CO-Horts

CO-Horts

Monday, April 24, 2017

Dwarf Mistletoe in Ponderosa Pines posted by Mark J. Platten



I’ve received numerous calls regarding southwest dwarf mistletoe (Arceuthobium vaginatum subsp. cryptopodum) in ponderosa pines over the years.  They are leafless, parasitic plants that infect several species of conifers, producing root-like structures that grow in the living tissue, where they extract both nutrients and water from their host plants.  
The southwest dwarf mistletoe is relatively host-specific and generally doesn’t affect other tree species in our region other than the occasional limber or bristlecone pine. 



Symptoms and Signs
From a distance, coniferous trees infected with dwarf mistletoes may appear to have yellow foliage, reduced foliage, abnormally dense green and distorted foliage known as witches’ brooms, and mortality of the upper portion of the affected tree.
The first symptom of dwarf mistletoe infection is a slight swelling of the bark at the infection site.  The parasite is identifiable when shoots protrude two to three years after infection. 

Damage to Host Trees
The mistletoe and subsequent witches’ brooms extract resources from the tree and may cause mortality.  Death of the host tree occurs slowly in most cases and depends on the severity of infection, vigor, and size of the tree.
Mistletoe severity is established by dividing the crown into equal thirds and rating each.  If there are no visible infections, that third of the crown is rated 0; if 1 to 50 percent of the branches are infected, the rating is 1; and if more than 50 percent of the branches are infected, the rating is 2.
Add the ratings of each third to get a total rating.  Ratings of 3 or less are considered light, 4-5 moderate, and 6 heavy.  Life expectancy is based on tree diameter and severity of infestation.  For diameters of nine inches or less, the range is 7-30 years.  For diameters greater than nine inches, life expectancy is in the range of 10-60 years; with the low number reflective of heavy rating and the high end based on light ratings.



Spread
Their life cycle, from initial seed germination to producing fruiting bodies, is 6-8 years, providing time for management.  The sticky seeds literally explode via hydrostatic pressure at almost 60 miles per hour!  Seeds that adhere to young branches of susceptible trees germinate and the mistletoe rootlet penetrates the bark.  Dwarf mistletoe seeds generally are dispersed in August and early September.  Birds and other animals can occasionally spread the seeds some distance to uninfected trees. 

Management
Although mistletoes cause a gradual decline of plant health, trees may become stressed, attracting mountain pine beetles, Ips beetles, and twig beetles that may kill the tree.  Mistletoe management options include branch pruning, tree removal, and planting resistant tree species.

Branch Pruning and Tree Removal
Pruning witches’ brooms and removing infected trees is the best management measure available to reduce or eliminate dwarf mistletoe infestations in stands of high-value trees.  First, remove severely infected trees (trees rated 5 and 6) or those with only a few live branches.  It is not necessary to completely eradicate the mistletoe, since this may require removal of all trees.  Pruning infected branches and removal of a few heavily infected trees can keep a green forest on the property.
Pruning the lower and the largest witches’ brooms from lightly to moderately infected trees (trees rated 1 to 4) can improve the health and allow these trees to survive for decades.  Examine trees every two or three years, removing any newly infected branches.  Mistletoe shoots die as soon as the tree branch is cut, so no special disposal is needed.  If space allows, create a 50 foot buffer zone between infected trees and healthy trees that may be affected.  Contact a professional forester, the Colorado State Forest Service, or other professionals to obtain help in these decisions.

Hawksworth Six–class method for evaluating dwarf mistletoe infection (Hawksworth 1977)


Plant Resistant Tree Species
Planting resistant or non-host tree species in areas with infected trees will ensure that trees will be in the area even after the infected trees are remove.

Chemical Sprays
Ethephon is a growth-regulating chemical that can be used to remove mistletoe shoots and reduce seed production.  This treatment does not kill the entire mistletoe plant, just the shoot. Re-treatment is necessary until infected trees are removed, mistletoe infections are pruned from the tree, or new non-host trees are planted.

