Questions & Answers

Previous Questions & Answers
1. What is pre-emergent and when should I apply it?
2. Last year all my pecans had a little hole in the shell and a worm inside. What is it and how do I stop it from happening this year.
3. The bottom leaves of my tomato plants are turning yellow and wilting. What is the problem and will it hurt my tomatoes?
4. My tomatoes are growing fine but have a big black spot on the bottom. How do I fix this?
5. Nothing will grow under my trees, what can I do? What kind of grass will grow under my trees?
6. What can I plant that gets big, grows quickly and doesn't take any work? My neighbor just built a ___, and I don't want to look at it.
7. I have a large yard that would be too costly to water but I want green grass. How do I get the Bermuda grass to grow?
8. I had a nice lawn up until this July. Now it all seems dead. What’s up with that?
9. My Photinias have black spots all over them. What’s the matter?
10. I have white grubs under my grass leaving big brown spots. Will the grass grow back?
11. I have this huge red fuzzy ant I see every so often near my gardens. Is this a problem for my plants?
12.The flowers on my rose seem to do well up until a point, then the edges go brown and wilt. Is there a fungus or bug causing this?
13. I have aphids all over my tropical hibiscus and can’t seem to get rid of them. What should I do?
14. I have this weed that looks like grass growing in my lawn and garden beds. My regular weed killer doesn’t get rid of it. What is it?

Q. What is pre-emergent and when should I apply it?
A. In Texas we have both cold and warm weather weeds. If you can see the weeds you are trying to control it is already too late for pre-emergent control. For spring weeds applications from November to February are generally satisfactory. For winter weeds late summer, early fall is the correct application period.

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Q. Last year all my pecans had a little hole in the shell and a worm inside. What is it and how do I stop it from happening this year.
A. If you first notice the holes in late summer you probably have pecan weevil. They typically emerge between August 20th and September 10th each year. Because they over winter below the soil and pesticides cannot reach them after they have drilled into the pecans the only time for pesticide application is while they are emerging from the soil. Specific treatments of Sevin® or Fury® are recommended. Refer to bulletin L-5362.

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Q. The bottom leaves of my tomato plants are turning yellow and wilting. What is the problem and will it hurt my tomatoes?
A. Assuming the tomatoes are receiving the correct amount of water you may have a common tomato pest – the two-spotted spider mite. They generally start from the bottom of the plant and work their way up sucking juices until the leaves dry out and die. They are too small to be seen without some sort of magnifier. A miticide, such as Kelthane®, applied at the first signs is the recommended control . It is typically only available at garden shops and nurseries. Refer to bulletin XXXX.

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Q. My tomatoes are growing fine but have a big black spot on the bottom. How do I fix this?
A. You have a condition called blossom end rot. It is caused by a calcium deficiency. Even though there is sufficient calcium in the soil it becomes unavailable for use by the tomato plant. Uneven watering is generally the cause and correction almost always leads to spot free tomatoes. Water tomato plants from the bottom avoiding the leaves if possible on a daily basis maintaining a moist but not saturated soil. There are specific sprays available which may also be of benefit. Refer to Bulletin XXXXX.

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Q. Nothing will grow under my trees, what can I do? What kind of grass will grow under my trees?
A. The most shade tolerant turfgrass is St. Augustine. It will require a minimum of 4 hours of direct sun a day.

Possible alternatives:

1) If your lawn is Bermudagrass, plant Dwarf Mondo Grass sprigs, leaving about 3 or 4 inch gaps between each plant. Do not allow it to dry out the first year, and put an all purpose fertilizer (10-10-10) on it every six weeks through September. Once the Mondo Grass is established (two to three
months) you may carefully mow it at a height of three inches. Eventually the Mondo Gras will fill in and mingle in with the Bermuda. The Bermuda will choke out the Mondo in the sunny areas, and the Mondo will fill in where there is mostly shade. After the first year, water and fertilize the Mondo grass as you would an established lawn. It may take two or more years for complete coverage and it will not withstand much traffic.

2) Ground covers such as Asian Jasmine as Vinca may be planted under trees.
Water them just enough to keep the soil from getting dry the first year.
Fertilize with a genreal purpose fertilizer (10-10-10) every eight weeks the first year. Mow Asian Jasmine at a height of 2 inches in early Spring each year to get rid of gangley runners and encourage it to fill in. It will look terrible for a month or so after mowing, then seem to bolt into full folliage. Vinca may need additional irrigation during the summer, as it requires more water than the Asian Jasmine. If there is little rain or irrigation, the tree will pull most of the moisture out of the soil. If this happens, provide additional water as needed.

3) The best thing to have under a tree is a good layer of mulch. Pine bark, shredded Cypress, or any other organic mulch will keep the soil from drying out as quickly during the summer, and offer insulation from extreme temperatures in summer and winter. The mulch will break down and feed the roots of the tree. Add new mulch as needed.

