Thursday, November 13, 2014

Roses Frozen in Time

Pictures by Linda Langelo - This is a shrub rose with it's blossoms and stems frozen. 

After Monday night's temperatures plummeting into artic cold temperatures, these rose blossoms are now frozen in place.   Only a week or so ago the weather was in the 60's and 70's.  This shrub rose had no time to acclimate to the fast change in the weather. 

Crevice Gardens

Crevice garden in Denver Botanic Gardens, picture by Linda Langelo

The next time you are driving down the highway and through mountain range take a look at the sides of the mountain that butt up against the shoulders of the road. You will find Mother Nature's crevice gardens. For years, we have duplicated crevice gardens in alpine troughs. It has been a way of taking and enjoying up close, small rock garden plants that we treasure and want as part of our landscape.

Now the alpine plants have broken out of their troughs and truly joined our landscapes as crevice gardens. In a crevice garden, you can grow a wide variety of alpines. To place a crevice garden put it in an open area of your landscape not shaded or competing with evergreens or other deciduous plants or trees. Chose stone that is appropriate for your location and landscape which creates a natural blend and not something that screams, "I stick out like a sore thumb."

For a photo detail of planting a crevice garden go to the following website:

Step-by-step pictures are worth more than attempting each step in detailed words. Zdenek Zvolanek from the Czech Republic spent two months creating this crevice garden. In fact, the Czech Republic is the origin of crevice gardens. It is their style of gardening.

Thursday, October 30, 2014

A disease of peach trees: Coryneum Blight

Photo of Reliance Peach by Julie Elliot
Shot hole disease or Coryneum blight will occur on twigs and buds when spring weather is wet.  This disease can occur on peach, nectarine and apricot trees.  This disease can reoccur in these fruit trees, especially if the fruit trees have a history with the disease. 

Watch for small, purplish black spots which first appear on the twigs and can be concentric.  These spots will expand and their centers will be brown with small tiny dark brown spore-forming structures at the center.  These spore-forming structures are called sporodochia.  If you have a hand lens, they can be seen best with a hand lens. 

Besides the twigs, the spots on the leaves can be very similar in nature.  They are small spots starting out as purple and then developing a tan center which will fall out.  Hence the name “shot hole” disease.  Sometimes, the spots may be surrounded by a light green or yellow margin.

It is important to note that this disease can winter over on twigs and buds.  The lesions can continue to spread even at temperatures of 45 F even though the optimal temperatures are ranging from 70 F to 80 F.  If there are periods of prolonged wetness in the fall and continuing to mid-winter, you need to be proactive and use a preventative spray.  According to Colorado State University Extension, specialist Harold Larsen recommends fungicides such as Bravo containing chlorothalonil or copper-containing products such as Bordeaux mixture, Kocide or Fixed Copper can be used as a preventative.  Spraying a preventative, means just that.  What is not already affected will be protected.  A word of warning, copper-containing products should only be used when the leaves are off the trees and during fall is the best time.  Follow the label for usage.  The label is the law.

For those who have sprinkler systems where the water may come in contact with the trunk or lower limbs, this encourages the disease.  The lower limbs of the tree will be where the moisture from a rain dries out last.  This is an area where there can be the most infection from the disease.  It is equally important to rake any fallen infected leaves or twigs so that irrigation or rain does not allow the spores to be spread back on the tree.  The spores can be carried back to the tree by wind during a rain storm. 

For more information on Coryneum blight, you can access CSU Fact Sheet number 2.914 on-line or visit your local Extension Service Office.


Tuesday, August 5, 2014

High And Dry Garden

This garden is located in the Washington County Fairgrounds in Akron, Colorado along the walking trail.   The purpose of this garden is to demonstrate to the public that there are plants that can live, once established with supplemental water from seasonal precipitation.
Some of the plants in the garden are as follows:
Utah Serviceberry                     Amelanchier utahensis
Blanket Flower                         Gaillardia aristata
Four O'clock                             Mirabilis multiflora
Sulphur-flower Buckwheat       Eriogonum umbellatum
Prairie Jewel Penstemon           Penstemon grandiflorus
Pawnee Buttes Sand Cherry     Prunus besseyi
Fringed Sage                             Artemisia frigida
Small-leaf pussytoes                 Antennaria parvifolia

The plant in the forefront is the Four O'clock.  See picture below:

This plant has gone through some of the most driest seasons when we have had less than 7 inches of rainfall.  The plant itself is about 2 to 3 feet tall and covered with flowers.  Besides this plant the Fringed Sage does well on less precipitation.   The Sulphur-flower Buckwheat also does extremely well even though it needs 8 to 18 inches of rainfall a season.  During the hot and dry seasons, Buckwheat prevailed though it wasn't prevalent. 

