Tuesday, July 14, 2009

Xeric Landscapes


People are becoming more and more interested in xeric plants. Xerophyte plants have many different innovative adaptations of their physical to survive an environment of extreme heat and drought. Cactus have spines to help shade the plant and a waxy coating to hold the moisture in the plant. Some plants store water in their stems. Other xerophytes have no leaves and there for no transpiration. Some come out of dormancy for a short period, flower and go to seed and go back into dormancy.


There are many types of plants to choose for the xeric landscape. Calylophus serrulatus is a golden-yellow flowering plant that is very drought tolerant as well being among the native plants. It is readily available in several mail order catalogues.


Plan on planting these xeric plants during the fall when their root system has the opportunity to have a lot more moisture and produce a well-developed root system by next spring and summer. The ability of these xeric plants is to have roots that can grow to several feet in order to have access to subsurface moisture. Some other types of plants are butterfly bush, agaves, ice plants, hesperaloe, hyssop, pussytoes, prickly poppy, fringed sage, red valerian to name a few.


Anyone can go to Plant Select website and search through some seventy selections for xeric plants. Plant Select is a plant program started by Denver Botanic Gardens and Colorado State University in search of plants that were the best selections for our native climate. Among the list some are more xeric than others. There are some listed as annuals and not winter hardy. Pay attention to the zones. For those in northeast Colorado, we are in zone five, but it is better to select plants hardy to zone 4. If we have a slightly colder winter, then the plants are sure to overwinter.


The last and most important point about xeric plants is they need to be well-drained soil. Some of the plants can tolerate a periodic flooding, but if their root systems sit in consistently wet soil the crown of the plant will rot, along with the roots.


Go out and explore and add some xeric plants to your garden today.

Monday, July 13, 2009

European Elm Flea Weevil


Throughout the Golden Plains Area, the European elm flea weevil is a pest that has been in the United States since 1982. Now it is showing up in Siebert, Wray, Paoli and Holyoke, Colorado. This pest attacks Siberian elms and has been doing so in the upper Midwest since 2003. The adults begin chewing holes in the leaves. The feeding usually starts in May and early June. We are still seeing activity from the adults here in July. The females lay eggs in the mid-vein of the leaf. When the larvae hatch, they begin to mine the leaf tip. The mined area enlarges into a blotch. Once the larvae pupate, they emerge from the leaf and in late July or early August.

These weevils can do extensive damage in defoliating a tree. Their extensive feeding on trees can weaken the tree making it more susceptible to secondary problems. There are chemical controls recommended. A systemic soil drench applied to the tree in fall will help with the leafminer stage in late spring and adults feeding later in the season. For adults emerging now sprays are recommended now. Contact your local Extension for identifying the pest and recommendations on sprays.

The outbreaks began in Siebert and then have been slowly making their way into northern region of the Golden Plains Area to Pailo and Holyoke.