For more information on dwarf mistletoe, please see CSUE Fact Sheet:  http://www.ext.colostate.edu/pubs/garden/02925.html

Monday, April 17, 2017

Atomic Gardening


By Cassey Anderson, Adams County Extension

Photo Credit: http://www.atomicgardening.com/1958/10/01/rebuilding-plants/ 
Listening to a podcast awhile back I learned about a form of gardening I had never heard of before. In the 1950s scientists realized that, in the presence of gamma radiation, plants would mutate.  Interest in crop mutation grew out of a combination of food insecurity as a consequence of World War Two and the discovery of the power of the atom. In the fallout from the atomic bomb in Japan, people noticed that sesame plants near the blast site grew much larger than non-irradiated sesame plants. This sparked an interest in scientists and lay persons alike seeking to see if they could safely replicate these effects.



Gardens, named atomic gardens, were arranged in a radiating pattern with a radioactive source at the center, typically cobalt-60 (ironically these gardens resembled the warning symbol for radioactivity). While the plants nearest the radiation source would often be stunted or die, those further away were likely to exhibit a wide variety of mutations.  The results were highly unpredictable but there were some successes from irradiated seed. This was the period in which radiation was perceived as likely to make things stronger, rather than weaker. Think Spider Man, Godzilla, Atomic plants; they all fit in the same optimistic mentality of the benefits of radiation.
An early Atomic Garden.
Photo courtesy of http://www.gardenhistorygirl.com/2010/12/atomic-gardens.html

A woman in Britain, Muriel Howarth, started the Atomic Gardening Society to encourage homeowners to plant seeds from these irradiated plants. Howarth even published a how-to guide on Atomic Gardening, titled the same. Her goal with her home gardeners, who she called “Atomic Mutation Experimenters”, was to work to help scientists produce food more quickly for more people and progress mutations to promote food security. The seeds from the plants grown in this manner were not radioactive, but did have radiation induced mutations.
Photo courtesy of:  www.atomicgardening.com/resources 

In one of the research gardens in Rhode Island plants placed in the radioactive garden included plants ranging from strawberries to sugar maples. By 1958 government labs around the world had set up atomic research gardens. Muriel Howarth tasked her Atomic Mutation Experimenters with keeping data on the progress of the plants they grew out for scientists. Many seeds did not produce a plant or a satisfactory product, as blasting a plant with radiation receives erratic results.
Current gamma garden at the Institute of Radiation Breeding in Japan.
http://www.atomicgardening.com/2017/01/01/yes-atomic-gardens-still-exist-today/

Home gardeners became discouraged with limited results from their research plants, and even government programs with dedicated personnel produced only limited results. The final program in the US was discontinued in 1979. However, there is still a working “gamma garden” in Japan, the Institute of Radiation Breeding. There is also a collaboration of scientific research focused on nuclear techniques in food and agriculture called the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture to help improve global food security and promote sustainable agriculture development.


There are some survivors in our food supply from this strange period of atomic gardening. You may be familiar with the Rio Red grapefruit, and ‘Todd’s Mitcham’ peppermint for oil production, they are both byproducts of atomic mutation experiments. The Joint FAO/IAEA division lists over 3200 official mutant varieties from 214 different plant species. 

Thursday, April 13, 2017

FireWise Landscaping

FireWise Landscaping

 By Linda Langelo, CSU Horticulture Program Associate, Golden Plains Area
Fire can happen on any landscape, at any time.  Incorporating preparation and prevention can assist with lessening the threat of fire.  
A fire on the plains can be effected by three things:
·        Surface fuels
·        Fine, fast-burning fuels
·        Usually driven by high wind
Photo Credit: Colorado Forest Service, Boyd Lebeda



What can you do when faced with a grass fire that travels quickly?  What preparations do you need to put in place around your home, long before a wild- fire? 

Aside from all of the above information, before fire season, stand back and look at your landscape differently can help prevent disaster to your family’s home.

First, according to the Colorado Forest Service when renovating your landscape around your home, this requires a defensible space.  This space serves as a buffer between your home and the trees, shrubs, perennials, grass and any wildland area that surround your home.  Do you have an evergreen planted up against your home? Does the ground slope away from your home?  What types of are established vegetation on your property?  All are factors to your ability to mitigate fire damage to your home.  CSU Forest Service recommends keeping your defensible space clean of trash and debris.

