"Top Performer" Perennials from the 2020 CSU Perennial Trial

Posted by Jim Klett, Professor, Colorado State University, Department of Horticulture and Landscape Architecture

Evaluating perennials in the Rocky Mountains

The purpose of the Perennial 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:

 0 = Dead/No flowers

1 = Poor: Plants are very sick or dying, extremely few flowers

2 = Below Average: Plants are unattractive in some form, i.e. – leggy growth habit, chlorotic or low vigor, flowers are few and occurring sporadically

3 = Average: Plant appearance with growth characteristics that would be expected for the time of season; flowers would be few but uniform across the plants

4 = Good: Plants look attractive (foliage, growth habit, etc.,); flowers are blooming strong and showy

5 = Excellent: Plants are very healthy and uniform; flowering is impressive

 

Selection of “Top Performers”

On November 20, 2020, a conference call was convened with CSU staff and the Perennial Trial Garden Subcommittee. Pictures of entries from the 2018 planting were posted to the Perennial Trial website for review. Data from the growing season was compiled and emailed to each evaluator prior to the conference call for review. After discussion and looking at the pictures taken throughout the season, each plant was voted on by each member of the committee as to whether it should be awarded the designation as a “Top Performer”.

2020 “Top Performers” from CSU Perennial Trials

 

1.    Allium ‘Summer Beauty’ (Allium lusitanicum) from Stonehouse Nursery, LLC

     Soft lavender blue flowers were prolific and brought strong flower power later in the summer. Flowers were relatively tall and held above foliage for maximum show but had good structure and did not lodge. Plant were uniform and very attractive with glossy green, flat leaf blades.

 

2.       Echinacea ‘Sombrero® Tres Amigos’ (Echinacea x hybrida) from Darwin Perennials

Flowers were unique with an “evolution of color” that resulted in about three different shades of color during the season. Blooms were vibrant with a rich saturated color. Abundant flowers remained in bloom a long time and created an impressive overall show. Plants had a good growth habit with strong branching and no disease.

 

3.     Penstemon ‘DAKOTA™ Burgundy’ (Penstemon digitalis) from Terra Nova Nurseries

Dark burgundy foliage was a key reason for the superior rating. Multiple shades of            burgundy added interest to the dark foliage and help make the white/lavender flower color really stand out. Blooms are very prolific with a long flowering period. It was noted that although the flowers are very impressive, the plant looks very showy even when not in flower due to the attractive dark foliage that remained clean all season and never had got “floppy ear”. Plants were very reliable and had 100% survival over three seasons.

 

4.     Phlox ‘Ka-Pow®’ series (Phlox paniculata) from Darwin Perennials

     Evaluators were impressed with the entire series as all had similar height, were very uniform and resistant to powdery mildew. Flowers had a long period of bloom with no color fade. Series had a range of colors that went from soft lavender to a vibrant pink. The pink entry was noted to have some shades of coral which is unique to Phlox.

 

5.     Salvia ‘Blue by You’ (Salvia nemerosa) from Darwin Perennials

      Vibrant blue flowers were very showy with prolific amounts of blooms early in the season and an impressive repeat later in the season after a hard cut back of old blooms. The unique blue color is a great addition to the pallet of Salvia colors in the trade and evaluators said they “had to go see it” from across the garden.

Native plants for winter interest- lesser used edition

 By Irene Shonle, CSU Extension, El Paso County

With climate change creating warmer, drier winters, Colorado gardeners can't rely much on a snowy landscape to hide a garden that has lost its summer pizazz.

This post is devoted to native plants that seldom make the winter interest lists, but will help make your yard maintain some flair during the dullest time of year.  Not only that, but they are also waterwise stars -- we are also experiencing hotter, drier summers, and need to consider our overall water use directed towards landscapes.

                                               

I am  in love with yuccas. Their spiky leaves look fantastic all winter, and there is the added bonus of white stalks of flowers in June.  If you do get snow, the drama only increases:

I 

Most woody sages keep their leaves all winter.  Western Sage (Artemisia tridentata looks great, as does the smaller Artemisia bigelovii pictured above).

