CO-Horts Blog

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!

Monday, April 17, 2023

Perennial trials reveal top 9 performers in Rocky Mountain conditions by Jim Klett

 After three seasons growing in the challenging conditions of the Rocky Mountains, nine perennial plants have been named “Top Performers” by researchers at Colorado State University.

The purpose of the trial garden is to evaluate new perennial plant species and cultivars under the unique Rocky Mountain environmental conditions. Plants are evaluated for plant vigor, uniformity, floriferousness and tolerance to environmental and biotic stresses. The Perennial Trial program at Colorado State University is designed to test newer perennial cultivars that have been introduced in the past three years or less. Entries in this trial are grown for three summers and two winters before they are switched out for new entries.

Performance Evaluation

Photos and data on plants and flowers were collected on a bi-weekly basis from May to early October. Dead plants in the trial were not considered in the bi-weekly evaluation; thus, the ratings given only reflect the live plants. Members from the Perennial Trial subcommittee also evaluated and wrote comments for each plant variety in June, July, August and September. Plants and flowers were rated 0-5 using the following scale:

2022 CSU “Top Performer” Perennials

Armeria Dreameria® ‘Dream Clouds’ from Darwin Perennials

Heavy first flush of pure white flowers gives a crisp, impressive appearance with plenty of “Wow!” from visitors. The pom-pom flowers give a unique appearance and form for the garden. Growth habit is very uniform and tidy, dark green foliage is attractive even without flowers.


Leucanthemum Sweet Daisy™ Rebecca from Dümmen Orange

Plants were “right in your face” at peak bloom as they formed a solid canopy of flowers which was quite spectacular. Blooms were stunning white with multiple layers of petals and a yellow eye for maximum show. Petals had a very frilly edge and this was definitely not your average Shasta daisy. Plants had a compact and tidy growth habit.

Phlox paniculata Early® Magenta from Dümmen Orange

Compact, uniform plants almost resembled a wall of solid magenta flowers. It was noted for its ability to bloom early and stay late into the season. It also provided a good show of flowers the first year it was planted in 2020. It was resistant to powdery mildew.

Phlox paniculata Ka-Pow® White from Darwin Perennials

The season of bloom was noted for being exceptionally long as it flowered early and stayed attractive for a long time. Plants were compact, uniform, sturdy and maintained excellent habit despite overhead watering. Branching was very good which created an abundance of crisp, white flowers that were very showy. Foliage was very attractive and never had any powdery mildew.

Phlox subulata Spring® Blue Improved from Dümmen Orange

Flowers made an impressive carpet of blue in the spring. The season of bloom was noted for being exceptionally long lasting but the plants were also noted for looking good all through the summer. The growth habit makes an excellent ground cover and spreads evenly.

Rosa Petite Knock Out® ‘Meibenbino’PP 11,252,928 from Star® Roses and Plants

This rose is in a class of its own with very beautiful, glossy foliage and petite growth habit. Flowers had a dark, saturated red color that made a striking combination with the glossy, dark green foliage. The petite growth habit created and overall appearance that easily was described as “adorable”. Besides the impressive appearance, it was also noted that it was very low maintenance and had good first year flowering back in 2020. It could be great addition to containers on the patio as well as in mass plantings in the ground.

Salvia Midnight Purple and Midnight Rose from Dümmen Orange

Both entries had prolific flowering at the same time and complemented each other well. Growth habits were very uniform with the same height. Both plants had very intense, attractive flower color but the stems on both were noted for being dark that really helped make the flower color “pop”.

Thermopsis lupinoides (Golden Candles) from PlantSelect®

At its peak, it was described as a “jaw dropping, showstopper, 50mph plant” due to its prolific, stunning yellow blooms. In addition to its robust flowering, it is a tough plant that is hardy to Zone 3 and drought tolerant for the xeriscape garden. The lupine-like foliage is lush and attractive along with being a good nitrogen fixer for the soil.


Thursday, April 13, 2023

Corn that can feed itself?

Recently during a late night deep dive into YouTube, I stumbled across a video from the BBC. The video was highlighting a type of corn, Sierra Mixe, that we don’t have here in North America. This corn, the video proclaimed, was able to fix its own nitrogen. My poor husband had to listen to me rambling and pondering how this could possibly happen, that it couldn’t happen, only legumes are able to fix atmospheric nitrogen into a plant-available form, right? Turns out this talent is NOT exclusive to legumes as I’ve always thought.

