocket Gophers. And don’t forget this next fall to prepare your plants for more damage by protecting them before it snows, too, because these little buggers are looking forward to eating at your place again next winter.
Pocket gopher eskers
in a pasture; courtesy of
Millie Delaney

Tuesday, May 2, 2023

No Mow May? Let's help our pollinators all year!

Posted by: Denyse Schrenker, Eagle County Extension

No Mow May keeps popping up on my news feeds so I decided to do a little digging. The idea is that pausing mowing for a month in the spring gives flowers in the lawn a chance to bloom. The goal behind the movement is to provide floral resources for pollinators at a time they are often limited. I don’t have to mow in May and it helps the bees! Sounds like a win-win to me. 

I started looking into the research often cited as evidence for the benefits of not mowing in May. Although the concept largely gained popularity from a now retracted study, there is some research that shows decreased mowing is beneficial for bees and more broadly, arthropods. It is important to note that these studies did not specifically look at not mowing in May but at a reduced mowing frequency for the entire growing season. A study in Massachusetts found that lawns mowed every 2 weeks had the highest bee abundance compared to weekly mowing and mowing every three weeks, despite the lawns mowed every 3 weeks having the greatest abundance of flowers (Lerman et al. 2018). A meta-analysis looking at the effect of mowing frequency on arthropod abundance and diversity in urban settings found that decreased mowing frequency was strongly associated with increased arthropod diversity and moderately associated with increased abundance of arthropods (Proske et al. 2022). An unexpected but interesting finding from this study was a lower abundance of ‘pest species’ in lawns with reduced mowing schedules (Proske et al. 2022). 
Another consideration is the impact not mowing for a month will have on the health of the lawn (and your lawnmower!). Mowing more than ⅓ of the height of the lawn stresses the grass. While grass may not have grown tall enough in some areas of Colorado for this to be a major concern, in the lower elevations grass will be tall enough that waiting until June to mow could harm the health of the lawn. The flowers often found in lawns, such as dandelions, clovers and black medic, are adapted to mowing and flower under most mowing heights. 

While No Mow May might not be the solution to saving the bees I had hoped for, there are many things we can do to benefit pollinators and the environment. 

Raise your mowing height
  • Try raising your mower height to 3.5, or if your mower allows, 4 inches and mow only as often as needed to remove no more than ⅓ of the grass height at a time. For example, when mowing at 3.5 inches, you should cut the lawn when it gets to around 5.25 inches tall. This management strategy could have the added benefit of reducing mowing frequency throughout the entire season which would reduce your carbon emissions.
When possible, do not bag the grass clippings. 
  • The grass clippings will break down and provide organic matter and nutrients to the soil, reducing the need for fertilizer and increasing the water holding capacity of the soil. This is another possible side effect of No Mow May, the grass clippings will likely be too great at the first mowing to leave in the lawn, and if composting is not an option for you, those clippings are off to the landfill where they contribute to methane emissions. 
Whitney Cranshaw, Colorado State University,
Female Andrenid bee guarding her nest entrance. Whitney Cranshaw, Colorado State University,

Create habitat for native bees
  • A vast majority of our native bees make their nests in the soil. Ground nesting bees prefer sunny, open areas with little vegetation cover so a dense and healthy lawn is not an ideal nest location. 
  • Scout your yard in April for ground nests and flag their location so you remember to leave that area undisturbed until early summer when the bees have moved out. 
  • Leave a sunny area of the yard bare and make sure that area is not under sprinkler irrigation. You can even provide mounds of different types of soil for them to choose their preferred nest building material. 
  • Remove weed barrier and landscaping fabric from the garden as it inhibits ground nesting bees. 
  • Rock walls, a shallow layer of river rock mulch, old stumps and logs, and the stems of native perennial plants are other habitats utilized by some native bees we can incorporate into our yards. 
  • Don’t forget about water! Add a bird bath or other shallow water source to your yard. Keep it filled with clean water and add a few rocks for bees and butterflies to stand on while they drink.  
Use pollinator friendly pest management strategies.
  • Reduce pesticide and fertilizer inputs as much as possible. 
  • Never spray a plant that is in bloom or about to bloom.
  • Always read and follow the label instructions on pesticides, organic or not (it is the law!)
  • Leave clovers and black medic in the lawn, they fix nitrogen and can help lower fertilizer needs.
Replace part of your lawn with a well-designed pollinator garden or a no-mow zone filled with native flowering plants. Lawns generally are not abundant or diverse resources for pollinators and dandelion pollen is a poor nutrient source for bees. Creating dedicated pollinator habitat will provide a rich source of floral resources all season long! Below are a few helpful resources for creating pollinator habitat:

Check out these past CO-Horts blogs to learn more about all the amazing things pollinators do for us and how we can best help them:
CO-Horts Pollinator Blogs. You can learn more about our native bees at Pollinators need our help, luckily there are many steps we can take that have a proven positive impact.


Lerman, Susannah B., Alexandra R. Contosta, Joan Milam, and Christofer Bang. 2018. To mow or to mow less: Lawn mowing frequency affects bee abundance and diversity in suburban yards. Biological Conservation, Volume 221, Pages 160-174, ISSN 0006-3207,

Proske, Anja, Sophie Lokatis, and Jens Rolff. 2022. Impact of mowing frequency on arthropod abundance and diversity in urban habitats: A meta-analysis. Urban Forestry & Urban Greening,

Volume 76, 127714, ISSN 1618-8667,

Wednesday, April 26, 2023

The Curious Incident of the Foam in the Nighttime


Posted By: John Murgel, Douglas County Extension

The recent windy days we had across the Front Range recently made me remember a strange phenomenon from a similarly windy period last fall.  My aunt, an avid water gardener, awoke to find her largest pond--the one with the waterfall--awash in fluffy suds.  It reminded me of when students would pour dish soap into the fountains in college.