Prickly pear cactus (Opuntias) maintain a solid presence throughout the winter.  Some even turn purplish in the winter.  And, of course, in the summer they produce beautiful flowers beloved by bees. And, often, showy fruit in the fall.

                                Opuntia spines can look fantastic in low-angled winter light.

                        A plant I have often overlooked is the humble four-winged saltbrush (Atriplex canescens). It keeps its gray-green leaves in the winter, and the female plants produce interesting seed pods that persist into the winter.

                                Broom Snakeweed (Gutierrezia sarothrae), in my opinion, is a much under-utilized                                     plant. It has tidy blooms of yellow in the fall (appreciated by pollinators), but then in the                                 winter, the seed heads dry out to created a charming presence. A bit like a rough-                                        around-the-edges baby's breath.

                                    Winterfat (Krascheninnikovia lanata) is a much under-utilized shrub. It is extremely         waterwise and provides food for many bird species, including  horned lark, Brewer's sparrow, sage             thrasher  black-throated sparrow, loggerhead shrike, and other birds.  Not only that, but it keeps its narrow, grey-  green leaves in the winter, and the seed heads look wonderful in the morning light.

Here's a plant I did not expect to put on this list, but I am taken with how the seed heads persist into the winter, providing interest and seed for birds.  This is hairy golden aster (the extremely variable Heterotheca villosa).

Consider planting some of these plants in your garden in a sunny dry area, and reap the rewards of providing habitat as well as winter enjoyment.

Your Pollinator Book List: Ideas to Read this Winter and in 2021

Posted by: Lisa Mason, Arapahoe County Extension

Now that we have put our gardens to bed for winter, it is time for rest and downtime. For some, it may be time to plan our gardening activities for 2021. For inspiration, look to the tiny critters that are responsible for pollinating plants in ecosystems around the world and providing healthy foods for people and animals. Your knowledge and appreciation for these hardworking bees and other pollinating insects will blossom.

Here are some of my favorite books on pollinators:

The Forgotten Pollinators by Stephen L. Buchmann and Gary Paul Nabhan, illustrated by Paul Mirocha

Published in 1996, this book is as timely as ever. Written by scientists, this book is filled with stories, research. I think the authors do a great job at painting the picture of different pollinators and their plants in ecosystems around the world. I keep this book on my book shelf and each time I re-read sections, I develop even more appreciation for our pollinators and plants.  

The Bees in Your Backyard: A Guide to North America’s Bees by Olivia Messinger Carril and Joseph Wilson

This book is a fantastic resource to learn more about the 4,000+ bee species found in North America! The book is organized by the different families and genera of bees. It is an easy-to-understand way to learn about the natural history of the bees, identification tips from eye-level to a microscopic level, and includes excellent photos. If you are interested in learning more about bee that may be visiting your garden or if you want to participate in the Native Bee Watch Community Science Program next summer, this book is for you! 

Attracting Native Pollinators by the Xerces Society

Are you thinking of adding more pollinator habitat to your yard? Or maybe you’re interested in adding pollinator-friendly plants at a local community garden? This is a great book that covers the biology and natural history of bees, butterflies and other pollinators. You will also find resources, tips and ideas for building pollinator-friendly habitats in backyards, community gardens, urban green spaces and more. The book also includes plant lists and sample garden plans. Attracting Native Pollinators is another great staple to have on your book shelf.

Our Native Bees: North America’s Endangered Pollinators and the Fight to Save Them by Paige Embry

You will enjoy reading this book to learn about the natural history of native bees. The author does a great job at telling the story about why native bee are so important. You’ll read about the story of the possibly extinct Franklin’s bumble bee, how blue orchard bees pollinate fruit orchards, the secret life of small carpenter bees (Ceratina spp.), and more.

Field Guide to Butterflies of North America by Jim P. Brock and Kenn Kaufman

This guide is a great reference for improving your butterfly identification skills. The book includes great pictures, range maps and includes larval plant food. If you are interested in finding a list of butterflies and moths in your county or state, visit Butterflies and Moths of North America.

The Beekeeper’s Handbook by Diana Sammataro and Alphonse Avitabile

Interested in beekeeping but not sure where to begin? Or maybe you want to learn about the fascinating biology of a social insect? This book will give you the biology and best management practices of keeping honey bees. The decision to keep honey bees should not be taken lightly. In addition to time and money, hives also need to be managed properly to reduce chances of pests and diseases, which not only hurt your hive, but can also hurt other hives in the community. This book is a great tool if you’re a new or seasoned beekeeper.

