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March Questions &Answers Compiled by David Rodriguez County Extension Agent-Horticulture Bexar County

Extension educational programs serve people of all ages regardless of socioeconomic level, race, color, sex, religion, disability, or national origin.

Special thanks to Forrest W. Appleton and volunteers of the "Master Gardener Hotline" in support of the weekly gardening questions and answers.

Question:
Mr. Rodriguez, we have a Crossvine covered privacy fence which appears to need pruning, as we have a mixture of live and dead stems. How drastic should pruning be and when is the best time?
Answer:
James, since the Crossvine grows quite profusely, I recommend that you cut it back quite severely to remove the dead material. I would do it about the middle of February through early March.

Question: Mr. Rodriguez, is Ligustrum poisonous to livestock?
Answer:
Yes, it is. If livestock are feeding on Ligustrum, (the vegetation and berries are poisonous) the livestock has nothing else left to forage for and are trying to survive. An animal in stressed and in poor body condition that has eaten Ligustrum plant may die if enough is eaten. Show concern by moving the livestock and begin to supplemental feed.

Question: Dave, when should I set my tomato plants in the garden?
Answer:
In the San Antonio area we usually get one more cold front blow through before March 15th. Some will not set them out until after Easter Sunday to make sure. If you do set them out earlier, try to cold frame them or use grow web to try and keep the wind off of them until they are established. Once they are a foot or so tall, mulch well and remember to water during the hot season. Right now cutworms may be a problem that can be handled by placing cardboard or plastic collars around the plants stem at the base.

Question:
Mr. Rodriguez, I have a question about coffee grounds. I've been collecting them for my flower garden. How should they be used? Also, on which types of flowers?
Answer:
You can use them in several ways. Compost them with other kitchen scraps, grass clippings, and leaves and use the compost as a soil additive. Or you can incorporate them directly into the soil where they will decompose and provide the plants (and earthworms) with nutrition. Lastly, you can use them as mulch on the top of the ground.

Question:
David, when watering my outdoor pot plants the water goes right through them, thereby staining my porch. I now have saucers under each pot. I use good potting soil and do not understand why this happens. Do you have any suggestions to prevent this from happening?
Answer:
It is necessary for the potting soil to be well drained in containers and some water should run through the pot each time it is watered to keep salts from building up in the soil. Sometimes with soils of high peat content, if you allow them to get too dry it is hard to get the soil to absorb the water. When this happens it is good to let the entire pot stand in water long enough for the soil to get saturated from the bottom up. Also, consider amending the potting mix with some good grade compost.

Question:
The spot where I have to plant my shade tree is about 8-10 feet from the foundation. I read online that Chinese Pistache tree can damage the foundation? Is that true? I like the tree for color and speed of growth. Any thoughts?
Answer:
Very few foundations are damaged by tree roots. If the foundation is properly constructed there should be little if any moisture under the foundation for the trees roots to grow into. Also the lateral extent of a trees roots may be up to three times its canopy width so regardless of where the trees are planted on most lots, the roots will grow up to the foundation. The Chinese Pistache is a good tree for shade and fall color.

Question:
What ornamental tree would you recommend for a mostly sunny spot in my area? I would like the tree to be relatively fast growing and problem free. It will be in a side yard, approximately 8' x 8' area. I'd prefer evergreen, but it's not a must.
Answer:
Consider, Loquat (Eriobotrya japonica) for such an area. It is evergreen with large tropical looking leaves. It has edible fruit but infrequently as it blooms in December-January and most years these blossoms are frozen.

Question:
Mr. Rodriguez, how do I kill a banana tree?
Answer:
Banana trees (large herbs) have very shallow roots. You should be able to take a spade or sharpshooter and, after going around the plant, just pop it out of the ground. If you do not wish to do that you can cut it off at the surface of the soil and immediately paint the cut surface with undiluted concentrated glyphosate herbicide.

Question:
Yesterday I turned the soil where I want to plant a vegetable garden. I found two grub worms and lots of earth worms. Do I treat for the grub worms before planting? If so, how long do I wait to plant my vegetables?
Answer:
Don't concern yourself about the grub worms. At this time of the year they are not doing any damage and will soon turn into beetles. Unless you see four-to-six grub worms per each square foot of your garden, there is no reason to treat. Consider treating with beneficial nematodes.

Question:
My Pride of Barbados, planted last summer, looks pretty bad after the winter. Should I cut it to the ground or will it put on growth from existing limbs?
Answer:
More than likely, it was frozen to the ground but only time will tell. I recommend that you cut it back to about one foot high and wait. It should come back but may not put any new growth on that one foot high stalk. If not, cut it back all the way when you see the new growth emerging from the ground.