Second, everyone’s home has weak spots and hardening your home means using construction materials that can help your home withstand flying embers and shore up those weak spots.  Do you have a wood deck that attaches to your home? Are there garden tools with wooden handles or brooms or other highly flammable materials under the deck such as pine needles or leaves?  How often do you clean your gutters of debris? 

Third, have a Family Disaster Plan that has evacuation routes in place in case your family is asked to evacuate, a meeting area outside the fire hazard area and a Disaster Supply Kit.  This kit needs to last for at least 3 days and contain your family’s and pets’ necessary items.  Some of these items might be prescription medicines, cash, water, clothing, food and first aid.

Preparation goes a long way towards the success in a fire disaster or any disaster.  Disasters can put people in a panic mode.  If you have a plan, having a disaster supply kit insures that you may not forget medicine or something equally critical and the plan helps save lives. 

Now that you have an idea of what fuels a fire and what you need to do, you can add fire-resistant plants to your property and still have a beautiful landscape. There is a factsheet listed below which I have referenced in this article.  There are some wonderful native plants such as some of the perennial native forbs(wildflowers):

·        Echinacea purpurea, Purple Coneflower

·        Ratibida columnifera, Prairie Coneflower

·        many different species of Penstemon. 


Beyond these there is a wide list of non-native perennial choices from the FireWise Plant List on the FireWise Plant Materials Factsheet:

·        Ajuga reptans          Bugleweed

·        Lamium spp.            Dead nettle

·        Armeria maritima   Sea thrift

There are a number of shrubs and trees from which to choose from the same factsheet:

·        Prunus cerasifera               Flowering plum

·        Amelanchier alnifolia        Saskatoon alder-leaf serviceberry

·        Shepherdia argentea         Silver buffaloberry

·        Crataegus spp.                    Hawthorn


Here are some CSU links for Fire-Resistant Landscaping and FireWise Plant Materials that you can access for guides also used as references for this article:

CSU Quick Guide Series – Protecting Your Home from Wildfire: Creating Wildfire-Defensible Zones formerly CSU Extension Factsheet 6.302 –link:



CSU Forest Home Fire Safety Factsheet 6.304

CSU Fire-Resistant Landscaping 6.303

CSU Fire Wise Plant Materials 6.305









Monday, April 10, 2017

More Bees Please!

By:  Kelley Rawlsky - CSU Extension, Broomfield



Thinking back to my childhood days of sprinting across grandma’s clover lawn barefoot trying to avoid stepping on and consequently getting stung by bees, I never thought I’d be one to promote increasing their population. If you have ever stepped on a bee, it is quite painful. The stinger of the honey bee is barbed and embeds into the skin, and the stinger and poison sac are left behind. Does the honey bee really die after stinging? Unfortunately, yes.  

After studying horticulture and learning the importance of bees and other pollinators, I am firmly now on their side. Honey bees, in particular, are exceptional pollinators. Many crops, including apples, pears, peaches and melons, are dependent on them. CSU Extension has estimated the value of this pollination, which is provided freely from the local honey bees for our crops here in Colorado, at greater than $20 million annually. This doesn’t even include the several million dollars of honey and beeswax products that are also produced. So, bees are important!


We’ve all heard about the declining bee population. The reasons why this is occurring are varied and numerous, but the good news is we can do our part by planting more pollinator friendly plants in our yards. This will help the bee population by giving them nectar and pollen, but it will also help draw these pollinators to our yard so they can help pollinate our own edible gardens. 

 Attracting more bees to the yard is mostly beneficial, but if you or someone who frequents your yard is allergic to bee stings, then it might be a good idea to take a pause and rethink your approach to including a pollinator garden. Approximately one percent of the population develops hypersensitivity to bee or wasp stings which can then result in difficulty breathing, dizziness, nausea and hives. Symptoms, such as these, may require immediate attention from a physician.


In my own yard, planting a lot of pollinator plants has had some unintended consequences. Our 10 year old labrador retriever likes to snatch up flying, buzzing insects with her mouth. It’s quite obvious that she gets stung most of the time because of the way she shakes her head afterwards with a puzzled look. As many times as I try to explain to her that bees are our friends, she just doesn’t learn.




