Thursday, January 23, 2020

Late Winter Pruning Primer

By: Sherie Caffey, CSU Extension-Pueblo County Horticulture Agent

With the holidays behind us, spring is right around the corner. It might seem too soon to start thinking about the outdoors, but it is actually the perfect time to start thinking about pruning your trees and shrubs. Timing is key when it comes to pruning. You also need to consider what you are pruning and what your goals are. 
Late winter is a great time to prune
Any dead, diseased, or damaged tissue on a tree can be removed any time of year. If you are doing very light pruning (less than 10% of the foliage) of live wood, that can also be done at any time of the year. Late winter is considered the routine time for pruning mature trees, before the buds start to swell. Some trees like Elms, Hackberry, Maples, and Mulberries may “bleed” when pruned in late winter. This a cosmetic concern, but if you prefer to wait to prune these species, you can prune them midsummer, after the spring growth flush.
Maples and other trees may "bleed" when pruned in winter
Young shade trees require very little pruning if any, but the training a tree receives when it is young will determine its structure for life. Late winter is the perfect time to do some structural training of a young tree. CSU Extension has a multi-page document that describes in detail how to properly train a young tree, it can be found here:
Spring flowering shrubs such as forsythia, viburnum, lilac, and honeysuckle bloom on the twigs that grew the previous summer. The flower buds develop starting in midsummer and go through the fall to make buds for the following spring. If you were to prune these shrubs in the in the fall or now, you would be removing the wood with next year’s buds, which would prevent flowering. To thin these shrubs, prune right after they bloom. It is also recommended to deadhead spent flowers so the plant can focus energy on foliage and new buds rather than making seed pods.
Prune lilacs after they bloom
Summer flowering shrubs like butterfly bush, blue mist spirea, and rose of Sharon bloom on wood that grew earlier in the same growing season. These types of shrubs set buds in mid to late spring, and then bloom in the summer. You can prune summer flowering shrubs now into early spring before growth begins. Removing older wood will allow better sunlight penetration, and will encourage flowering throughout the shrub, rather than just on the top where there is a lot of sunlight.
            Pruning large, mature shade trees is often a task that can become unsafe for most home gardeners. Hiring a professional to handle these large pruning jobs is the safest approach. Look for an arborist that is certified by the International Society of Arboriculture (ISA). You can find a list of ISA certified arborists here:

Monday, January 20, 2020

Using Dogs to Sniff Out the Bad Guys

Posted by: Alison O'Connor, Larimer County Extension

I wrote a previous post about our U.S. Customs and Border Patrol dogs, who are stationed at airports to sniff out contraband that enters from other countries. They are amazing and impressive...and of course, mostly beagles. Yay beagles!

A Master Gardener recently sent me an article about dogs that are employed to sniff out a devastating citrus disease that is threatening Florida's industry. The disease, Huanglongbing, abbreviated to HLB (thank goodness!) is a bacterium that prevents citrus fruit from ripening. It's also known as citrus greening. The bacteria is vectored by a psyllid, a very small insect related to aphids and mealy bugs.
Psyllids on citrus leaves (photo courtesy of
HLB has been confirmed in the United States in Florida, Louisiana, South Carolina, Georgia; and in Cuba, Belize, and the Eastern Yucatan of Mexico. Since its confirmation in 2005, agriculture authorities estimate that it's caused a 75% decline in Florida's $9 billion industry. Sadly, over 5,000 fruit growers have lost their businesses.
Symptoms of citrus greening (photo courtesy of USDA California)
The leaves of HLB-infected trees are blotchy, and the fruit is smaller in size, lopsided, poorly colored, and worst of all...very bitter. In short, the citrus fruit is of poor quality and no value. The worst part is there's no cure for the disease and it can move rapidly throughout orchards, since psyllids are mobile.

Back to the dogs! You've likely read that dogs have been used for sniffing out cancer, bed bugs, and even emerald ash borer (!!!!!!). In the case of sniffing out threats to our agriculture industry, the USDA has looked at using dogs to detect HLB for over 15 years. They've found our canine companions have a 99% accuracy in identifying the disease. Ninety-nine percent! And the dogs are super fast at their job. They can quickly detect HLB in just a couple seconds, quickly sniffing each tree within the row. The reward for a find? A favorite chew toy.

