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September 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, my butterfly bush bloomed beautifully last year, but not one bloom this year. It looks healthy and has grown and spread out, but no blooms. What do I do to make it bloom?
Answer:
Helen, many things are late in blooming this year because of the cool, wet, cloudy spring. Your butterfly bush is probably one of them. I would not worry about it.

Question:
David, what product can I safely use to get rid of these unsightly mushrooms in my lawn? We have had rain off-and-on for the past ten days, and the mushrooms pop up daily despite my removing them from the lawn on a daily basis. I have St. Augustinegrass.
Answer:
Steven, those are harmless fungi growing on organic material in (or on) your soil and will continue to do so until the organic material is gone or the rain stops providing the environmental conditions they need to grow. You need not do anything.

Question:
Mr. Rodriguez, to conserve water, we purchased two rain barrels. They each have a screen on top, ostensibly to prevent mosquitoes from using the collected water for breeding. Unfortunately, when we lifted off the screen, a swarm of mosquitoes came out from the barrel. So what do we do? Add Clorox and if so, how much? They're 75-gallon capacity barrels. We want to be ecologically sound but not breed mosquitoes.
Answer:
Amy, consider buying a Bacillus thuringiensis (Bt), Israelensis strain product called Mosquito Dunks that will control the larva. Also you could put a small amount of vegetable cooking oil in each barrel which would stay on top of the water and suffocate the wigglers.

Question:
Dave, I dug up my small garden to a depth of about two feet this spring and added a combination of organic manure and peat. The soil was loose and deep. However, the tomatoes I place in my garden all but stop growing. The tomatoes I have in containers with mostly potting soil are outgrowing the ones in the garden by at least five times. Any thoughts on this? Remember, I am organic.
Answer:
Greg, the soil amendments that you added to the soil were not fully decomposed and are using all available nitrogen in the decomposition process. You should have added a good amount of fertilizer at the time you tilled these materials into the soil, such as a 4-2-3 analysis at a rate of two-to-three pounds per ten linear row feet. It is probably too late to do anything for the tomatoes as it is too hot for them to set fruit. Focus on your fall crop. Remember tomatoes and all vegetables are short term crops that are heavy feeders. That is great that you are organic, however you need to feed and feed often. Also, supplement by side-dressing during their growing season with one cup of slow-release 19-5-9 analysis for every ten linear row feet, once a week throughout the growing season. Water the fertilizer in thoroughly after application.

Question:
Mr. Rodriguez, what can I plant to repel snails? I have put out snail-and-slug bait, and it helped, but since they eat some plants and leave the other plants alone, I decided, I would plant things that would repel them. They climb on my garden statuary which is a type of resin, not concrete--why?
Answer:
Greg, I know of no plants that repel snails. They are just attracted to some plants and not to others. I do not have a list of plants that are not included in their diet. The current snail-and-slug baits are not nearly as effective as the ones that used to be sold. I think that if you look closely, you will find that they climb anything that is available especially when the rains come as frequently as they have recently. I wish I had a good answer but I am fighting them as well (and not winning)!

Question:
Mr. Rodriguez, I bought this house in February and it had several beautiful airplane plants just growing in the ground. I dug up two of them and put them in planters. One is doing great, but the other has brown tips on the leaves. What is causing that and what can I do? The plants are outside and we have had tremendous rain for two weeks, but all are fine except that one plant.
Answer:
Steve, the most common cause of brown tips on leaves in container plants is the build up of salts from the fertilizer used. This is exacerbated if the container does not drain properly, or if when you water, you do not apply enough to cause it to run out the bottom of the container. By letting water run through the soil in the container the salts will be flushed out.

Question:
David, is there any way to keep the recently pruned areas of our crape myrtles from sprouting? I have been diligently pruning off the new growth. The trees are healthy and blooming. The only problem is that they are so work intensive, and we have other things to do!
Answer:
Eric, pruning stimulates new buds to break and the sprouts to form. This is one of the reasons that the pruning you do should be to remove limbs all the way back to the next larger limb (or trunk) from which it was growing. If you can grab the sprouts and rip them from the tree, this will sometimes prevent new growth.

