New nectarine variety still being tested

Q: I want to plant a Necta Zee nectarine tree. Will it do OK in Vegas? I looked on your fruit tree list and it shows it's under review.

A: Necta Zee nectarine is a relatively new release from Zaiger Genetics out of Modesto, Calif. These are the same people who developed the entire line of pluots (Flavor Supreme, Flavor Queen, Flavor King, Geopride, Flavor Finale and others). Necta Zee is a miniature nectarine, meaning the tree is small in stature (to about 6 feet they say) but still produces full-sized fruit.

You are right; it is under review at the University of Nevada Cooperative Extension Master Gardener Orchard in North Las Vegas. It is expected to do very well as a tree goes, but it is only about 3 years old and the fruit quality is unknown in our climate.

I like to see about three to five years of production from a variety of tree before I determine the quality of fruit it produces in Southern Nevada.

That being said, it is a Zaiger Genetics release so I would expect the fruit will be good to high quality. Watch for thrips damage to the fruit (scarring) in the future if you plan to go ahead with it. Fruit scarring is a common problem with all nectarines; sprays such as Spinosad help control the scarring.

Q: I have a screenlike barrier just under the top soil, and there are all sorts of weeds growing in it. My question is what can I do to prevent this in the future without killing the shrubs in this area, and what is the best method to eliminate the weeds that do emerge? I pulled and dug these and don't want to have to do that again in the future.

A: I am assuming the screenlike barrier may be a "geotextile" (fabric) used to prevent weeds (weed barrier) that might germinate and grow up underneath and through it. These are typically laid on the soil surface with 2 to 4 inches of surface mulch applied to the top of it. The surface mulch helps to shade the barrier and prevent the germination of weed seeds beneath the barrier.

We do not use black plastic for this purpose. That is a huge no-no, which is another topic in itself.

If Bermuda grass or nutgrass (both are very bad weeds here) are close to a source of water such as a drip emitter or a leaky hose, they will have no difficulty growing through the barrier and through the mulch. Although weed barriers will control many weeds, this barrier will not prevent these two specific weeds from growing through it.

The other problem with geotextile barriers covered in mulch is that windblown dirt is trapped by the rock mulch and falls on top of the barrier. Over time, this windblown dirt accumulates and forms a seedbed on top of the textile barrier in among the rocks. Weed seeds then blow over the rock mulch, fall between the rocks and accumulate on top of the barrier and germinate.

It is very common to see weeds growing on top of a weed barrier after rain. If there is a source of water, weeds will flourish and the textile barrier appears to fail. The barrier has not really failed. Many weeds below the barrier are still prevented from penetrating the barrier and making it to sunlight.

There are three things that you can do to prevent weeds from getting established on top of a geotextile barrier. The first is to make sure your sources of water are limited to only where the plants are growing. If you have water that is spraying onto the rock mulch or puddling into open areas from other sources, then you are going to have weed problems in those areas. It is imperative to make sure water is contained to only the area where plants are growing.

Secondly, it is best that mulches are deep. A 4-inch layer of mulch is much more effective at controlling weeds than a 2-inch layer. Weeds growing in coarse mulches are harder to control than weeds growing in fine mulches. By coarse mulch I mean rocks that are 1 inch or greater in diameter.

Thirdly, is a point you may not like to hear. We have an old saying, "one year of weeds leads to seven years of weeding." This just means that if you fail to control weeds in your garden area and let them go to seed, then the seeds released by these weeds will lead to seven years of future weeding. It is very important to remove weeds before they flower.

To aid the gardener, chemical companies have developed weed killers that can kill seeds as they are germinating or kill the plants after they have grown from seeds. Many of them are very effective. However, you are applying an unnatural chemical, which is potentially, and in varying degrees, dangerous to other plants, animals and your environment.

In a nutshell, there is no magic bullet except to make sure water goes directly to the plants, increase the depth of your mulch layer, stay ahead of your weeds and do not let them go to seed.

Bob Morris is a horticulture expert living in Las Vegas; he is on special assignment in the Balkh Province, Afghanistan, for the University of California, Davis. Visit his blog at xtremehorticulture.blogspot.com.