What to plant? Flowers! Here are some good choices that are water-wise and well adapted to our climate: Agastache rupestris (hummingbird mint), Echinacea purperea (purple coneflowers), Penstemon x. Mexicali, and Perovska atriplicifolia (Russian sage). For a more detailed list, see: Gardening for bees - or not! by Whitney Cranshaw, ColoradoState University



In case you're wondering, not all of the pics included are of honey bees. Maybe there's an entomologist out there who can identify them for us!

Friday, April 7, 2017

Hort Peeve and Pleasure: Fertilizer Spreaders

Posted by: Alison O'Connor, Larimer County Extension

Spring is off to a racing start in the Front Range of Colorado this year. I had a Master Gardener tell me that she keeps a historical diary of when plants bloom and this is the earliest she's ever seen Callery pear and crabapples in full bloom.

With the early spring come lawn questions. To be fair, lawn questions occur most of the year, but generally the most frequent questions start in late April to May when things aren't greening up like they should. But not this year--I started booking Lawnchecks (lawn evaluations) in March.

Lawnchecks are one of my favorite things to do, primarily because there are so many old wives tales surrounding lawn care--such as leaving grass clippings on the lawn leads to thatch (it doesn't), you shouldn't water at night because it causes disease (it doesn't) and every weedy grass is crabgrass (it's not). I find that doing these visits is one of the best ways to dispell myths and get homeowners the correct information.

One thing that's surprised me is how people fertilize their lawn. We see a lot of "hungry" turf out there and when we ask about fertilization, the answers are all over the board. First of all, fertilizer is good for the lawn. The healthier the lawn is, the fewer weeds it will have. Healthy turf also benefits the environment.
Early spring greening of a lawn in Loveland.
Use whatever fertilizer you like. The lawn doesn't care if the nitrogen comes from chicken poop or the Scotts Company. There is no "best" fertilizer, just like there's no "best" car. They all have advantages and disadvantages. But it is very important on how you apply the fertilizer.
Find a fertilizer you like! It's kind of like shampoo...something for all lawn types.
So many clients use the hand fertilizer spreader...on their 3000 square feet of turf. First of all, this leads to a lot of cranking and is also a very inefficient and non-uniform application of fertilizer. The hand-crank fertilizer spreader is best used on very small lawns (<500 square feet). I can understand why it's attractive to consumers--it's compact and easy to use. But to fertilize a typical lawn with one pound of nitrogen per 1000 square feet would mean filling the hopper about 30 times (not an exact number). That's not my idea of easy! So you end up fertilizing less, thus leading to a "hungry" lawn that can't combat weeds and other stressors, like disease and insects. Plus, the fertilizer bags do not list the hand-crank spreader as an option, so it's a wild guess as to what setting to use.
The hand-crank fertilizer spreader. Only useful on very small lawns.
Instead, it is worth it to invest in a push fertilizer spreader. I know that you're only using it a couple times of year and it takes up space. But you can also use the fertilizer spreader to apply seed if you need to overseed. If space is an issue, see if you can borrow one from your neighbor...or the neighborhood hardware store. You can also rent them. The big thing is to make sure the fertilizer you bought has the spreader you're using listed on the bag so you can set the spreader accordingly. Using the correct fertilizer setting will ensure that you apply one pound of nitrogen/1000 square feet.
A push fertilizer spreader. Best for typical lawns.
Push spreaders are two types--drop spreaders and centrifugal ("whirly-bird") spreaders. Drop spreaders drop fertilizer directly below. This means that you walk a lot more to apply fertilizer, but it also means that the fertilizer is staying on the lawn and not spraying to sidewalks or driveways (very important). Centrifugal spreaders can cover larger areas more quickly and do have "edge guards" when you're near a sidewalk or driveway. Just be sure to use them. Fertilizer in our sewers is not a good horticulture practice.

So fertilizer spreaders are a peeve and a pleasure. It's good that you fertilize your lawn...but make sure you do it accurately using the right equipment. After you fertilize, make sure it's watered in well (or time it with precipitation). Happy fertilizing!