Jerry Bishop, a dog trainer and handler with Florida-based F1-K9, scouts a Ventura County, Calif., lemon grove for HLB-causing bacteria with Bello, a Springer spaniel. (Courtesy Farm Bureau of Ventura County)

As soon as the dog detects an infested tree (they sit by the culprit), the tree is marked and slated for removal. Dogs are much more accurate and quicker than visual inspections and lab analyses. Compared to dogs, the lab tests, using PCR, only had a 25% accuracy rate. Dogs rule.

Head's up to my two beagles, Maple and Hazel, you could be employed any day! Get your resumes up-to-date. And try to sell yourselves as experts in something other than sleeping.
Maple and Hazel doing what they do best.

Thursday, January 16, 2020

Plant Blindness, It's Real!

Posted by: Deryn Davidson, Boulder County Extension Agent

Did you know that a large percentage of our population is afflicted with something known as Plant Blindess? It’s true! By definition these poor people have “the inability to see or notice the plants in one’s own environment” which leads to "the inability to recognize the importance of plants in the biosphere and in human affairs.” Sad. It seems that most people favor animals over plants. Sure animals might seem more charismatic and dynamic, but come on people!! We would be nothing without plants!!

All joking aside, plant blindness actually has some pretty big implications. The term was coined in 1998 by botanists James Wandersee of Louisiana State University and Elisabeth Schussler of the Ruth Patrick Science Education Center and it’s a pretty fascinating topic. The average person truly just doesn’t process that there are plants in their view. Because plants grow close to one another, are a similar color and don’t move (much), humans tend to lump them together as “non-threatening things” and filter them out of the many, many other bits of visual data the eyes receive.

"There is a kaleidoscopic array of visual information bombarding our retinas every waking second, and plants are so easy to ignore unless they are in bloom," Wandersee says. "Plant blindness is the human default condition."
The issue that arises is that if people don’t pay attention to plants, they won’t place much importance on them and the role they play in our daily lives. They are, of course, not only food, they are medicine, they are fiber, they are fuel, they are beauty, and on and on.

So what can we do about this?? Be plant advocates!! I have no doubt that many of the people that read this blog are already in that camp. Anytime there is an opportunity to tell our family, friends, neighbors and what the heck, complete strangers about the wonders of plants, we should seize that moment! Capture their imagination with your stories of your favorite plants and gardening moments. I would think that exposing younger generations to plants is key. I’m realizing that my two year old has TONS of books about animals, but very few about plants! Okay, he does have “Botany for Babies” but that’s pretty nerdy. Maybe if there were board books with photos of different plants he would be able to identify petunias and peonies just as quickly as he identifies gorillas and cheetahs! Wandersee recommends having a plant mentor in your life, or perhaps you can be the mentor! I am encouraged by the huge uptick in interest around houseplants (if you didn’t know, houseplants are SUPER in right now) and what that will do to combat plant blindness. The work of volunteer programs like State Master Gardeners is doing a lot to help educate the public about the importance of plants and various plant societies and botanic gardens too. 

So if you’ve been putting a lot of time and effort into your garden and are wondering why people aren’t knocking down your door to compliment you, it’s probably because they just don’t see it. Keep up the good work and little by little we'll help combat plant blindness!

Monday, January 13, 2020

A long history of fruit production in Colorado

Colorado has a long history of fruit production. The people who first started growing fruit in
Colorado were a hardy, determined lot who had to learn through trial and error. We owe a great
deal of thanks for fruit production in Colorado to these early pioneers.
It was once a very common saying that “you can’t grow fruit in Colorado”. Fortunately, the
unwavering ground breakers didn’t listen to the naysayers. Their persistence and determination
during the costly experimental stages of fruit production rewarded them. They overcame the
challenge of learning what varieties would grow in Colorado’s climate and how to grow fruit by
means of irrigation and methods of treatments. According to the Boulder Apple Tree Project , Colorado was one of the top apple-growing states in the United States.
Once, there were thousands of acres of orchards in the Denver area and along the Front Range. A
CSU bulletin titled Fruit Interest of the State tells us that by the 1890’s apples were the primary
fruit crops, but plums, pears, peaches and cherries were also grown across the state. It’s exciting
that a number of these historic orchards that were started in 1868 still stand!

