Bermuda grass can invade lawns when water is scarce

Let’s focus on controlling Bermuda grass this fall. Common Bermuda grass is sometimes called “devil’s grass” by old-timers. All types of Bermuda grass, from common (the weed) to hybrid Bermuda (think golf course), like heat, sunlight and water but can invade when water is scarce and other plants struggle to shade the ground.

Bermuda grass invades lawns when tall fescue lawns are mowed too short, not fertilized regularly or not watered as they should. Make sure to raise the mowing height to the highest setting, near 3 inches, when cutting tall fescue lawns and prevent Bermuda grass invasion.

Common Bermuda grass invades lawns during the warm and hot months when it is warmed by sunlight and after the lawn grass has died because of dog urine or disease. Leaving the dead grass in place rather than raking it up prevents Bermuda grass growth during the heat of summer.

During the summer months, if a lawn has brown areas, leave it alone. Let the dead grass shade the ground. Don’t clean up the dead grass until you seed or sod in the fall; otherwise Bermuda grass will invade.

Did the lawnmower, line trimmer or edger used to cut and mow your lawn just come from a lawn full of Bermuda grass weeds? If it did, that nasty Bermuda grass seed will piggyback on the tools and drop into your lawn. If someone mows your lawn, make sure they raise the mowing height and wash off their mowers and other tools before working on yours.

Everyone knows about the systemic weed killer called Roundup. If applied carefully and correctly early in the fall, it does a pretty good job killing Bermuda grass, but it can damage other plants too. Did you know substituting a weedkiller called Fusilade will not damage most trees, bushes and flowers but kill Bermuda? The actual chemical name listed in the ingredients is fluazifop-p-butyl. Similar to Roundup, it takes about 10 days before you start seeing results.

All weedkillers like Roundup and Fusilade substitute for hand weeding. You can control common Bermuda grass naturally by just removing new top growth as soon as it’s seen. If you are diligent and regular in your weeding efforts, you will get the most common Bermuda grass under control in one growing season either by regularly repeating these types of weedkillers or removing new top growth by hand. Your choice.

Q: I found desert bird of paradise in 5-gallon containers this past July and waited until fall to plant them. I think I killed them in the past by planting during the heat of summer. I want a sea of them outside my windows because they are beautiful. I would really appreciate detailed planting instructions.

A: There are three different kinds of desert bird of paradise. Except for flower color, these plants otherwise look similar and can handle the tough conditions of Las Vegas landscapes and soils.

All three survive in rock landscapes. All three prefer to be planted in soil amended with compost and watered thoroughly during planting. After establishment, they can handle just about any tough location.

Their water needs are slightly different with the Mexican bird of paradise surviving with the least care. The Mexican bird of paradise — the all-yellow one — is probably the toughest of the group.

The three bird of paradise plants produce yellow flowers, yellow flowers with red stamens (inside threads) in the center or flowers that are mostly red. Confusing, but let’s sort through them.

The bird of paradise with solid yellow flowers originates from northern Mexico and is called Mexican bird of paradise or sometimes yellow bird of paradise. It is the largest of the three types, reaching 15 to 20 feet tall or more with a similar spread. It is one of the most cold-hardy types. It can be pruned into a small tree and, if given regular irrigations, can be quite dense. Like the others, it can handle full sun.

Another cold-hardy bird of paradise with yellow flowers, also called yellow bird of paradise, is not from Mexico but South America. It has red stamens inside an otherwise yellow flower. It is shorter than the Mexican type, reaching only 10 feet tall. So stay with yellow-flowered types as they are least likely to freeze to the ground.

The third smaller but more tender desert bird of paradise has red flowers and sometimes is called the red bird of paradise or simply red bird. It also can handle desert heat and poor soil but is most likely of the three to freeze to the ground during cold winter months. It’s OK if it does because, like bougainvillea, it regrows from the ground in the spring.

Q: I purchased a small white sapote fruit tree and planted it on the north side of my home. I was wondering what I need to know to make it flourish here. There is not much information on growing it in the Mojave Desert.

A: Think “sweet oranges” when you consider growing white sapote. Parts of the country where it survives winter cold without protection are the middle to southern Florida, the Galveston area of south Texas, southern Louisiana, lower elevations of the middle to southern Arizona and coastal California. In California, it has been grown in residential areas of coastal California as far north as the Santa Barbara area. Its biggest limitations are the cold winters of Las Vegas and its hot summers and low humidity.

Las Vegas winter temperatures are similar to Raleigh, North Carolina. Our location is a bit north of where it grows best. If you have a warm microclimate around your home that allows you to grow navel oranges, then you may have a chance to grow this tree, but protect it from the cold when winter temperatures approach freezing.

It is reported to not like the high temperatures of the desert either. The north side of the home would be a good place to try growing it because of shade from the late afternoon sun.

Amend the soil at planting with good quality compost and cover the soil around it with a 4-inch layer of wood chips and water it like any other fruit tree. Cover it as you would citrus when freezing weather approaches.

Q: What causes my golden arborvitae to spread open? Too much water? Not enough water? The heat? Do you have any ideas?

A: Arborvitae is native to the wetter and colder climates of Asia. This means occasional water, not daily. Plants grow when watered. They stop growing when water is less available. Anything causing the shrub to grow too fast would cause the canopy to open.

Similar to Italian cypress, when watered too often, the stems will grow rapidly. That can cause them to become long and weak and start to flop.

So, in short, it is overwatered. But remember there are two types of overwatering: watering too frequently (such as every day) and giving it too much water at each application. If it’s overwatered, applying too much water in a single application to plants is far less damaging than watering too often.

Also, applying fertilizers too often can cause excessive growth and flopping. Installing fertilizer injectors in a landscape that continuously feed fertilizer to all the landscape plants can contribute to the problem. Continuously fertilizing plants are great for lawns, annual flowers and even vegetables but can create problems for landscape plants.

They also can begin to spread open when they get older. Many plants are more upright when young and become wider with age.

In this case, I think watering too often is the most likely culprit unless you recently installed a fertilizer injector.

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.