Wednesday, April 5, 2017

Vermicomposting

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

This fall, I took a big life step and purchased my first home. Sadly, when the move took place, I had to leave behind many of my plants, and my compost pile. Bummer. Right when I was really starting to feel the void my lost compost pile was creating in my life, one of our Master Gardeners taught a composting class, and turned me on to vermicomposting.

Vermicomposting, more commonly called worm composting, is so easy that even someone completely absorbed by a new “fixer upper” can do it! It takes hardly any space, it’s super cheap to get started, and it is less labor intensive than a traditional compost pile. The worms really do all the work. Here’s what you need to know to give vermicomposting a shot…

The first thing you need is a worm bin. It is incredibly easy to make one out of two plastic storage containers. I like the 3 gallon Rubbermaid Roughneck containers, because the handles prop up the top bin up so that there is space between it and the bottom bin. You will need a drill and a couple different sized drill bits, as well as some screening and glue.
The storage containers I prefer

To begin, drill holes along the bottom and the lower sides of the inner bin (the one the worms will live in). These holes will be for drainage in case your bin becomes too wet. Don’t drill holes in the outer bin, which is used to catch any liquid that leaks out. I used a 1/16 inch bit for the drainage holes. Next, use a larger bit (1/4 inch) and drill air holes near the top of the bin.
Drilling holes in the bottom of the inner bin
Drilling holes on the side of the inner bin
View of inner bin with holes drilled
Drilling the air holes




The larger air holes are big enough for a sly worm to escape out of, so they need to be covered. Use a nontoxic, water proof glue to adhere aluminum insect screening over the holes. The glue will need to dry before moving on. I used large binder clips to hold the screen down while the glue dried. Warning: don’t let the binder clips touch the glue, or they will rip the screening off once you remove them. Yes, I am speaking from experience. You can decorate your worm bin if you are feeling crafty. Our local composting guru made these awesome “Compost Happens” bumper stickers that I used to liven mine up.
Glue for the screen

Use a binder clip to hold the screen on



Next, you will need to get worms. Red Wigglers are the best for worm bin composting, because they adapt easily to new environments, and they reproduce faster than the earthworms in your yard. You can buy them online, or if you are lucky like me, you have friends with worms to spare! You should only need a handful to get started, they will make more as time goes on. One pound of Red Wigglers can break down 3-5 pounds of kitchen scraps a week.

Now that you have your worms, you need to prepare the bedding. I used shredded newspaper. You want to wet your bedding until it is as moist as a wrung out sponge. It is best to moisten the bedding in small layers so that it does not clump up. The worms should be able to crawly freely through the moist, shredded paper.
My worms trying to escape the camera

Once the bedding is properly wetted, you can sprinkle the worms right on top. They will work their way down into the bedding to avoid light. The worms will start to feed on the bedding. It is best to let them get acclimated to their environment for a week or so, then start adding food scraps, slowly at first. You could end up with a smelly bin if you add too many scraps too fast.

When you add scraps, pull back a small amount of bedding on one side and bury them underneath, then cover the scraps back up with the bedding. Do this in a different spot each time, and by the time you get back to the first spot, the worms should have composted most of the scraps.
The moist bedding

As far as what you should add to your bin, it’s pretty much the same as a traditional compost pile. Try and keep your carbon (bedding) to nitrogen (scraps) ratio pretty even. Don’t stress too much about this, composting doesn’t need to be an exact science, remember what our Master Gardener says, “Compost Happens”! Kitchen scraps can include fruits, veggies, coffee grounds, tea bags, and peelings. Avoid meats, fats, and dairy as they are a recipe for a smelly bin.

So once your worms have done their job and you have compost, what do you do with it? The volume will be small, but you can use it just like any other compost. Add a handful to the base of your houseplants or garden plants. You can also mix it into potting soil when repotting. Research has also shown that adding a little to your seed starting mix will give you stronger seedlings.


I hope you are inspired to start a little worm colony of your own. Mine worms have become the office pets, and they get everyone’s lunch scraps. Here are a couple of helpful links with further information: http://lancaster.unl.edu/pest/resources/vermicompost107.shtml, http://www.ext.colostate.edu/sam/vermicompost.pdf.  Happy composting!