Question:
Mr. Rodriguez, my Mexican petunias were hit hard this last freeze and look really bad. They are mulched but the plants look dead. When can I trim them back and will they grow this spring?
Answer:
You can cut them back at this time. Look at them and see if some of the stem is still green. If so you need only to cut off above the green part. If you like, you can cut them to the ground and they will re-sprout from there.

Question:
My 30 plus year old Live Oak has pale yellow leaves with dead smaller branches inside the canopy. The sister oak nearby is dark green and healthy. How do I get professional help/diagnosis?
Answer:
I recommend that you do nothing at this time. The leaves of the live oaks are changing colors and will be dropping like snow (or feathers) soon. This is most likely just the difference in the genes of the two trees. If, after they put on new leaves, the one you are concerned about is still looking sickly, then you should consider having a certified arborist come out and look at it to give you recommendations. You can find one listed in the yellow pages under Trees or Tree Care.

Question:
What can be used to kill Bermuda grass that is invading my Asiatic Jasmine ground cover that is used as a border around my flower beds? I would like to keep the border, but NOT the Bermuda grass.
Answer:
Any one of the so called over-the-top herbicides that are grass specific and do not harm other ornamentals. These are sold at most garden centers/nurseries as Ornamec, Vantage, Poast, Grass-B-Gon, Fusilade II, and a host of others. Just tell the garden center person what you want to do and they will be able to recommend one.

Question:
Mr. Rodriguez, are there different varieties of red bud trees? If so, which one do you recommend for our area? And, are there some that grow more upright instead of spreading out?
Answer:
Yes, there are different varieties and it is important that you purchase the right one. It is the Texas/Oklahoma Redbud (Cercis canadensis var. texensis). This Redbud can handle our summer heat and is characterized by smaller leaves that are thick and leathery with a shiny dark green surface. The Eastern Redbud, which you do not want, has larger dull green, thin leaves that do not fare well in our summer heat. Size and spread are usually dependent on the growing conditions. For more information on growing Redbud trees in this part of Texas, visit this link at: http://bexartx.tamu.edu/HomeHort/F1Column/2006%20Articles/MAR5.htm

Question:
Mr. Rodriguez, what is the correct way to prune an American Beautyberry bush? Should it just be left alone? It's getting rather large in diameter.
Answer:
Unless it is offensive in some way, I recommend leaving it alone. If it is tall and scraggly, I recommend cutting it back to close to the ground. If you just want to reduce its size, you can hedge it back to the size you desire. This is usually done as the buds begin to swell in the early spring.

Question:
How can I get rid of this mistletoe? It's taking over my oak tree. If I trim the tree to almost nothing, will it grow back?
Answer:
Mistletoe is a parasite that puts its haustoria (roots) into the tree and takes its moisture and nutrients from the sap of the tree. Removing its top will not kill the haustoria and the plant will re-grow. I know of no way of killing it short of cutting off the limbs that it is growing on. See the article at
http://aggie-horticulture.tamu.edu/plantanswers/misc/parasites.html and at http://aggiehorticulture.tamu.edu/plantanswers/misc/parasites.html%20.%2038

Question:
I recently moved into a house with a poorly kept lawn, most of the St. Augustine grass is dead. Considering the mild winter and the drought of recent should I fertilize the soil and buy a pallet of grass to start over or will the drought continue, preventing me from properly watering during the first few months that are so vital to a healthy yard? Or should I keep what I have and try to make spread, I don't mind the work if it will help my yard? Please help me with some advice-I hate having the ugly yard on the block.
Answer:
I recommend that you water your lawn now at least one inch and continue to water about ½ inch every week in the absence of rainfall until next spring. Then around April 15 fertilize the lawn with 19-5-9 synthetic analysis or a 4-2-3 organic lawn fertilizer. I think that you will find that your lawn will respond and fill in nicely.

Question:
Mr. Rodriguez, how should we care for our tomato plants to get the most fruit?
Answer:
Grow the plants in large wire type cages to keep the foliage and fruit up off the ground. Keep them well watered and fertilized. When the soil dries and the plants start to wilt slightly, water them thoroughly. At the initial planting stage and every two weeks thereafter until the first fruit set, consider fertilizing with ½ cup of 19-5-9 fertilizer or 2 cups of a 4-2-3 organic analysis. There are several excellent water-soluble tomato fertilizers available as well, such as a 6-12-6 natural analysis. Treat as needed for insects and mite pests. Thump the flower clusters with your finger tip every two days during the summer for best fruit set. If the fruit begins to split or sunscald, or if the birds are ruining it, pick it just as it starts to turn pink. Let it ripen indoors and you'll have no loss of flavor or nutritional quality.