Question: I have two problems with brown patches in my lawn. The small round ones were caused by dogs but there also are large, irregular patches that I have tried to re-seed with no luck. I have checked my sprinklers and they are getting water. How do I find the cause of the large patches and how do I fix the ones caused by the dogs?
Answer: I am assuming your lawn is a fescue lawn, which most are here. If it is a fescue lawn, then this time of year the only way to fix the dog damage is to sod these areas.
It is too hot now for seed to establish easily. Leave the damaged grass in place and reseed these spots with good quality seed in mid September or October. Do not remove the damaged grass or you will get weed invasion (probably bermudagrass) in these dead, unprotected areas of bare soil.
Just because these dead, irregular spots are getting water (because you can see the water is falling there) does not mean they are getting enough water. Lawns depend on a uniform application of water to look good. So when you apply 15 minutes of water, every spot in the lawn receives 15 minutes of water. Most lawns, even the good ones, have about a 60 percent uniformity. This means that only 60 percent of the water lands where it is supposed to; the other 40 percent lands in the wrong places. Some parts of the lawn will get its 15 minutes of water while others may only get eight, or 10 or 12.
Most lawns are much worse than 60 percent in how they apply water. When we try to follow a watering guideline with a nonuniform watering system, the areas not receiving enough water become stressed, turning a smoky, grey green due to drought and eventually turning brown.
The method commonly used to fix the areas not getting enough water is to increase the amount of water applied to the entire lawn. So instead of applying 15 minutes, the controller is increased to 20 minutes. The droughty areas of the lawn then dictate how many minutes water is applied, not the lawn.
The lawn areas receiving enough water have to be overwatered just to get enough water on the areas not getting enough. These weak areas of the water due to irrigation usually reappear in the same spots every year, unlike diseases, which may move around more year to year.
The only way to tell if the area is getting enough water is to use the screwdriver test. After irrigation, take a long screwdriver or other pointy, long instrument and push it into the good areas. The screwdriver will push easily into wet soil (provided you have soil).
Use the same screwdriver and push it into an unhealthy area. See if you can push it to the same depth. You would like to have water penetrate to about 12 inches if possible.
Sometimes people will increase the watering after the dead spots have appeared. In this case, the brown areas will appear to have enough water. However, remnants of the drought in those areas will still be present.
Grasses not getting enough water usually brown at the tips when drought is first occurring.
You will see grasses in the weak areas with brown tips if they did not receive enough water previously. At least you will see that until it is mowed.
Next month, I would start to see most of our lawn diseases start to occur, particularly during the so-called monsoon season with clouds coming up from the south and increases in humidity.
If you have had diseases in the past you might want to apply a fungicide one week prior to this time.
Q: I finally found a Golden Nugget Loquat at a local nursery after looking for a few years for this fruit plant. There was very little information at the nursery, in fact, when asked they told me they did not have any loquat plants. I accidentally found one hidden amongst the other dwarf citrus trees, but all the sign said was "12' x 6', likes morning sun or dappled shade and fruits in May." Could you tell me a little more about this plant like pests, fruiting, pruning, etc.?
A: You are lucky to find that plant here. You have a jewel. Do not plant it in a hot location. It is subtropical and would prefer to be in San Diego. East side with lots of morning sun or north side with plenty of indirect light or south side with protection from the sun after 3 p.m.
It will not like to be near a hot wall. It is very susceptible to borers primarily due to stress from heat and drought.
Leave as much foliage in the canopy and shading the trunk and limbs as you can.
The plant has very few pests other than borers, which you will have to be diligent about. I would put lots of organic mulch around it and plant it in compost-amended soil.
As you see borers, you should dig them out of the limbs and let the tree recover. I would not expect borers until the tree gets about 7- or 8-feet tall. Let it have lots of dense canopy to shade the trunk and limbs. Do not let it get droughty.
Water it like you would other fruit trees and do not put it into a rock landscape, but keep organic mulch around the plant about 3 to 4 inches deep. Feed and care for it like other fruit trees.
Visit www.crfg.org/pubs/ff/loquat.html to find more information on loquat. But information will not be provided for desert conditions.
Q: I would like to plant some fig trees. I would like to know if they are compatible to this region, what species, and any other advice like what is the best time of year to plant, if at all. I was told that they do fruit year-round.
A: This is an excellent climate for figs. Many figs will work here. At the Master Gardeners Orchard we have Black Mission, Kadota, Janice and a few others. They like moist soils though they are desert adapted and they do consume large amounts of water.
You would consider these plants more of an oasis plant rather than a desert landscape plant.
They have few pests here, but the dried fruit beetle is the worst that gets into the fruit. Sanitation (removing all old fruit from trees and the ground) usually takes care of the problem.
If your figs drop fruit, it is typically because the soil is not kept wet enough during production times. Putting organic mulch around them will help keep the soil from drying out too fast.
Planting is best in the fall, but plants may not be available. Spring is next best.
However, they can probably survive planting nearly any time of the year here if done carefully.
Prepare the soil well at the time of planting and make sure you have good drainage. Planting recommendations are the same as any other fruit tree. Protect it from rabbits with chicken wire the first few years after planting.
Q: I have just purchased a town house in Las Vegas with a grape vine in the courtyard. How do I care for it so it will produce fruit without bugs?
A: Grapes do not have a lot of pests here and most can be controlled with Dipel or Spinosad, both organic products. You will have bugs on grapes. They go hand in hand.
You will probably start spraying with either of these two products starting May 15. Spray then as needed.
Leafhoppers are a bigger problem, but usually can be tolerated, and should not be a problem in a courtyard. They cause little damage to the berries.
Do one protective spray around May 15 and a second one about three weeks later. That should be all that is needed provided you pick the fruit and keep it from getting messy. Sanitation will be key to keeping the bugs down. Do not let old fruit linger on the vine.
Bob Morris is an associate professor with the University of Nevada Cooperative Extension.
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