Noxious Weed Profiles II
We are continuing to profile noxious weeds in order that we all get to know them. Although not the most fun aspect of gardening, it is important that we help to control their spread so as to avoid impacting our native plant and animal populations, and in some cases, helping to reduce the spread of weeds into our own gardens. An added benefit of learning to recognize weeds is that any plant that appears in our garden that we do not recognize to be a weed, may be left to grow. Wonderful wildflowers and other desirables can thus windfall their way into our gardens.[Read More]
When to Prune Trees
I have been an arborist for 35 years and spent a lot of my life studying trees and so I have these comments on When to Prune Trees:
- Yes, wounds close more quickly when pruned in spring
- Yes, for certain pest problems like Dutch Elm disease, it is important not to prune when the beetles are flying and best not to prune fireblight in the early spring.
- And trees without leaves do have a clearer view of the branching, but climbing into the branches gives a far better view and pruning with the leaves on helps determine thinning density as well as judging weight on a branch.
- Alex Shigo, often called the Father of Modern Arboriculture, wrote that pruning can be done anytime unless a tree is stressed, in which case it is better not to prune when a tree is putting on leaves or dropping leaves.
- Summer is a good time to prune fruit and other trees when you are trying make or keep them smaller.
- Fall is the best time to prune for fireblight, after the leaves have started turning color and before the leaves fall off. This is the time when you won’t spread the fireblight on your tools, so you don’t have to disinfect after every cut.
- Cytospera canker disease should be pruned out in dry weather, which usually is not spring.
- The most important factor is not the timing; it is the accuracy of making a pruning cut that neither cuts off the branch collar, nor leaves a stub. Then wounds will close most quickly.
- I asked Dr. Shigo if it is harmful to prune Maple and Birch in early spring when they bleed. He told me it is not harmful. And it seems to me that it doesn’t bleed for more than a few days.
Plants in the Home Greenhouse
The opportunity of winter sun in Colorado for heat and light to grow plants in a greenhouse
- cold and sunny
- short season
- energy from coal and petroleum are expensive and atmosphere-polluting
- greenhouse captures free energy
- greenhouse is a tool to produce food and
- is a cheerful winter room
- protects plants from deer, raccoons, hail and grasshoppers.8) efficient use of water
The Other Three Vines at the Teahouse
In the last issue I discussed three vines recommended by Jim Knopf for serving the special needs of the Boulder-Dushanbe Teahouse arbors. These vines were Clematis tangutica, Bokaravine Fleeceflower, and Riverbank Grape. Because the legs supporting the arbors are 12’-15’ tall, only the most cold-hardy and vigorous vines could be used.[Read More]
The Native Artemisias
There are several native artemisias that are naturally well-adapted to our soils and climate, drought-tolerant, and useful in our landscapes. These silver-leafed shrubs make great contrasts with green foliage and great foils for flowers of any color. They are now classified under three genuses: Seriphidium, Oligosporas and Artemisia.[Read More]
To Plant to Fertilize
(Just this PDF – should we turn it into a regular page?)
Xeriscaping with Natives
What group of plants has the longest proven record of success in Colorado for enduring the radical ups and downs of our weather, including droughts? Our native plants, of course. And if we give them similar conditions to what they have in nature, they will succeed with little care. Here are a few of my favorite native plants that have thrived in my xeriscape garden for the past 10-15 years.
Liatris punctata, the Dotted Gayfeather stores its energy in a thick taproot that helps it produce flowers even after a dry summer. The tufts of rough, narrow leaves are little-noticed until they shoot up their thin flower spikes to 10”-16”, and burst into bloom with lavender-violet “feathers” in August or September. They are especially dramatic in groups of four to ten plants, and they can continue to bloom for a month or more. Liatris punctata is native to the foothills and plains of Boulder County, and unlike cultivated varieties, needs no supplemental water once established.[Read More]