On the Western Slope of Colorado, the Grand Valley apple boom occurred about 1895 when
promoters planted thousands of acres, in five, ten, twenty, and forty-acre plots. Western Slope
fruit won prizes throughout all parts of the U.S. for the fruit’s beauty, color, and taste. In 1908
fourteen varieties of Grand Valley apples won sweepstakes at Cornell University. When thirteen
carloads of fruit from Colorado and other Western states were exhibited at the National Apple
Exposition held in Denver in January 1910, Grand Junction won the sweepstakes for the best
carload of apples along with a $1,000 award. Fruita came in second place with $500. In 1913,
Grand Valley apples took first prize in Cleveland, OH. It’s said that Grand Valley fruit won blue
ribbons in all the major cities where it was exhibited.

During the apple boom of 1895, a large number of the newly planted orchards were sold to
eastern buyers, mostly professional people. Unfortunately, these people knew very little, if
anything, about growing fruit, especially in irrigated orchards. As a result, over irrigating and
poor soil drainage led to a build up of salts and over-watered, stressed trees. This of course led to
unhealthy trees and lowered production. Codling moth soon became an overwhelming problem
with neglected orchards of apples and pears everywhere.
The trees were so infested with pests that there was no hope for any solution and before they knew it, the fruit industry was ruined. Colorado late spring frosts and hail on the Front Range effected many growers.  Many of the orchards were eventually converted to more tolerant crops.
Fortunately, fruit production is alive and well today.

It’s so fantastic that people are now looking into the history of these orchards and the trees that
once grew there. Organizations such as The Applecore Project of Western Colorado is advancing fruit tree preservation through the use of mapping
tree varieties, identifying trees, grafting and planting new trees, as well as documenting and
connecting local resources towards preservation. They are rediscovering the stories of the people
who planted and cared for these trees.  The Montezuma Orchard Restoration Project is another great organization helping to preserve the fruit history. For example, did you know there was once a Colorado Orange Apple? This “winter” apple was a mix of sweet and tart flavor with a surprising orange-ish color. Orange Apple Thanks to Jude Schuenemeyer, with the Montezuma Orchard Restoration Project in southwestern Colorado, this apple has been rediscovered. The apple was believed to be extinct.

But one day Jude says he and his wife were in an orchard in Canyon City when “lo and behold,
on the ground underneath the tree in the duff, there were these orange-blushed apples. And then
on the tree, there were some of the apples still hanging.” They say the apples have a fantastic
complex flavor. This wonderful apple almost went extinct because people preferred bright red
apples over this unique variety. Through DNA testing and comparing their find to some archival
wax apple replicas at Colorado State University they’re now about 98% sure that they have
discovered the elusive apple. How great is that!
Thanks to these brave pioneers we are now enjoying the fruits of their labor.

By Linda Corwine McIntosh
Colorado Master Gardener Tri River Area, ISA Certified Arborist, Commercial Pesticide Applicator

Tuesday, January 7, 2020

Is Natural Grass Really Better than Synthetic Turf?
Tony Koski
Extension Turf Specialist

It has been a while since I last wrote (some called it a rant) on this topic. That was in 2016, right here, in making the case for the playing surface in CSU’s new football stadium to be natural grass. Obviously that didn’t happen. And I would still argue that the decision to install synthetic turf in our stadium was a misinformed choice for so many reasons. While the companies that peddle synthetic turf to uninformed athletic directors, school boards, parks directors, coaches, booster clubs, etc. make the case that synthetic is (compared to grass) cheaper to maintain, easier to care for, longer-lasting, more environmentally friendly, and safer – those that do their homework can easily find evidence to the contrary.

As I did acknowledge in that 2016 blog (and still do), there are situations where the use of synthetic turf makes total sense and is clearly a better choice than using grass. But I would argue that, in MANY cases, the choice to install synthetic simply doesn’t make economic sense – at least if that is the most important consideration. When amortized over a 10 or 20 year time period, savvy entities from cities like San Diego to small high schools are refusing to drink the “synthetic is cheaper/easier/safer” Kool-Aid.

More important than economics is the question of player safety and injury rates between the two types of playing surfaces. Early 2000s research on synthetic/natural turf injury rates was rudimentary, and the results were cherry-picked by synthetic turf companies to paint their product as actually being safer than grass for athletes. In recent years, much more in-depth research has been conducted. The most convincing, long-term science has been done by the National Football League, the NCAA, and international football and rugby entities – using injury data collected over many years of play on both types of field surfaces.

