If you have not been following my tweets, the leaf-footed plant bug that infests pomegranates, pistachios, tomatoes and almonds was reported to me about a month ago. The bugs’ numbers should be increasing at this time and ready for the devastation of your fruit trees and your vegetable garden. Cordless hand vacuum cleaners work great for sucking them up.
Q: My front and back lawn were taken over by what I call small, nettle-head weeds. Walking on them barefoot remind me of sand spurs that I saw in the South. I have been told it was Bermuda grass weed and chickweed but it doesn’t look like the pictures of chickweed I’ve seen. Could you please identify them and tell me how to get rid of them?
A: I could not recognize the weed from the pictures you sent. It has been cut back severely. This weed appears to have a long taproot like dandelion, so it could be one of the local thistles like bull or desert thistle. Whatever it is, it has a strong central taproot. This tells me it grows for more than one growing season and is probably a very poor competitor for space in your lawn.
Not the easiest, perhaps, but the best way to rid the lawn of this weed is to cut through the central taproot with a sharp knife or forked asparagus knife just below the soil surface. Regrowth of this weed is from the crown located at the top of the taproot, so cutting the taproot below this prevents it from regrowing and eventually kills it. After irrigation, perform the coup d’état.
Thistles of all sorts are difficult to control with weed killers. But nearly all weeds can be kept out of lawns by increasing the grass density. This is done by mowing high at 2½ to 3 inches, or the top setting of the mower, and fertilizing the lawn regularly.
Fertilize lawns at least four times each year with a good quality lawn fertilizer. If the lawn is tall fescue, fertilize on Valentine’s Day, Memorial Day, Labor Day and Thanksgiving. High-quality compost can be substituted and gives better results and needs applications less frequently.
Q: I have numerous horsetails planted in pots in a dry riverbed to keep them from spreading into my landscape. One of these plants appears to be dying, and I’m thinking that others will in the future. Is it because they are becoming root-bound in the pots? Can they be contained if I plant them in the ground instead?
A: Horsetail, or Equisetum as it might be called, can become root-bound the same as any plant grown in a container. All plants grown in containers must be replanted every few years when they become large. Plants that grow in clumps, like horsetail, are reduced in size through plant division. But I doubt this is the problem.
Horsetail, unlike most landscape plants, loves wet soils that drain poorly. They grow best when planted near a pond and keeping the soil wet rather than along a dry riverbed. Their native habitat is in marshes and wetlands that are constantly wet.
I think the problem is most likely dry soil, so look closely at your irrigation practices. In any case, keeping the soil wet should be your first consideration if they are not growing well.
Do not plant horsetail directly in the landscape. These plants are notorious, aggressive invaders. They will take over a landscape if it’s wet, and controlling their spread is very difficult once they are turned loose.
Growing them in containers placed in the landscape requires double potting them; the container with the plant is placed inside a second container permanently installed in the ground. This second container has a 2- to 3-inch layer of rock at the bottom to prevent the containers from lodging.
You must, must, must twist the inside container in a circle every two or three months to prevent roots or rhizomes from entering landscape through the outside container. If you don’t, the roots will grow through both containers, and the plants will establish themselves in the landscape and spread.
When dividing a bunching perennial like horsetail, remove it from the container and cut the rhizomes that connect bunches together into a single clump. This results in two or three smaller clumps. Replant one of the smaller bunches in the container with fresh soil and re-establish the irrigation. It will become a bunch again that needs to be divided in three to four years.
Q: Half of my twisted myrtles on the east side of my house are dead-looking with brown leaves. The same plants on the west side of the house are not showing the same condition. I checked the soil water levels with my water meter and they are plenty wet. Do you know what is wrong?
A: The plant is probably the Boetica twisted myrtle. It’s native to the Mediterranean region where soils are a little bit richer than our Mojave Desert soils but should do well with occasional irrigation and good soil drainage. Think rosemary, olive trees, star jasmine, Italian cypress, grapes, Spanish dagger, bay laurel and roses. These are not a true desert plant but will handle drier locations in the landscape during summer months. In fact, they like heat and sun a lot.
I’m telling you this because irrigation and soil drainage, rather than exposure to sunlight, is extremely important to these plants. These plants do not like wet soils but prefer soils that drain well and are dry after irrigations.
If soils are wet because of irrigation or poor drainage, Mediterranean plants like this one will die from root rot. If using a soil moisture meter, irrigate again after the gauge registers about “five” after dropping from “10” immediately after an irrigation.
Because they are not desert plants like agave, cacti, Texas ranger, mesquite or palo verde, be careful of surrounding them with rock in our desert climate and soils. You can get by doing that in Mediterranean climate areas of Southern California, but not in the Mojave Desert.
Q: I opened my fig fruits and there are ants inside and the fruit is rotting from the inside out.
A: Fig fruits have a small roundish opening on the bottom called the eye. Sometimes this eye is open and sometimes it’s closed, depending on the variety of the fig.
Figs that have open eyes allow entry of insects inside the fruit, which can cause problems like premature softening, an off taste or souring of the fruit. Fig fruits that have closed eyes have fewer problems for home growers than those with open eyes.
Ants have been exploring your fig tree and now have found the open eye of your fruit. As this fruit becomes sweeter, the ants have more reason to visit it.
Ants carry plant diseases with them from fruit to fruit. They can transfer bacteria or fungi that cause fruit rotting to the inside of your figs.
Either exclude or kill the ants by applying an insecticide or physically block them from getting to the fruit. Look at products such as Tanglefoot and eliminate routes the ants might use to reach the fruit. Once they find a way around an obstacle, they all will know how to do it in a short period of time.
Q: We’ve had a nice asparagus season and now my wife and I are in our annual discussion about when to stop harvesting the spears.
A: Asparagus season here usually lasts about six to eight weeks in early spring, but if the spears are bigger around than your pinky finger, then go ahead and harvest these larger ones. But not the little ones. Let them grow to their full height to rebuild the harvest for next year.
When asparagus harvest is over, the spears are allowed to fern and grow to their full height, about 5½ feet tall. These mature ferns are green and rebuild the roots or crown for the next spring harvest. These mature ferns are cut and removed when the new year starts and before the early spring harvest.
Bob Morris is a horticulture expert and professor emeritus of the University of Nevada, Las Vegas. Visit his blog at xtremehorticulture.blogspot.com. Send questions to Extremehort@aol.com.