CO-Horts Blog

Monday, January 30, 2023

Colorful Winter Stems

by Yvette Henson

Winter can feel so devoid of color.  There are no flowers blooming, the deciduous trees and shrubs are bare.  The grass is no longer green.  But that same grass is now a butterscotch gold against the snow.  The branches of deciduous shrubs sometimes develop an even deeper color in the cold that is unveiled with the loss of leaves.

The following three photos are of various willows that I see along my weekly and sometimes daily drives.  I purposely look for these patches of yellow, peach and red stems- bright pops of color in an otherwise gray and white world.  Willows are in the genus Salix.  I decided not to attempt to identify those in these photos to species-- willows can be difficult and there are no flowers or leaves to help.  

These red, orange and yellow willows grow along
Highway 62 on Dallas Divide, SW Coloraodo

These golden willow trees are on my drive to work
(I don't even notice them in the summer)
These peachy red willows, along this irrigation ditch, 
can grow out of control

Another very popular shrub grown in many gardens all over the world, is red-twig dogwood.  It is popular because of the bright color of the stems, especially against the snow.  We have a native species, Cornus sericea.  It can be found growing on the gravelly banks of rivers. 

Our Colorado native red-twig dogwood
(growing along the San Miguel River in SW Colorado)

Willows and red twig dogwood are riparian plants, which means they grow in wetlands along rivers, streams and other bodies of water.  In the winter it may be difficult to tell them apart.  

red twig dogwoods have opposite stem and leaf arrangement
(side branches grow in the same location on each side of the main stems)

Willows have alternate stem & leaf arrangement
(the side branches originate at different locations along the stem).

What are some plants that brighten up your winter landscape?

Tuesday, January 24, 2023

Repotting an Heirloom Houseplant

 Posted by: Alison O'Connor

Sometimes horticulture can be stressful. That anxious feeling you get when you splurge on a plant that you know probably won't survive in your landscape...or when you sow your seeds, but forget to turn on the heat mat...or when you don't water your houseplants for a month. Or is it just me? A couple weeks ago I experienced the most horticultural anxiety when I repotted a 50+ year old rope hoya that belonged to my Grandma Mae. Grandma Mae passed away right before I moved to Colorado and this hoya lived in her house for decades. It was always dark green and beautiful.

Horticultural anxiety!

This plant means the world to me, and when I moved across the country, it had a prime location in the car, nestled between blankets. Since then, it's happily lived on the hutch in our kitchen, facing east. Well, mostly happily. It needed repotting, something I was happy to ignore for years. Like YEARS. It was growing (kind of)! It was thriving (mostly)! It was green (pale)! But the time came when I couldn't ignore it any longer.

My rope hoya was not a happy camper, but I couldn't bear to repot it. 

With dread in my stomach, I bought new cacti/succulent potting mix, a new pot, and set to work. It was in a tiny clay pot and there wasn't a way to pull it out, so I broke the pot apart with a hammer - gently. It was almost like the plant breathed a sigh of relief when the pot came off. I held the plant in my hands, a matted mess of roots, and cursed myself for not repotting it years ago. 

The root ball is so small! Why did I wait so long?!?

I gently brought it to the sink, hydrated the roots (which seemed to shrink), and prepared the hoya for its new home. A little potting mix in the bottom, tuck the plant in, a little more potting mix, gently press around the plant. I'm fairly certain that my pulse was racing and I barely breathed during the process. Then I returned it to the sink and gave it a good watering. I'll fertilize it in a couple weeks once it gets more settled. 

Happy in its new home. Grandma Mae would be proud.

As of now it's doing fine. I'm hopeful it will bloom again and live another 50+ years!

Wednesday, January 18, 2023

Peppers for your Palate: 2022 Larimer County Pepper Trials

 Posted by: Alison O'Connor and Jon Weiss, Larimer County Extension

Peppers are hot! But also sweet. And the interest in growing peppers has increased in recent years. As most people know, it's tough to garden in Colorado - and having a short list of vegetables that perform well is helpful for all gardeners. In 2022 the Larimer County Master Gardeners, led by Jon Weiss, conducted an extensive research trial to evaluate bell peppers and sweet lunchbox types. Jon and "Team Pepper" grew 15 different types in a replicated, randomized trial.