Injury rates of NCAA football players on synthetic vs. natural
grass playing surfaces (visual courtesy of Dr. Casey Reynolds
and Turfgrass Producers International)
Without getting too detailed (you can read more, citations below), the NCAA study (examining injury data covering 9 years) found PCL (posterior cruciate ligament) injury rates to be about 200% greater for football played on synthetic turf compared to natural grass.

Non-contact injury rate for NFL players on synthetic vs. natural
grass playing surfaces (visual courtesy of Dr. Casey Reynolds
and Turfgrass Producers International)
The NFL study, examining all lower body injuries occurring between 2012 and 2015 (all 32 NFL teams), found an overall 16% higher injury rate when playing on synthetic turf. Some of the most surprising numbers were found regarding non-contact injuries. Overall non-contact injury rates were 27% higher for synthetic turf – including a 103% higher rate of ankle injuries that resulted in more than 8 days of time lost being able to play or practice.

Increased interest in and sophistication of playing surface research is showing that type of sport (soccer vs. football vs. rugby), player age and size, gender, shoe cleat type, competition level, practice vs. game contact, player position, and even whether a player is right- or left-footed all play a role in the occurrence of injuries when comparing synthetic and natural grass surfaces.

The preponderance of research-based evidence suggests that well-maintained natural grass is likely safer for athletes than synthetic surfaces. When the economics (amortized over the realistic life cycle of fields) are taken into account, natural grass is also a winner. If you are ever in a position to influence a natural grass vs. synthetic turf decision, please dig deep for answers – and resist drinking the synthetic turf Kool-Aid.

For more details on the NFL and NCAA studies, see this excellent article by Dr. Casey Reynolds, the Executive Director of Turfgrass Producers International.

Loughran, G., Vulpis, C., Murphy, J., Weiner, D., Svoboda, S., Hinton, R., and Milzman, D. 2019. Incidence of knee injuries on artificial turf versus natural grass in national collegiate athletic association American football: 2004-2005 through 2013-2014 seasons. The American Journal of Sports Medicine. 47:1294–1301.

Mack, C., Hershman, E., Anderson, R., Coughlin, M., McNitt, A., Sendor, R., and Kent, R. 2019. Higher rates of lower extremity injury on synthetic turf compared with natural turf among National Football League athletes: epidemiologic confirmation of a biomechanical hypothesis. The American Journal of Sports Medicine. 47:189-196.

Thursday, January 2, 2020

Pollinator Resolutions for 2020

Posted by: Abi Saeed (Agriculture, Horticulture & Natural Resources: Garfield County)

Hap-BEE New Year!

Pollinator conservation can seem like a daunting task at first, but everyone can take small steps to create a positive impact for these beneficial insects, birds, and mammals. By taking intentional actions towards safeguarding pollinators, in addition to continued learning- we can create a more inviting and pollinator friendly landscape. We hope you will join us in our pollinator conservation and outreach efforts for 2020.

Pick and choose from the following list of Pollinator Resolutions:

·        Know your pollinators
o   Whether you are an avid gardener, a biologist, or someone who simply enjoys plants, there is always more to learn when it comes to pollinators. Do you know the pollinators that can be found in your own backyard? Can you differentiate between a bee and a wasp? Do you know the difference between a flower visitor and a pollinator?
o   Learn more about our pollinators here:

·        Plant the right kind of flowers
o   Flowers can vary widely in terms of habitat suitability, bloom time and duration, nectar/pollen availability, and accessibility by pollinators.  Knowing about the types of flowers favored by pollinators can help in creating more efficient pollinator food sources that are suited to the needs and preferences of your local pollinators.
o   Learn more about plants for pollinators here:

·        Create some nesting habitat
o   Nesting habitat can look different, depending on the type of pollinator. There are several resources available to point you in the right direction whether you want to create nesting sites for ground nesting bees, cavity nesting bees, birds, or bats.
o   Learn more about pollinator habitat here:

·        Adopt pollinator friendly pest management practices
o   Adopt Integrated Pest Management (IPM) and Integrated Weed Management (IWM) strategies.
o   Always read and follow label directions on any pesticides (including herbicides).
o   Never spray a plant that is currently in bloom (or about to bloom).
o   Learn more about pollinators and pesticides here:

·        Tell your friends and family
o   Spread the word about pollinator conservation, and educate your family, friends, and neighbors! The more people who adopt pollinator conservation practices, the better it is for the overall health and well-being of our pollinators.