The video did explain that this corn, a different, taller, and longer growing variety than that we grow here, uses bacteria much like legumes. The plant produces a gel-like substance surrounding aerial roots that grow up on the stalk of the corn. The conditions have to be right for the gel to develop but the corn can, indeed, fix its own nitrogen for use in growing.

Image from:

So of course, I began to do some furious googling, to see if this was just an isolated oddity and found that there have been research trials underway since the early 2000s to begin to trial this genetic cross and bring it into commercial production.

It turns out that the gel the roots produce creates just the right environment (complete with no oxygen and lots of sugar) to attract nitrogen fixing bacteria. The bacteria takes Nitrogen from the air (N2) and converts it into ammonia, nitrates or nitrites. The corn can pull the now plant-available nitrogen into its system, some evidence shows that this system can produce 30-80% of its own Nitrogen needs. Researchers are looking at using similar modes of action for other grain crops.

This could prove advantageous for many of our crops that require substantial nitrogen for successful crop growth. Supplemental nitrogen, often synthetically produced, has used 1-2% of the world’s energy and uses greenhouse gases to do so. This same nitrogen, if over applied can run into waterways and create algal blooms which kill off native populations. Wouldn’t it be amazing if we could tweak the growth patterns of many of our crops, so they can produce even some of their own nitrogen?

For more details and information check out:

Posted by: Cassey Anderson, Adams County Horticulture Specialist

Monday, April 10, 2023

Did You Know Who Coined the Term "Nativar"?

 Posted by: Linda Langelo, Horticulture Specialist, Golden Plains Area Extension

                                                Photo Credit: Wikipedia

Allan Armitage, author of Armitage's Garden Perennials, horticulturist and 
professor at Georgia University coined the term "nativar" "to show customers
that the industry was offering what they wanted: garden plants developed
from documented native sources, known in the scientific community as 
genotypes" from "What's in a Nativar?" by Carol Becker. A nativar is a
cultivated variety of a native plant that some ecological value in the 
environment. Nativars can be a native plant that is a genetic variant found in 
nature. That plant is then selected and propagated to retain a particular or 
unique aspect. Nativars can also be obtained through the process of artificial
selection in which plant breeders grow plants with desirable characteristics and
eliminate those with less desirable characteristics according to

According to Ryan McEnaney, Bailey Nurseries' Communications and Public
Relations Specialist, "Nativars allow us to retain the ecological benefits of native
species while making them adaptable and accessible for a modern landscape.
Whether that means a more compact size, cleaner foliage, better color, or a tidier
appearance, nativars solve problems that can arise with the genotype." At your 
nurseries and greenhouses, you may be finding more compact sizes of favorite
native plants with bigger blooms and better color with more disease resistance.

The next question is to plant or not to plant? According to Mary Phillips of the
National Wildlife Federation, it is good to plant 80% native plants and 20% 
cultivars or nativars so that specialist feeders still get what they need to survive. 
Doug Tallamy, American entomologist, ecologist,conservationist and author 
recommends that using  70% native plants and 30% cultivars or nativars is good.
Though Phillips and Tallamy might differ in percentages, the higher the percent 
of native plants the better. 

Let's look at Echinacea purpurea 'White Swan' for a moment. It is a nativar
because it is a cultivated variety of the native species with a white flower. It
is a plant that lives a long time. Another new nativar of Echinacea is
'Snow Cone' another white flowering coneflower with a compact size 
up to 2 1/2 feet for the front of a perennial border. With Echinacea 
alone there are many new nativars to choose to add to your perennial areas. 

                                            Photo credit: Mt Cuba Center

With some nativars, they will feed the indigenous pollinators while being 
resistant to fungal issues, disease and insects. The cultivated plants 
have larger, more color-saturated corollas which are more enticing to 
insects and hummingbirds according to Catherine Winter of in her article, "What are Nativars and Are They 
Beneficial or Detrimental?"

The key to a healthy landscape is the same thing the doctor might say to 
you about moderation and balance in your diet. (Too bad chocolate 
isn't a vegetable.) Apply that in the landscape. Doing so brings about
diversity. If you have all lilacs and daylilies, if a disease or an insect
comes on your property and attacks the daylilies, then you have lost
a great deal of your landscape. Using a variety of plants keeps your 
landscape healthy. Every plant has a purpose and a place.