Larimer County Master Gardeners: Team Pepper! 

Hybrid and open-pollinated pepper varieties known to be early to earlier mid-season in maturity were selected. Twelve varieties were sweet bell peppers and three were “lunchbox” type. The peppers were started from seed in the CSU Horticulture Greenhouses and transplanted in early June at the CSU ARDEC-South (Fort Collins, Colo.) research farm. Seedlings were planted into ground beds covered with black plastic and irrigated with drip irrigation. 

Planting peppers on June 9, 2022 at ARDEC-South.

Fun fact: even research plants aren't immune from rabbit munching. Boo. Something to work on for next year.

There were three harvests during the growing season, just as the fruit on the plants started to color. Fruit was counted, weighed, and the number of lobes on each fruit determined - for those who want to grow peppers for stuffing. At the end of the growing season, fruit was tasted by a brave group of 16, ranking each pepper from 1 (meh) to 5 (super tasty) based on sweetness, texture, and overall flavor.

Weighing and counting 'Eros' peppers.

While 'Purple Beauty' set fruit and colored first, the flavor was poor. 'Olympus' and 'Ace', both bell peppers, yielded the greatest number of fruits ('Ace' had an average of 26 fruits per plant; 'Olympus' had 16 fruits per plant). 'Olympus' also yielded the greatest number of four-lobed fruits for stuffing. 'King Arthur' ruled supreme with huge fruits, averaging about one-half pound each! 

For flavor, yield, and slightly larger fruits, 'Just Sweet' ranked at the top of the lunchbox types. 'Cajun Belle', toted to have a "slightly spicy flavor" was hotter than expected - and it was not included in the taste test. If you just want a lunchbox pepper with loads of fruit (an average of 74 per plant), grow 'Eros'. You'll pick for days. All the fruit in the trial was donated to local food pantries, about 500 pounds.

Peppers headed to local food pantries.

Full results can be found on the Larimer County Extension website. You may also download or print the PDF here. The website also has results from the 2019-2021 tomato trials. The pepper trial will be replicated in 2023.

Wednesday, January 4, 2023

Meant to Bee: Overwintering Strategies for Bees

Posted by: Lisa Mason, Arapahoe County Extension

Where do the bees go in the winter? With over 900 species of bees found in Colorado, it is an interesting question. How do they survive the snow and cold temperatures? Can we support bees during the winter? Bees and other insects have special adaptations so their species survives from year to year. Here is a look at bee adaptations and life cycles in the winter time.

Honey bees

Honey bees (Apis mellifera) are one of the 900+ species of bee in Colorado. They have a eusocial structure meaning the colony has: 1) overlapping generations, 2) a reproductive division of labor, and 3) cooperative care of the developing larvae. The female worker bees forage all summer and into fall bringing in food reserves to last them the winter. When temperatures start to drop, honey bees huddle together to make a cluster and shiver their wings. Shivering provides warmth for the hive. Their main goal is to keep the queen warm so the colony can survive. The core temperature in the hive can be as high as approximately 91 degrees Fahrenheit. A healthy hive with adequate food storage is more likely to survive, which reinforces the importance of best beekeeping practices by the beekeeper all year. Read how to prep a hive for winter here. When a beekeeper harvests honey, they have to be careful not to harvest too much. Beekeepers should leave 80-100 pounds of honey in the hive for the bees to feed on throughout the winter. Honey bees are often seen outside the hive warm winter days. Anytime temperatures rise above 55 degrees Fahrenheit, honey bees may take a cleansing flight which provides them the opportunity to relieve themselves. Honey bees may also forage for whatever they can find including tiny bits of protein at bird feeders.

The worker bees in the hive cluster around the queen during the winter to keep her warm and safe. Credit: Lisa Mason

Bumble bees

Colorado has 23 species of bumble bees (Bombus spp.). They live underground or in large cavities. They have a one-year life cycle, like solitary bees. They have a social structure within their colonies that include a reproductive queen and workers. Like other social insects, they have overlapping generations and cooperative brood care in the colony.