It is great to have a selection of various plants that do not regular watering such as every week or three times a week.  When we talk about plants needing moderate water, we mean their normal amount of yearly precipitation to sustain themselves.   A lot goes into watering when you factor in the temperature, wind, humidity, soil type, mulch and plant's exposure. 

Tuesday, July 8, 2014

Large-flowered Beardtongue

                                                    Photo by Linda Langelo

An easy to grow perennial is Penstemon grandiflora.  With well-drained soil which has low-fertility, this perennial will do well.  It tolerates drought conditions.  It requires full-sun meaning at least six hours, but at best eight hours.  They flower from May through June.  They produce tiny seeds that will spread these plants around in your garden.

Monday, June 2, 2014

Prickly Rose Gall

Picture taken by Judy Wilson, Support Staff

These galls found on wild roses are "temporary homes" for the Cynipid wasps, Diploplepis bicolor.
These wasps are usually found in galls on oak trees.  For control of these wasps there are no effective sprays at this time.  The galls do not cause any serious harm to the roses.  Prune them out to remove them, if they are not totally covering the rose. The wasps can use daisies and other woody perennials besides roses and oak trees. 

Wednesday, February 19, 2014

Tips for Selecting a Healthy Tree

For balled and burlapped trees:
  • Do not purchase a tree with circling roots at the trunk.
  • Pick a tree with a firm ball of soil.
  • The size of the root ball should be adequate for the size of the tree.
For containerized trees:
  • Do not purchase a tree with circling roots at the trunk.
  • If there are pruned roots in the pot, they should be no wider than a finger.
For bare root seedlings:
  • Roots should be fibrous and moist
  • Deciduous seedlings will have roots almost equal to the length of the stem.
All newly purchased trees need to have the following:

  • A healthy central leader.
  • Have wide-angle crotches for strength.
  • Free of disease and pests.
  • Branches well distributed around the trunk.
  • Do not purchase a wilted tree specimen.
  • Do not purchase a tree with open wounds or mechanical injury anywhere on the bark or main trunk. 
Ask the business selling the trees about the history of the tree.  Questions such as where did the tree originate?  How often do you water the trees? 

The picture below shows some of the worst mistakes someone can make when attempting to give your new tree a good start.  The burlap, wire cage and twine are restricting the root system from becoming established in its new home in the soil.  The burlap and wire cage can be cut back by one third and the twine cut once the ball is in place and pulled out.  In the west, especially during periods/seasons of extreme drought the burlap will not rot.  The wire cage and the twine take hundreds of years to disintegrate.
                                          Picture taken by Linda Langelo

Wednesday, February 5, 2014

Sowing Seed for Spring Transplants

Once you have decided on what you will grow in the garden then you need to start planning on when to start sowing your seed.  Research the average frost dates in your area and start planning the average weeks you will need to grow transplants of the crops you want in time for their appropriate outdoor temperatures.

To get the highest percentage of seed to germinate, here is a list of what crops do the best at an optimal temperature.

Crops that germinate the best at 70 degrees Fahrenheit are as follows:
  • New Zealand Spinach
  • Leeks
  • Celery
  • Celeriac
  • Salsify
Crops that germinate the best at 75 degrees Fahrenheit are as follows:
  • Asparagus
  • Lettuce
  • Onion
  • Parsley
  • Pea
Crops that germinate the best at 80 degrees Fahrenheit are as follows:
  • Beans including Snap Beans
  • Brussel Sprouts, Cabbage including Chinese Cabbage and Cauliflower
  • Carrots
  • Chicory
  • Endive
  • Kale
  • kohlrabi
  • rutabaga 
Crops that germinate the best at 85 degrees Fahrenheit are as follows:
  • Lima Beans
  • Beets
  • Broccoli
  • Eggplant
  • Pepper
  • Radish
  • Swiss Chard
  • Tomatoes
  • Turnips
Crops that germinate the best at 90 degrees Fahrenheit are as follows:
  • Muskmelons
Crops that germinate the best at 95 degrees Fahrenheit are as follows:
  • Cucumbers
  • Okra
  • Pumpkin
  • Squash
  • Sweet Corn
  • Watermelon
With the exception of sweet corn and okra, all the other crops under the 95 Fahrenheit germination temperature do better with a direct sowing out in the garden.