Some of the great pollinator books on my book shelf!

Many more pollinator and beneficial insect-related books

While the books listed above are some of my favorites, this not an all-inclusive list. Here are some other books that I plan to read soon:

Buzz, Bite, Sting: Why We Need Insects by Anne Sverdrup-Thygeson

The Garden Jungle or Gardening to Save the Planet by Dave Goulson. Check out other books by Dr. Goulson here.

Honeybee Democracy by Thomas D. Seeley

What are your favorite books on pollinators? What are you planning to read this winter? Comment below!

Please note the link for each book directs you to the author’s website or the company that published the book. All these books can be found at a variety of places including local bookstores. No endorsement of products mentioned is intended nor is criticism implied of products no mentioned.

Feeling Thankful in 2020

 Posted by: Alison O'Connor, Larimer County Extension

Don't get me wrong--it's been a hard year. There have been many challenges, new stresses, obstacles, and uncertainty. "Be flexible" has been a good mantra. Despite the bad, there's also been a lot of good. So let's take a moment to reflect on the positives...

People started gardening.

We were stuck at home, looking outside at our landscapes, so people picked up a shovel and got busy. This meant record-breaking seed sales.  Baker Creek, a supplier of heirloom seeds, reported over 10,000 orders on one day in late March. In some cases, this meant packing and shipping delays. It also meant that some seeds were completely sold out. For those of us in horticulture, the news was exciting! New gardeners! (And truth be told, it also provided us Extension folk a bit of job security, since we knew these new gardeners would have questions.) The record seed sales also extended to nurseries and greenhouses, who struggled to keep plants in stock due to demand. 

Shoppers at Fort Collins Nursery (Fort Collins, Colo.) (photo courtesy of The Coloradoan)

Several garden centers reported higher-than-normal Mother's Day sales, with customers swarming to buy hanging baskets, annuals, and summer-blooming bulbs. Signs were posted that said, "New shipments are on their way!" Garden centers responded with curbside pick-up and online ordering. For months, one of the nurseries in Fort Collins had long lines lining the frontage road in front of their store the moment they opened each day. A warm welcome to all of our new gardeners!

Gardeners gave back to their community.

The CSU Extension Grow & Give project provided resources for people to grow produce with the intent of donating some of it back to their communities. Wildly successful (and award-winning!), this project was adopted by 37 Colorado counties. Gardeners donated more than 46,000 pounds of fruits and veggies to local food banks and pantries, as well as churches, community groups, and neighbors. 

Farmers' markets were successful

Nationally, farmers' markets were deemed as "essential business", meaning that they were allowed to operate as per health department regulations. The Larimer County Farmers' Market, operated by CSU Extension in Larimer County, scrambled to open their doors in May. Despite numerous regulations and mandates, the market operated successfully for 24 weeks. It even had the highest sales day in its 45-year history in August. Masked customers lined up obediently, six feet apart, to purchase their favorites from dedicated vendors. Hand sanitizer, wash stations, gloves, and masks all became part of the market culture. 

Styria Bakery II at the Larimer County Farmers' Market (photo courtesy of Karen Collins)

Selling plants to get a home

I recently read this heart-warming story that brought tears to my eyes and provided the hope that we're so desperate for. Aaron Moreno, a California first grader whose family was homeless, sold plants to help his family get an apartment. His mom gave him her last $12, which he invested in succulents and sold them for a profit of $4. He took that money and reinvested it into buying more plants. Setting up his table outside a shed, where the family was living, people bought the plants--in droves. Aaron's Garden raised enough money (with the help of GoFundMe) to move his family out of the shed into an apartment. Aaron now has money in the bank and a place to do homework. While he may not stay in horticulture (he wants to be a judge), it's clear that gardening changed his family's life. 

Aaron Moreno of Aaron's Garden (photo courtesy of @aaronsgarden on Instagram)

Yep. It's been a tough year. But there's still so much good. And if tough times have proven anything before, it's that we'll get through this. Together. Happy Thanksgiving to you all.

