Back

July - 2008 Questions &Answers Compiled by David Rodriguez County Extension Agent-Horticulture Bexar County

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

Question:
David, I was given an Esperanza shrub and have selected a spot to plant it. I need to know how often the shrub can be trimmed to have beautiful blooms.
Answer:
If you remove the seed pods, it will continue to bloom. I do not recommend that you do any pruning during the growing season. If you do not receive freezing temperatures during the winter, you should cut this plant to the ground in the early spring before it begins new growth. This will keep it from getting leggy.

Question:
Mr. Rodriguez, I removed a patio deck from my backyard. I now have a large area of dirt along with a large oak tree that filters sunlight. What kind of grass seed can I sow?
Answer:
The only turfgrass that can be established from seed in our area is Bermudagrass and it does not tolerate shade. I recommend that you go to one of the nurseries that sell St. Augustine sod and buy several pieces. You can cut them up and plug them 6 inches to a foot apart and let them fill in.

Question:
Where can I buy some frog fruit ground cover? It appears to be the perfect ground cover for my purposes.
Answer:
I have never seen frog fruit (Phyla incisa) offered for sale in a nursery/garden center. You might find it in a nursery that has an extensive native plant inventory. If you keep an eye out, you can find it growing in public areas where transplants could be acquired.

Question:
We transplanted a couple of large (5 gallon) bougainvillea plants in a sunny area along our backyard fence. The plants are healthy but they have no flowers. Do I pinch the tips of the new shoots to get the plants to bloom? When and how do I fertilize them? The yard is watered by a sprinkler system.
Answer:
Bougainvillea plants are often rampant growers of vegetation at the expense of their blossoms. Here in our area, we recommend that they be grown in containers. I recommend that you do not fertilize and do not cut back on the watering.

Question:
Can Mexican Bush Sage be eaten like regular sage?
Answer:
To my knowledge there is nothing toxic about Mexican Bush Sage (Salvia leucantha). I find nothing on the internet that says that it is. This certainly does not mean that I endorse the consumption of it. Many plants, while not toxic, cause allergic reactions to many people. So, proceed with caution at your own risk!

Question:
What is causing the leaves on my Belinda's Dream roses to turn yellow?
Answer:
Even Belinda's Dream is susceptible to black spot when the conditions are right, and I suspect that this is the cause. If the leaves have black spots, turn yellow, and fall off-it's black spot. However, it will continue to grow without treatment. You can control the black spots with a fungicide like Orthonex.

Question:
I have a 4 year old Satsuma tree that has never produced fruit. It has a black smut on the leaves. What do I need to do to get it to produce fruit? And how do I get rid of the black smut on the leaves?
Answer:
First, it is probably not mature enough to produce blossoms and fruit. Your patience will take care of that. The black sooty mold on the upper surface of the leaves is caused by some sucking insect that is on the plant. It could be aphids, scale or other. You need to determine what it is before a solution can be determined. If you know what insect is causing the damage, you can use the appropriate solution for it. Only time will get rid of the black sooty mold if the damage is not by insects.

Question:
I need mulch that will not attract bugs, like termites and/or roaches. What are the pros and cons on good mulch vs. rubber mulch?
Answer:
Anything that will cover the surface of the soil and let water and air through can be considered mulch. The use of inorganic mulches such as stones, gravel, lava rock, ground up rubber, and others will do just as well as organic material such as cypress, pine bark, tree leaves, compost and others. The only benefit in using organic mulch is that as they decompose they return some nutrients and humus to the soil. All dark, moist places will attract bugs of some kind. If you keep the mulch away from the house foundation by several inches and periodically inspect the exposed foundation for termite mud tubes, termite infestation should not become a problem.

Question:
I have a large pomegranate tree in my yard that was here when I purchased the house nine years ago. It has been flowering and producing fruit each year. The pomegranate has a double red/orange flower; and one of the fruit fell into a pot and produced three plants. I planted them about three years ago and this is the first year they have bloomed. To my amazement, they have white flowers. How is that possible with the seeds coming from a red/orange flowering plant?
Answer:
Sexual reproduction in plants will reflect characteristics of both the mother and the father and some of the predecessors. The pomegranate can have scarlet, white or variegated flowers. Enjoy them.

Question:
I've been given conflicting information from different lawn care services about weed barrier and would like to know the real answer! Is it important to use a weed barrier when creating a garden? I believe it is but, I've been told that it is not.
Answer:
I don't know the real answer. However, if you are creating a garden where you will be planting seed or setting out annual vegetables or ornamental plants, the use of weed barrier cloth will just hamper your efforts. If you are planting ornamental perennials and know where you want them, its use may be of value. However, if you plan to use mulch around your plants, it becomes an unnecessary expense as the mulch will do the same job - suppressing the weeds. In my opinion, it is not necessary in any case.