Newly mated queens are the only bumble bee survivors during the winter. The hardy queens find a place to hibernate in a protected place like leaf litter, a wood pile, or underground. When spring arrives, the queens will emerge, begin to forage, build a new nest, and lay eggs. The eggs will mostly be female worker bees at the beginning of the season. The queen will continue to lay eggs throughout the season. In late summer, new queens and male bumble bees will hatch and leave the colony to find mate. As temperatures drop, the colony from the current season will end except for the mated queens that will hibernate. Queen bumble bees are capable of living alone, unlike honey bee queens.

A queen bumble bee (Bombus nevadensis) foraging on Rocky Mountain bee plant. Photo: Lisa Mason 

Solitary bees

Solitary bees comprise of the the vast majority of bee species diversity. They live a one-year life cycle. During the life cycle, a female bee builds a nest underground or in a cavity. A cavity usually consists of a pre-existing tunnel. Some tunnels might be in a dead log, nooks and crannies in stone or brick, a human-made bee hotel, or hollow stems. The female bees collect pollen and nectar to bring back to the nest. All the collected pollen and nectar is made into a ball called “bee bread” which is all the food needed for one bee to grow from a larva to an adult. The female lays an egg on the bee bread and seals up the nest. After the egg hatches, the larva will go through full metamorphosis from a larva, to a pupa, and on to an adult before emerging from the nest the following season. The lives ended for the female and male solitary bees we saw flying around the previous summer, but their brood is warm for the winter deep underground or in a cavity. 

An underground, solitary bee nest (Agapostemon sp.). Photo: Rachelle Stoddard

Does “leaving the leaves” support the overwintering bees?

Leaf litter supports hibernating bumble bees by providing them a sheltered area for the winter. Solitary bees are well-protected in their underground or cavity nest but leaf litter may provide some insulation for their ground nest. Since honey bees live in hives, they don’t rely on leaf litter but they have been observed drinking water from damp leaf piles. Leaf litter also supports a wide diversity of arthropods by providing shelter during the winter. Wooly bear caterpillars are a great example of a moth that relies on leaf litter. They overwinter in the caterpillar stage by hibernating in leaf litter. They have an impressive adaptations to survive the winter. When summer arrives, they complete metamorphosis and transform to an adult Isabella tiger moth. Overall, leaf litter can provide a shelter for a diversity of overwinter arthropods. Leaf litter is also a great mulch for perennial and vegetable gardens. The leaves also return critical nutrients back to the soil. While leaf litter is a valuable component to the landscape, it is important to remove leaves from the lawn to prevent mold and disease growth, and to avoid smothering the turf.

When should spring garden clean-up begin to best support the overwintering bees?

Different bee species emerge at different times, so it is a challenge to find a perfect date for spring garden clean-up that supports bees. Here are some general considerations for supporting overwinter bees:

  • Bumble bees typically emerge from hibernation between mid-April and mid-May depending on weather and elevation. Bumble bees could be impacted if leaf litter is disturbed before they emerge.
  • Some solitary bees nest in hollow or pithy stems such as Rubus spp. (raspberries, blackberries, etc.), joe-pye weed, bee balm, etc. They will emerge in the spring. If hollow stems appear to be plugged, perhaps consider leaving them stems until they emerge, or stems could be carefully moved to a protected location where they won’t be disturbed.
  • Leafcutter bees are often some of the latest emerging bees. They nest in a wide variety of cavity locations from natural spaces to human infrastructure (e.g. patio stones, and occasionally even inside gardening gloves). Since they emerge later in the season, it is likely best not to postpone garden work for leafcutter bees unless specific locations of nests are known that could be protected.
  • Squash bees may nest in underground areas where squash and pumpkin plants are typically planted. Consider not tilling the vegetable garden to support these important pollinators.

  • All bees need early-season flowers that offer pollen and nectar. Consider adding plants that flower as early as April and May. Some options include golden currant, chokecherry, crocus, and pasque flowers.
A leafcutter bee (Megachile sp.) nest found inside a garden glove. Credit: Nicole Didero

More information

For more information on bee lifecycles, check out the Native Bee Watch Citizen Science Field Guide. Learn more about the 900+ native bee species in Colorado by checking out A Beginner’s Field Guide to Identifying Bees

For more information on what happens to other insects in the winter, refer to this CO-Horts Blog post written by Jessica Wong