If you must put some type of hardscape under your trees, make sure that it does not interfere with the tree's roots. A birdbath, birdfeeder, fountain or sculpture with a small footprint is best. Do not put down pavestones, concrete, or other materials which will not allow the tree's roots to breath. Do not raise the level of the soil more than one inch per year, from the edge of the canopy to the center of the tree. Do not lower the level of the soil, ever. Never park under a tree repeatedly, it will compact the soil and kill the roots/tree.

Let a tree be a tree, and it'll be just fine.

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Q. What can I plant that gets big, grows quickly and doesn't take any work? My neighbor just built a ___, and I don't want to look at it.
A. When planting a privacy screen, there are several things to remember. The first is that a straight row of anything looks bad. You don't want your landscape to look like a row of soldiers standing at attention. The second is that, like trees, most of the better woody plants grow slowly. That said, one of the best screens is our old faithful Eastern Red Cedar tree.
It is readily available, drought tolerant, mostly pest tolerant, and evergreen. Remember that they are trees and should be planted at least 10 feet apart. Stagger the trees so that they look as though they sprouted naturally. Even Eastern Red Cedar will need to be irrigated for at least the first year.

Even better than Cedar trees alone is a mixture of non-deciduous woody plants. The hollies are wonderful and there are numerous varieties which get quite large. Standard Burford, Nellie R. Stevens, standard Chinese, and Yaupon hollies are all nice selections. Privet and variegated Privet are also good selections. Chinese Photinia (not red tip) get very large and have few problems, other than a very strong smell when blooming. Glossy Abelia will eventually reach eight or more feet. Mountain Laurel is a good variety, but is intolerant of severe cold.

If you need to plant something that is non-toxic to livestock, Eastern Red Cedar and the Hollies are best. Privet, Abelias and Photinias are slightly toxic, and if consumed in large quantities might cause problems. Mountain Laurel is very toxic.

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Q. I have a large yard that would be too costly to water but I want green grass. How do I get the Bermuda grass to grow?
A. Bermuda grass is recommended when annual rainfall exceeds 30”. Since the average in the Rockwall area is slightly less than that some years will be good, some years will be bad. An alternative, Buffalo Grass is recommended where annual rainfall is between 15” and 30”. Another benefit is that Buffalo Grass does not require fertilization, in fact it may just promote other grasses and weeds. Refer to Bulletin XXXXX.

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Q. I had a nice lawn up until this July. Now it all seems dead. What’s up with that?
A. While Bermuda grass loves heat it can go dormant without sufficient water in mid to late summer. It is not usually something to worry about although in drought summers you may have to get out the hose and help by watering. Refer to Bulletin XXXXX.

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Q. My Photinias have black spots all over them. What’s the matter?
A. You probably have Entomossporium Leaf Spot which can also affect Indian Hawthorne, Loquat, Flowering and Fruiting Pears and Firethorn. It usually occurs in spring and fall when the plants actively growing. Clean up all the leaves on the ground around the plants and spray with fungicide generally available in any garden center. Refer to Bulletin E-175.

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Q. I have white grubs under my grass leaving big brown spots. Will the grass grow back?
A. White grubs are a common problem in the summer and fall months. They feed on the roots of all warm season grasses and can cause severe damage. There are a number of types of these grubs but the most common in Texas in the June Beetle and the Southern Masked Chafer. Damage may appear anytime between June and October. More than 5 grubs per sq. ft. generally requires chemical control. Imidacloprid and Halofenozide are the most common products used for white grub control and are available at all garden centers. Refer to our Bulletin E-211 for more information.

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Q. I have this huge red fuzzy ant I see every so often near my gardens. Is this a problem for my plants?
A. What you actually have is a Velvet Ant. They are actually a member of the wasp family and can inflict a very painful bite. They feed on ground nesting bees and wasps. Some attack beetles and flies. They are not considered a pest of plants. Refer to F@st Sheet Ent-1009.

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Q.The flowers on my rose seem to do well up until a point, then the edges go brown and wilt. Is there a fungus or bug causing this?
A. You may have thrips, a common pest of roses. XXXXXXXXXXXXXXX

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Q. I have aphids all over my tropical hibiscus and can’t seem to get rid of them. What should I do?
A. Aphids are a very common pest of many plants and come in different colors and varieties. They can infect mums, ash, barberry, box elder, crape myrtle, gardenia, oaks, oleander, pear, peach, pecans, and roses. Continuous treatment is usually required throughout the whole growing season. Numerous methods of control exist from strong streams of water sprayed to chemical control. Refer to Bulletin B-6047.

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Q. I have this weed that looks like grass growing in my lawn and garden beds. My regular weed killer doesn’t get rid of it. What is it?
A. Welcome to Texas. You are probably referring to Purple or Yellow Nutsedge sometime called Nutgrass. It is a very common and invasive weed. Since it grows so much faster than lawn grasses it is quite apparent. Very few chemicals are available for control. Image® is one product recommended for control and widely available at garden centers.
Refer to Bulletin XXXXX.

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