Question:
Our Copper Canyon daisies are very big this year. However, they still haven't had any flowers. What can I do to help them to flower?
Answer:
Copper Canyon daisy (Tagetes lemonii) is a fall blooming perennial. The only thing you can do is have patience. It will probably be September or later before any blooms appear. While you wait, you can enjoy that very distinct aroma of the foliage.

Question:
Can carnations be grown in San Antonio? If so, where do you get the seeds or plants?
Answer:
There is one carnation that does well in South Texas, the German Red carnation. It's only sold as plants. Call some nurseries to locate the carnation plants.

Question:
I planted a Tree of Rosharon about three years ago. I have not had very much luck with it. This year I fed it blood and bone meal. The leaves got really green and had a lot of blooms. Then the blooms turned brown and fell off the tree. The leaves are turning yellow at the ends. I have seen other Tree of Rosharon that are beautiful and have many blooms. Can you please help me?
Answer:
I assume that this is an Althea/Rose of Sharon (Hibiscus syriacus). Being a hibiscus, it can drop buds and leaves quite rapidly and frequently for several reasons. Be sure that it is in a well-drained soil and that you do not over water it. Fertilize it with a high nitrogen lawn fertilizer such as 19-5-9. Spread about two cups around the plant and water it well. Also, you should cut one of those unopened flower buds; open and tap it sharply on a piece of white paper. If you see tiny, slender insects crawling around, they are thrips. These insects get into the flower buds and damage the buds. They can be controlled by spraying the plant with an insecticide containing acephate.

Question:
I have a live oak tree that has sprouts coming up from the roots. I thought they might be from acorns, but I can never find the end of the roots. I transplanted one, but it does not look like it is going to make it. Is it possible to transplant these sprouts? If so, how?
Answer:
It is not impossible, but it would be very difficult to do. The sprouts are receiving their nourishment from the massive root system of the large tree. By cutting the "lifeline," they will not have a sufficient root system of their own to survive.

Question:
For the past year and a half, I have been cutting my Zeon zoysia grass at the same height as my St. Augustine grass. I know that I should be cutting the Zoysia grass at 2 ½ inches (it's now 4 inches in height). It's like walking on thick pads, and it's very awesome. I think it may be showing some die back in areas because of the height. How do you recommend bringing the height down? Would it be too risky to do it at the heat of the summer?
Answer:
If you have been cutting your zoysia grass without catching the clippings, I suspect that you also have a thatch problem and that is what you feel when walking on it. I do not recommend that you cut it to 2 ½ inches with one mowing; you will cut off all of the green and be left with nothing but stubble. You can take it down in ½ inch increments with a couple of mowings, until you reach the desire height. Also, check it for thatch build up. If you do have thatch build up, consider renting a de-thatcher to take care of it.

Question:
Where can I take my family to pick fresh peaches?
Answer:
Consider visiting Marburger Orchard, 5 miles south of Fredericksburg off U. S. Highway 87. They are only an hour from San Antonio. The whole family will enjoy picking their own fresh peaches. For more information call them at 830-997-9433 or visit them online at: www.marburgerorchard.com.

Question:
I've heard there is a list of recommended plants for Texas called "Texas Superstars." I'm planning a new home in the country. Where can I find this list?
Answer:
The "Texas Superstars," and wonder which has been subjected to and has "passed" statewide testing, are listed at this Aggie Horticulture web site: http://aggie-horticulture.tamu.edu/cemap/frame.html. This web site links to detailed information for each plant on the list.

Question:
My tropical hibiscus was doing well; but now the leaves are yellowing and the flower buds are dropping. What's going on with my hibiscus?
Answer:
Even though it's a tropical, hibiscus can be stressed by too much heat. In the extreme heat we're having many trees employ a leaf dropping "strategy" to survive drought. Likewise, bloom for many plants may be reduced because blooming takes a lot of water and energy. Even heat-loving plants such as hibiscus can start dropping flower buds. 85 to 95 degree F. is ideal for hibiscus. 100 degree F. is too much of a good thing. Once temperatures cool, your hibiscus should recover. Meanwhile, if your hibiscuses are in containers, move those containers to a spot where they do not sustain direct afternoon sun and heat.

Question:
Can a single planting of parsley be harvested for more than one year?
Answer:
Yes. Parsley is a biennial which means it grows a plant the first year and sends up a seed stalk or flowers the second year. If grown in an area protected from excessive hot temperatures or excessive cold temperatures, parsley can be harvested well into the second year. When a flower stalk is initiated, remove it and continue harvesting the mature leaves. Parsley is a cold hardy plant and can over winter in most areas of Texas. If planted too early in the spring, cold temperatures may cause it to send up a flower stalk during its first season of growth.

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