Landscape class focuses on efficient, useful desert designs

If you have a yard that you are not happy with, you think is a water guzzler and find no use for, you might want to take the University of Nevada Cooperative Extension’s class Landscape Design with the Desert in Mind. I designed this class to help area residents get the most out of their yards, reduce water use, decrease energy use and enjoy them more.

During the class, participants will create sensible, desert landscapes that are tailored to their needs and wants. They will create a design that can be used to build a new or redesign an old landscape.

Classes will run for eight weeks from 9 a.m. to noon Mondays and Tuesdays starting Feb. 4. All classes will be held at the extension’s Lifelong Learning Center, 8050 S. Maryland Parkway.

Sign up early because it is a very popular class. There is a fee, but participants will take home a finished landscape design.

For more information or to register, call the master gardener help line at 257-5555.

This month is the time to finish your pruning and get woody plants fertilized. Wait until March to prune tender plants or plants that bleed after pruning. If you have winter cold damage, delay pruning until you see new growth.

Put fertilizer just below drip emitters or in irrigation basins. You can use dry, loose fertilizer or fertilizer stakes. Don’t get them too close to the trunk or main stem or the fertilizer may damage the plant. Apply dry-soil iron fertilizers this month as well. If you have fruit trees, get an application of dormant oil on now.

Q: My cruciferous veggies are being eaten by very small, perhaps 3/8-inch long, 1/8-inch wide nocturnal caterpillars that thrive on Neem oil and Sevin. What are they and how do I get control them?

A: It is really tough to tell what it is without seeing the caterpillar and, in many cases, the adult. Some caterpillars are tough to tell apart but if you brought the critter in and it was a fairly common pest, we might get lucky identifying it.

If this pest is a caterpillar, you picked the wrong product to use for control. Try either spinosad (that is an ingredient in the label and not the trade name) or Bt (Bacillus thuringiensis, also called Dipel or Thuricide). If the pest is indeed a caterpillar, then either of these products will most likely control it. Both are organic products.

Q: I am from the East Coast. What gives with the weeds out here? It is dry and I have many times more weeds in my little backyard. I turned the water off in late October and still have lots of weeds.

A: I am going to take a wild guess at what weed this is because I have not seen it, but my guess would be that it is a mustard. These are winter annuals, plants that germinate in the fall, overwinter as a cluster of leaves called a rosette, and set seeds in pretty yellow flowers in the spring.

Most weeds are poor competitors with other plants. If weeds have a wide open area available, they will invade it. This is why a lawn can control weeds if it is kept mowed tall and dense.

However, once an opening in the lawn happens, weed seeds that have been lying dormant for years take the opportunity to grow, produce a flower as fast as it can and produce more seed. In the East Coast where there is more rainfall, there is typically more dense cover by other plants and these plants will outcompete the weeds.

But weeds are sneaky. They wait for that one opportunity and take advantage of it, usually growing much faster than many of our domesticated plants.

The wild mustard I mentioned earlier is a perfect example of a weed that is a great competitor. This weed just needs a little bit of water in the late summer or early fall to germinate. Once it germinates, it puts all of its energies into getting that rosette of leaves established. It then hibernates, or goes dormant, during the cold months and grows again in about early February, flowering and spitting out seeds as long as there is some moisture in the soil.

The bottom line is that if you want to keep weeds under control in the desert, you have to use other plants to outcompete for the same space. Secondly, you have to keep the plants you like healthy. This means giving them the right amount of water and appropriate fertilizers at the right times and protecting them from pests and diseases.

Surface mulches, whether they are wood, rock or plastic, help to provide competition so that weeds will not take over an area. Be careful not to put temporary mulches like many plastics under permanent mulches like wood or rock.

An exception are those weed barriers manufactured to be weed barriers. These are porous, tough and allow water and air to penetrate through the mulch to plant roots.

Another option you have is frequent mechanical cultivation around plants. The vast majority of weeds are shallow rooted and can be eliminated when they are young by using a hoe that cuts just under the soil surface. Sometimes these are called scuffle hoes or Hula hoes. The one I like most is a flat-blade, shaped like a narrow diamond, that cuts plants just below the soil surface by moving it along the soil surface.

The really bad weeds like Bermuda grass usually require a herbicide unless you can catch them with a hoe when they are very young.

Bob Morris is an associate professor with the University of Nevada Cooperative Extension. Direct gardening questions to the master gardener hot line at 257-5555 or contact Morris by e-mail at extremehort@aol.com.