·        Continue to learn!
o   Keep up with the latest science-based information on pollinators and adapt your conservation strategies accordingly!

Colorado State University Extension has assembled a dedicated Pollinator Habitat and Awareness Work Team that will be focused on creating more pollinator conservation resources for Coloradans. Together, with CSU and local counties/regions, we aim to offer more pollinator focused education throughout the state of Colorado. Stay tuned for the first Thursday of each month for a pollinator focused blog post, and search #coloradopollinators for more information and updates.  

Monday, December 30, 2019

2019 "Top Performer" Perennials Announced from CSU Flower Trials

Posted by Jim Klett, Professor, CSU Department of Horticulture and Landscape Architecture

Our three year (2 winter) herbaceous perennial trials at Colorado State University continues to grow each year with 115 new entries for a total for 270 entries. Plants are evaluated for plant vigor, uniformity, floriferousness and tolerance to environmental and biotic stresses. The following six perennials have been awarded the 2019 “Top Performer” perennial designation after performing superiorly for three growing seasons and two winters in our Fort Collins, Colorado trials.

A complete report on the perennials in the trial can be viewed at under Perennial Trials menu.

Millenium Ornamental Onion from Eason Horticulture Resources and Stonehouse Nursery
(Allium hybrid 'ALLMIG1')
This was a definite “show stopper” plant that was described as having an “insane” amount of blooms.  Flowers were a nice shade of pink and were a favorite of many bees and butterflies.  The flowers combined well with a nice compact plant with clean foliage and very uniform growth habit.  Blooming lasted a long time and flowers did not lodge even with overhead irrigation.  It has been reported to grow well even at 8,000’ in the mountains.  Removal of spent blooms can result in some repeat blooming or can be left for winter interest.  Judges were in unanimous agreement to designate it as a winner. 

Kahorie® Scarlet Border Pinks from Dummen Orange

(Dianthus x hybrida Kahorie® 'Scarlet')
Very showy in the spring with a very vibrant color and attractive plants.  Flower color was not a true scarlet but a beautiful shade of hot rose or cherry.  Plants had superior winter hardiness that was consistent over three years and did not die out in the center as did many other Dianthus.  Plants were attractive even when not in bloom with a nice tidy, compact growth habit.

SUMMERIFIC® Cherry Choco Latte Rose Mallow from Walters Gardens, Inc.
(Hibiscus x hybrida 'Cherry Choco Latte'PPAF)
Large, two tone blooms were captivating with a striking combination of pink and white.  It makes a great choice for providing color late in the season.  Plants were relatively low maintenance as the old blooms were self-cleaning.  Foliage had shades of dark red that was maintained throughout the season.   Plants also had a nice growth habit that did not lodge and the mid-size height made a good balance with the flower size.

Lami Dark Purple Spotted Deadnettle from Danziger
(Lamium maculatum 'Dark Purple')
Dark purple flowers combined with dark green foliage and a very uniform growth habit to make a very impressive groundcover.  This versatile plant did not burn in the sun and did well in the shade.   It has also been reported to look great even at 8,000 feet elevation.  Plants have superior vigor and provide a long period of bloom. 

Bandwidth Maiden Grass from Darwin Perennials
(Miscanthus sinensis 'NCMS2B'PP29460)
This is a good selection for today’s smaller gardens and landscapes as the plant maintains a nice uniform growth habit that is only 3-4’ in height.  Plants did not bloom but foliage is very attractive with yellow stripes running across the blade.  The variegated foliage did not revert and was impressive all three seasons.  Flowers are not needed for interest as the yellow and green contrast in the leaves is very showy.

GRANITA® Orange Ice Plant from Plant Select®
(Delosperma ‘PJS02S’)
Bright, iridescent orange flowers blanket the plant creating an impressive show of flower power.  Large flowers bloom over a long period.  Plants make a very attractive ground cover as the beautiful green foliage forms a nice dense mat that tightly hugs the ground.  Vigor is excellent and makes a good spreader.  Cold hardy and well suited for this area.