8 Ways Cover Crops Can Improve Your Garden Patti O’Neal Jefferson County Horticulture and Urban Food Systems Cover cropping, a strategy also known as green manure, has been practiced by gardeners and farmers the world over for over 10,000 years. This organic restoration practice can boost your garden noticeably the very first year you incorporate it into your own best management practices and the improvements increase even more each year as their effects accumulate. These crops are easy to use, do not need much care beyond watering and a mowing or two and provide tremendous advantages to the garden and gardener. Cover crops are plants that are considered soil builders. Here are 8 sometimes overlooked ways that cover crops build the soil productivity in your garden: ·       Provides Beneficial insect habitat – pollinators, honeybees, beneficial predator insects will all enjoy the nectar as well as the shelter these crops can provide at every season you use them.  ·       Smothers weeds and suppresses their seed from germinating as well.  They provide a dense mat to keep the light from reaching the seeds. ·       Better, more complete soil tillage than any mechanical method.  These crops improve soil structure, allowing more air and water penetration. They can break up soil compaction, loosen tight, hard, or heavy soils and create good tilth. ·       Provides shade for the soil for cooler root temperatures, less moisture losses during hot weather. ·       Acts as a living mulch when established between vegetable rows.  ·       Increases organic matter in the soil while feeding the microbes, beneficial bacteria, fungi, and earthworms living in the soil. ·       Conserves soil moisture both at the surface of the soil and in the critical root zone. The extensive root systems conserve soil by reducing erosion from rain by slowing water flow across and through the soil. The living foliage can also buffer wind effects. ·       Fixes nitrogen from the air while recycling nutrients, preventing their run-off and leaching from the root zone, simultaneously bringing up deeper nutrients to plant roots that are usually unavailable. Use seasonally appropriate cover crops.  Legumes, vetches, rye, and buckwheat are all excellent cover crop plants.  Like all plants, each cover crop germinates and flourishes best in certain seasons. Most reputable seed companies will sell individual crop packets or recommended mixes appropriate for specific season plantings.  Some cover crop seeds are available locally, but seed catalogues have the widest range and generally provide good advice and instruction on using them.

 

                        Buckwheat flowering in  Betty Cahill's raised beds

If you are letting a bed or area of your garden go fallow for a season, this thousands year old practice of planting a cover crop can help to replenish the biological community of your soil below while providing nectar as well as shelter for pollinators and beneficials above. Here are a couple of tips to help you be the most successful with a green manure crop.   

·       Allow your crop to flower but watch carefully and do not let it go to seed or you will be battling weeds of a different sort in the months to come. 

Flowering red clover

·       If you plant early enough in the season you can get one or maybe even two mowing’s in (If you garden in raised beds, a weed whacker works great for this) forcing the root material into overdrive to produce another above ground crop.  This action forces the root system further into the soil to depositing additional nutrients while continuing to improve tilth, bringing formerly unavailable nutrients up to the plant root zone. 

After your final mowing, fork the remainder of the material under so the microbes and arthropods you have encouraged can break it all down completely to become plant available nutrients.  Be sure and do this at least a month to six weeks before your intended planting date for this bed.  Otherwise, the increased microbial activity will compete with the root establishment of new plants or can even disrupt germination of seeds. You do not want to spoil all the good work you have done. 

Farris helping to turn the cover crop

Overwintering Perennials in Containers

Posted by Sarah Schweig, Broomfield County Extension

You may have perennials in containers rather than in the ground for a number of reasons. Perhaps you incorporated them into patio plantings, or maybe they were bought with the intention of planting them, but you didn’t get around to it. Either way, you’ll need to protect most containerized perennials if you want them to survive the winter. 

The USDA Plant Hardiness Zone on your plant tag is based on the plant’s ability to survive winters in the ground, and if you want to rely on hardiness zones, you should look two zones colder than your area when considering plants in containers. For reference, we are Zone 6a here in Broomfield, based on average minimum temperatures from -10ºF to -5ºF annually. For two zones colder, think more like parts of Grand County or Park County in Zone 4a, which has average minimum temperatures of -30ºF to -25ºF. Add the fact that hardiness zones are based on 30-year averages (would anyone classify Colorado weather as predictable?), and it’s important to note that even plants rated for two zones colder are no guarantee for winter survival in containers. That said, there are strategies for protecting your perennial containers, and the more hardy the plant, the better their chances of survival.