Once the seeds start emerging from the soilless media remove the plastic cover keeping the moisture level high for germination.  If you don't remove the plastic cover (or whatever you use to help keep the moisture in the media) the moisture can cause fungal diseases. 

As you seedlings are growing you need to gradually harden them off or acclimate them to outdoor conditions such as full sunlight and the appropriate temperatures. 


Consider the following factors before planting your windbreak:

  • Height of your windbreak reduces wind speed.
  • Density of your windbreak can reduce the wind speed up to 70% & minimum rows for a windbreak are three.
  • The width of the windbreak gives the windbreak the best density.
  • The a narrow windbreak with great height can equal the density of a wide windbreak unless there is a gap from a dead tree.
  •  Shape of the windbreak could be vertical or stair-step pattern.
If you decide on a vertical windbreak pattern place the tallest trees on the upwind side giving a modest increase in the area protected.

If you decide on a stair-step windbreak pattern with shorter trees on the upwind side and tallest trees on the downwind side provides better efficiency in lifting winds which alleviates less swirling and dumping of wind in the protected area.

What is considered the protected area? Take the height of the tallest tree and measure an area 10 times the height of that tree.  That is the area protected on the downward side of the windbreak.

Here is a great list of information from an article called "Growing Multipurpose Trees on Small Farms." Bangkok, Thailand from a Forestry/Fuelwood Research and Development Project 1992.  Winrock International.  This list seems applicable to the practical side of tree selection:

  1. trees that tolerate harsh environments
  2. have a bushy, deep crown but that still allows some wind protection
  3. keep lower limbs for a long time
  4. have strong roots
  5. grow quickly --this is opposite the next point.  Trees that grow quickly are often short-lived and weak wooded.
  6. live long 
  7. tolerate pests and diseases
  8. not harbour pests that affect nearby crops
  9. not have roots that compete excessively with nearby crops for water and nutrients
I will add trees that are in our native range tolerate the harsh extreme weather conditions than non-natives.  Select natives without creating a monoculture.

Windbreaks do more than just reduce wind speed.  They retain water and gives soil protection.  They can increase crop yields which vary from crop to crop.   They provide shelter for livestock and create a habitat for wildlife.

What trees are recommended in northeast Colorado for windbreaks?

Here are a few recommendations:  Upright Junipers, Eastern Red Cedar, Pinon, Bristlecone, Hackberry, Bur Oak, English Oak, Tatarian Maple, Sumac, Hawthorns and Canyon Maples.    Ponderosa, Colorado Blue Spruce and Austrian Pines are also on the list for tallest evergreens.  However, these three have had the most problems tolerating our extreme drought conditions and are the first effected.  

Monday, January 27, 2014

A 2014 Introduction: 'Windbreaker' Big Sacaton

This is a wonderful grass for its upright, sturdy habit.  At a height of eight feet high and six feet wide, it is a foot taller and wider than the original Sporobolus wrightii.

This windbreaker can be used as a living fence.  It is however, a herbaceous perennial.  The Plant Select Program tested this plant.  It is now listed as a Plant Select Plant because of its ability to adapt to the extreme conditions in Colorado.

The Los Lunas Plant Materials Center in New Mexico originally bred this plant to be a wind barrier according to Megan Shinn of Horticulture Magazine. 

The best part of all is Sporobolus can be grown in garden loam, clay or sandy soil.  It has a watering range from moderate to very dry. 

Sporobolus and plants like this are also great sound and dust barriers.  When the wind blows in Colorado, the dust comes with it. 

Make room for Sporobolus wrightii in your garden.  You will find that it does not need a lot of care.