Foamy pond

Setting aside such sophomoric stunts in a quiet back yard, what else could be going on?  

Owing to the season, a large number of ripe honeylocust (Gleditsia triacanthos) pods were adorning the local trees, including one in the same yard as the pond.  The wind blew many of them down; they littered the ground.

Beans, water, and foam.  My mind turned to Aqua faba, the vegan foam sensation.  (Aqua faba is Latin for “bean water”—don’t things sound sophisticated in Latin?) I remembered reading a recipe where the water from canned beans could be whipped into a meringue, like egg whites, since the complex sugar molecules leached from the beans could form complex networks similar to the proteins in eggs.  These same compounds are what make certain beans—notably soybeans—a source of emulsifying agents used in processed food. 

 A quick search of published scientific papers showed that honeylocust fruits had themselves been explored as a source of emulsifying agents, though the studies all described variously involved cooking or chemical preparation to extract the desired compounds.  Would soaking in pond water be the same as industrial processing?  Always up for an experiment and with young children to entertain, I set about finding out. 

dry honeylocust pods
wet honeylocust pods

Luckily for me, honeylocusts are common trees.  A quick trip to a front yard down the block provided a shopping bag full of pods.  I dropped some pods into a bucket, covered them with water, and let them sit overnight. Then, when my wife was not home (I don’t think she reads the blog), I got out the hand mixer and got to work. 

 The water was the color of weak tea, and smelled pleasantly floral and a bit like wet leaves.  Something had been extracted, but would it create bubbles? 

honeylocust pods with golden water.


 It took three seconds to fill the bucket with foam.  Three. (If you're wondering, "no, I didn't taste it").

 I can't prove that no one put dish soap in my aunt's pond, but I think the honeylocust pods are a prime suspect for the foam—the overnight soak plus the agitation of the waterfall created the perfect conditions for sudsing.


Foamy honeylocust waterfoamy honeylocust water

The pond-foam eventually subsided on its own, without harming the fish or the plants.  (The primary risk being from the organic matter addition causing a potential drop in oxygen levels--the waterfall aeration was not just a problem-causer here).  

Maybe it was the honey locust trees on campus, too?



Friday, April 21, 2023

Alternative Small Fruits

By Yvette Henson, CSU Extension, San Miguel Basin.

Recently, I was a co-instructor for the Colorado Master Gardener Small Fruits Review. One of my favorite sections to cover is Alternative Small Fruits.

What is a 'small fruit'? The way I understand it is that both the plants and the fruits are generally smaller than tree fruits like apples. Both the apple and the tree it grows on are larger than a raspberry and a raspberry plant, for example. Since there is not a strict definition, the lines can be blurred in a few situations. Other common small fruits are strawberries, grapes, blueberries, blackberries, etc.  I would define an alternative small fruit as a small fruit that isn't commonly grown or sold in grocers.  

The first alternative small fruit I want to cover is black elderberry, Sambuscus nigra subsp. canadensis. (Please take note, that our native, red-fruited elderberry is toxic!)  Black elderberries are hardy (zone 3 or 4) shrubs that produce clusters of cream-colored flowers, followed by clusters of dark-purple fruits.  The fruits are used in pies, jams and jellies.  Elderberry syrup is known to be immunity building.  In the UK, it is popular to make a cordial with the blooms and the blooms can also be eaten in salads or fritters.  It is important to plant more than one for good pollination and fruit set. To prune, cut branches that are 3 years old and older all the way to the ground in early spring. 

Another alternative small fruit known for its antioxidant properties is Aronia melanocarpa, black chokeberry.  These fruits are among the highest in antioxidants among temperate fruits.  They are suckering shrubs hardy to Zone 3 that grow 3-6' x 3-6'.  The white flowers and purple fruit are in clusters.  The fruit are high in tannins and don't taste good unless processed or frozen. They aren't fussy about soil and don't require a lot of pruning.  They are not drought tolerant, requiring more than 15" of irrigation a year.  An added plus is a rusty red fall color on the leaves.

It is very challenging to grow blueberries in Colorado because of our alkaline soils, arid climate and desiccating winds.  A very hardy small fruit we can grow is honeyberry, Lonicera caerulea. The 6' shrubs are hardy to zone 2, and even better, the small pinkish flowers are hardy to -7 degrees F!  The fruit has many uses: eaten fresh, in ice cream and smoothies or jams, syrup, etc.  More than one variety is needed for pollination.  They have few pest problems and are easy to grow.

Goji berries, Lycium barbarum, are another popular 'super fruit' that I was surprised to learn grows in Colorado.  It is an arching shrub-vine that grows to 4'+ and is hardy to Zone 4.  Beware that it suckers and can be invasive if not kept in check!  It has pretty pink flowers that mature to oval orangish red that are most popular dried in trail mix and in teas.

The last plant I want to talk about is Nanking cherry, Prunus tomentosa. It is a tall shrub (15') that is native to China, hardy to zone 2 or 3.  Nanking cherries do well planted in a hedge or windbreak and benefit from cross pollination.  They tolerate dry soil.  The fruit are bright red 'cherries' about the size of the end of your finger.  They have a tart but pleasant taste and can be eaten fresh, if you can beat the birds to them!  They are tasty in pies and jelly.

Let me know in the comments if you grow any of these alternative small fruits in your garden!