Question:
We have had a great deal of rain in the past month. My husband thinks our lawn (Bermuda) is looking thin and, also, we can see that the top of the grass is nice and green but underneath (bottom of grass) is brown. When my husband mows the grass the lawn will be brown. Any advice on what could be causing this or what we should do?
Answer:
Your husband is not mowing often enough and low enough. Bermuda will always do this unless mowed often at 1 ½ inch or shorter. I recommend that he mow it at that height, fertilize it with a
good lawn fertilizer, water it in if necessary. Then when it has grown about one inch, mow it again. It will get dense, weed free and pretty if he continues this routine.

Question:
Mr. Rodriguez, my passion vine is being eaten up by Gulf Fritillary caterpillars. This spring the caterpillars ate most of the leaves and buds. The vine seems to be recovering, but the caterpillars are large and many. Is there anything I can do? I love the flowers.
Answer:
Sarah, so long as you are aware that each caterpillar that you kill could have grown up to be a beautiful butterfly, you can kill them by spraying with one of the Bacillus thuringiensis (Bt) products sold at all nurseries/garden centers or plant more plants.

Question:
David, when can you dig Iris up? I would like to separate some of my bed because it is getting crowded. We just bought our home a couple of years ago, but the iris's look like they have never been thinned out.
Answer:
Elaine, iris, like most perennials, is separated during the season opposite the bloom season. Since they are spring bloomers you can separate them this fall.

Question:
Mr. Rodriguez, I had a bed of spreading petunias that was just beautiful. Then the rains came! They were fine until about the last week of rain. Now there are no flowers and the foliage is dried looking (brown). What happened? Should I trim them back to the ground?
Answer:
Sam, petunias do best in cool weather. The excessive rain coupled with the hot weather has caused the petunias to decline severely. You can cut them back but the petunias probably are not going to revive them. I recommend that you just pull them up and replace them with one of the heat loving fall plants at this time like snapdragons or calendulas.

Question:
Dave, I have a noxious weedy vine that grows up through my tall shrubs and trees on a pencil thin woody stem and completely covers them. The root has a large ball under the soil and the dark green leaves are three lobed and almost succulent. They put on berries if left to do so and the whole weed stinks to high heaven if disturbed. This year the weed seems to come up everywhere (probably due to the unusually mild wet spring). Help!!
Answer:
Bob, I think that this is a native called Treebine (Cissus incisa). If you cut the vine near its roots and immediately paint the cut trunk with an undiluted, concentrated herbicide such as RoundUp or Greenlight Complete, it should kill it. The small seedlings should be killed by spraying with one of these herbicides if you can do so without spraying desired plants.

Question:
Mr. Rodriguez is there anything I can do to the soil to help make my TAM peppers become mild? Many times they come off hotter than blue blazes and I maintain good soil moisture and fertilize when preparing the beds. I use water soluble fertilizer on fruit bearing plants. HELP! I love good peppers but sometime these suckers are way too hot.
Answer:
Lou, if all of your peppers are burning hot then you probably got transplants that were improperly marked. If you get the occasional one with the heat and the others are mild, that is a characteristic that some find exciting and others exasperating. If you deseed the peppers and cut out the rib on which the seed are attached, you will eliminate most of the capsaicin. You cannot adjust the growing conditions to change them.

Question:
David, a neighbor has a magnificent plant in her yard known to her as a Tiger Tail Plant. It is 3-4 ft. in height. Stalks grow out of the center, and the flowers are on the stalks. The flowers are orange and the petals of the flower circle the stalk. There are leaves on the stalks as well, but they are not the eye catcher. The blooms are spaced 6-10 inches apart on the stalks. Do you have any further information on this plant?
Answer:
I normally do not even try to identify a plant without a picture. However, even though I think that she has the wrong end of the wrong animal in her name of the plant, your description sounds like Lion's Ear (Leonotis leonurus).

Question:
Mr. Rodriguez, I have St. Augustinegrass planted in my back yard under Arizona Ash trees - the trees provide lots of shade; however, the grass is thinning out- I don't see any runners. On the side of my yard where the grass is in full sun for about three hours, the grass is plush and thick. Any suggestions as to the cause of the thinning?
Answer:
Lavern, I think the answer is in your question - "the trees provide lots of shade." None of the turfgrass that grow in the San Antonio area are capable of growing in dense shade, even St. Augustine. Unless you can get more sunlight to the grass by thinning out the canopy of the Ash trees, it is only going to get worse.