 

By digging containers into soil, you can get the same insulative protection for roots that they would get if planted in the soil. Water plants before setting in the ground, and dig holes deep enough for plants to sit at the same level they would if planted in the ground. Mulch heavily for added protection.

 

Drying winds and temperature fluctuations are as much an issue as low temperatures when it comes to winter survival. Soil heaving can occur when soils freeze and thaw repeatedly, potentially breaking roots or exposing sensitive parts of the plant. Larger containers can help mitigate soil desiccation and temperatures and therefore increase chances for winter survival. You can also simulate this positive effect by grouping containers together. Allow the containers to protect each other by placing larger containers on the outside of the huddle and smaller containers on the inside. Get added protection by placing in an area protected from wind and mulching around and over the tops of the pots.

 

Unheated indoor spaces like garages or sheds are another option. Many perennials require annual cold temperatures and a dormancy period, so this space should ideally stay around 30º - 40ºF, warm enough to protect from injury and cold enough for vernalization. Don’t forget to check on plants stored indoors periodically and water when dry.

 

For all of these options, continue to water plants until soil freezes, and water throughout the winter when temperatures are above 40ºF. It’s important to keep an eye on your containers as temperatures begin to warm and stabilize in the spring. You don’t want to expose plants too quickly to environmental conditions. On the other hand, if protection remains in place too long, plants could start their spring growth prematurely. For those stored indoors, begin to bring outside when night time temperatures are around freezing. Late cold snaps may require bringing the pots back in temporarily, but it’s a small price to pay if they’ve made it that far. For pots huddled together in a protected outdoor location, begin to remove mulch gradually over a number of weeks as the weather warms. For pots sunk in the ground, remove them at the early signs of new growth to avoid their roots growing into the surrounding soil.

Winter Time Considerations for Pollinators and Wildlife

By Sherie Shaffer, Horticulture Agent, CSU Extension-Pueblo County

Warm weather and flower blooms have gone away, but pollinators and wildlife still look to our yards and gardens for survival! Whether it’s shelter or food, we can help buzzing bees and feathered friends by making careful considerations in our landscapes this winter.

First of all, where do these creatures go during the winter? Some butterflies, most notably monarchs, are known for migrating to warmer climates during the winter. However, there are plenty of pollinators and other wildlife that will spend winter in Colorado. Most of our native bee species (which are very important pollinators of native flowers!) don’t survive as the adults we are used to seeing, but as eggs in a nest that their mother has prepared for them. Once the weather starts to warm they will complete their growth into an adult bee and emerge right in time to pollinate flowers. Many birds will migrate south for the winter, but there are many species that will brave the long Colorado winter, even in the mountains. These birds use strategies such as molting, diet changes, torpor (a type of temporary hibernation) and even cuddling up together to share body heat.

Ground nesting bee- Xerces Society

So what can you do to help pollinators and wildlife during the winter? It turns out there are a lot of very simple things you can do at home that will make a big difference!

I feel like I am a bit of broken record on this one, but don’t rake up your leaves! Bumblebee queens, larva of butterflies and moths, and even beneficial insects like lady bugs will overwinter in a leaf pile and be ready to emerge into your landscape in spring.

Lady bug on fall leaves- 123rf

Try to avoid disturbing possible nesting sites as much as possible. Many of our native bees nest either in bare soil or in hollow stems of plants. Making sure you leave the bare soil undisturbed as long as possible, and waiting to cut back plants until spring will ensure that nests are able to survive until spring.

Continue to put out food for the birds. Black oil sunflower seeds are a preferred food for many wild birds. Some other birds are particularly attracted to suet. This article from Gilpin County Extension gives a lot more great tips on feeding birds. Also, next spring consider planting a shrub with berries like a golden currant or three leaf sumac that will help keep the birds fed next winter.

Birds feeding- Boulder Home and Garden Magazine

Winter is almost here, time to relax indoors and dream of spring blooms to come, but the pollinators are still out there, so give them a boost where you can!