How to deal with the top troubles keeping North Texas gardeners on edge right now
I apparently was born to solve problems. Or at least to give them my best efforts. And that’s what I’m going to do here today. These are the top troubles that are keeping gardeners on edge currently — the pests, the paradoxes and the perplexities that are making gardening less than rewarding. Here’s what people are asking most commonly.
“I’m running my sprinklers two times per week, yet my shrubs still appear to be dry and dying. Why is that happening?”
There could be several reasons. You may have shade-loving shrubs planted in too much sun. It’s been blazing hot. (Count on me to report breaking news here!) And, just as obvious, the sprinkler heads may not be functioning properly, or they may not have enough pressure to cover the entire area. New shrub growth may block the spray. Or you may simply need to adjust the length of time that each station runs or how often the clocks come on. Obviously, we want to conserve all the water we can. If you don’t have a “smart” controller on your system, that could make a big difference and save you money to boot.
“Why are my junipers turning grayish-tan? It started at the bottoms and it’s working its way up the plants. Can they be saved?
I’ve even had landscape professionals ask this question, saying that this is the worst summer they have encountered in their clients’ landscapes. This is spider mites. I told someone on the air last weekend that spider mites are the tiniest pests we have in Texas landscapes and gardens, yet they do the most damage. It’s not just to junipers. They attack a wide range of hosts, from houseplants to tomatoes, shrubs to groundcovers.
Spider mites, sometimes called “red spiders,” are almost microscopic, and they do just as you described. They start their work at the bases of the plants and proceed upward. Leaves turn mottled tan, then straw-colored, then light brown and crisp. If you want to see them, thump one of the leaves or twigs that is fading to tan over a sheet of pure white paper. You’ll see very tiny specks start to move about freely. Those are the mites.
We no longer have our old standard miticide Kelthane available to us, so you’ll need to use a general-purpose insecticide that lists mites on its label. Spray top and bottom leaf surfaces, then check back a week or so later to see if you’ve gotten good control.
“Why is my St. Augustine turning solid brown? I’m watering it just like I always do.”
This is the very same thing that happened in 2022. Extremely hot weather arrived at the very same time that chinch bugs moved into St. Augustine lawns. I’m seeing scores of lawns that are browning badly, and it’s not because they aren’t being watered. It’s due to chinch bugs.
Chinch bugs are BB-sized black insects with irregular white diamonds on their backs. They will always show up in the hottest, sunniest parts of your lawn — never in the shade. The grass will appear dry, but even though you water it in the evening, it still looks dry the next morning.
That’s when you’ll need to get down on your hands and knees to part the grass and look for the chinch bugs. But don’t look in the dead areas. They’ll be right at the boundary where there’s still green grass on which they can feed. If you see them, get an insecticide labeled for their control, either granular or liquid, and get it applied right away. They can kill big parts of your lawn and leave no survivors.
“The bark is coming off my red maples and oak trees. Why? Does that mean the trees are dying?”
This is the question that keeps on giving. With red maples it’s almost always sunscald and it’s almost assuredly on the southwest or west side of the trunk. Trees that had been growing in the nursery shaded one another, even though their tops were growing in full sun. When we bought them and brought them home to plant in our landscapes, however, we planted them into full sun. Their trunks weren’t acclimated to such exposures and they overheated, then cracked and split. It takes a while, but it does happen often. The solution is to wrap the trunks the day that they’re planted and leave them wrapped for at least two years.
Oaks are also subject to sunscald. However, they, along with Chinese pistachios, suffered cold damage called “radial shake” as a result of the extreme cold of February 2021. Their bark has split vertically and fallen away in elongated sheets. Inner tissues have been exposed, and when this occurs half or more of the way around the trunk, the entire tree is commonly lost. There’s nothing you can do at this point other than give the tree the best care possible and wait to see how it all turns out. However, if the tree appears to be weakening, be forewarned that it could topple in a hurry in strong winds, and those oak branches are very heavy, capable of doing great harm and damage. If most of the foliage in the canopy has been lost, it’s probably time to call in a certified arborist to monitor the situation.
Those are but a few of the questions that are crossing gardeners’ minds. I have answers to my 1001 FAQs on my website www.neilsperry.com, or you can get outstanding localized help from a Texas Certified Nursery Professional at a member business of the Texas Nursery and Landscape Association.
