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May - 2009 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:
We have been trying to start Yellow Butterfly Vine and have had no luck getting it started. What is the best way to start this vine?
Answer:
This vine puts out long branches. If you let one or more of those branches lay on the ground, it will root at the nodes. When they have developed a good set of roots, cut the branch from the main vine and transplant the rooted sections to a pot or to the location you want the plant to grow.

Question:
Do you know of a good source for ornamental grasses? I am looking specifically for ruby mist Muhly. I'm in love with it and want some for a garden bed in the front of our house. I have tried the local nurseries but no luck. Their selection of ornamentals is very small.
Answer:
I can only recommend that you call around to all of the nurseries/garden centers and ask them what grasses they carry. The availability should increase as it gets consistently warmer. In addition to the Muhly, all of the Miscanthus species (Maiden Grass) and some of the Pennisetum such as Purple Fountain Grass do well in this area. In the event of a hard freeze the Fountain Grass might be killed but more likely just frozen to the roots to come back in the spring.

Question:
I'm looking for suggestions on shrubs I could plant up against the back of my house. Mostly full sun, somewhere between 3-4 feet high, flowering if possible.
Answer:
You might consider Rosemary, Blue Plumbago, Mexican Oregano or Dwarf Abelia. Japanese Boxwood or Dwarf Burford Holly are also good but would need to be pruned to keep them below 4 feet.

Question:
I just read on a web site that Plumbago are toxic. I can find only that one reference to their being toxic, and would like to know if there is any truth in it. I bought one to plant in a pot on my patio, and my cats love to sit in the sun on the patio. They also tend to run taste tests on the plants I have out there, and I am now concerned about adding the Plumbago.
Answer:
Many plants have some toxic qualities but few seem to be of concern to pets or humans. I feel sure that you have some of them in your garden or on your patio. The Blue Plumbago (Plumbago auriculata) is toxic but mainly as a skin irritant. I, and most of my neighbors, have this in our yards and it surely hasn't adversely affected the cats that come into my yard. Certainly the decision is yours as to whether or not you expose your cats to this plant.

Question:
Recently, I was digging a planting hole and down about 4 inches, I found what looked like a grub worm. This thing was huge in size, about 2 to 3 inches long. I have been gardening about 30 years and I have never seen this. Are they hurting my plants, do I need to treat them with something?
Answer:
This grub most likely was the larva of the Rhinoceros Beetle. It is
commonly located in compost piles or areas where there is an abundance of organic material. It is not harmful in any way. However, it makes good fishing bait especially for large cat.

Question:
My live oak tree has gotten very thick and needs to be thinned out. It also has low hanging branches which need to be cut back to allow foot traffic on the sidewalk. When I checked the resources, they seem to indicate that the live oak should not be pruned now but rather in the hot part of the summer (to avoid disease). Will it increase the possibility of illness, if we cut back the low hanging branches now?
Answer:
You can go ahead and prune them now. However, you should paint every wound as you prune with any latex spray paint. You do not need pruning paint as the latex will seal the wound and protect it from any sap beetles that might be in the neighborhood. Remember when pruning any plant; always have a significant reason, safety being the most important.

Question:
Is it true that egg shells, and regular coffee grinds are good for some plants? Does coffee grinds act as an acid for some plants?
Answer:
They are both beneficial additions to the compost pile. However if they are not well composted prior to use as soil amendments, they will 'steal' available nitrogen from the soil for use in the decomposition process.

Question:
What is the best way to care for a bamboo plant in regards of keeping it healthy and long lasting? Mine is starting to get yellow leaves.
Answer:
I can only assume that you are talking about a plant called Lucky Bamboo which is not a Bamboo but rather a Dracaena (Dracaena. sanderiana). The most common cause of yellow leaves in these plants is the fluoride which is added to the tap water in many areas. The use of distilled water for the plant should alleviate the problem.

Question:
Is there a difference between sweet potatoes and yams?
Answer:
Yes and no. In the southern United States, some sweet potatoes are advertised as yams, for example, Louisiana Yams. However, these are all sweet potatoes with the scientific name Ipomoea batatas. The true yam which is native to tropical regions is an unrelated plant with the scientific name Dioscorea batatas. The true yam is also called a Chinese Yam or Chinese Potato. True yams are not grown as food crops in the continental United States.

Question:
I want to grow a few rows of sweet potatoes in my garden. How do I get seed or plants?
Answer:
Sweet potatoes are started from transplants or vine cuttings rather than from seeds. Transplants, also called slips, usually grow from bedded roots. A vine cutting is 10- to 12-inch section cut from a vine growing in the field. Home gardeners can produce a limited number of slips or sections of vine by placing a sweet potato bud side up in a jar of water and placing the jar in a sunny location. Vines produced can be cut into sections and planted.

Question:
How do you know when sweet potatoes are mature and ready for harvesting?
Answer:
Sweet potatoes can be harvested at any stage of maturity. They require 100 to 140 days from planting to maturity depending on variety. Harvest sweet potatoes before the first killing frost because cool conditions can physiologically damage roots.

Question:
I am interested in information regarding the type of sweet potato you would recommend growing in South Texas. We have mostly sand and need information on amending the soil here. Any information you could provide me regarding sweet potatoes would be appreciated.
Answer:
Sweet potatoes grow best in soil that has a pH between 5.5 and 6.5. If the area where you want to plant them hasn't had frequent applications of organic material in the past, apply 1 to 2 inches of well decomposed organic matter to the area and till it in. Two to three weeks prior to planting your slips, scatter a small amount of fertilizer over the planting area (about 1/2 pound of 19-5-9 for each 35 feet of row). Sweet potatoes will do best if planted on raised beds. Use your shovel or a tiller with a bedder to form ridges and furrows, making the ridges at least 3 feet apart and 12 to 15 inches high. Then rake the top of the ridges down to where you have a planting bed about 12 inches wide and 8 inches high. As soon as the temperature 2 inches below the surface remains at least 60 degrees you should plant your slips. You should use one of these recommended Texas varieties: Beauregard, TAMU Corder, Centennial, or Jewel.

Question:
Small drops of liquid are oozing from various areas of the leaves and stems of my okra plants. What causes this?
Answer:
You are describing natural secretions from the okra plant through glands on the leaves and stems. This is a natural process of the plant and causes no damage.

Question:
How often should okra be harvested and how can you tell when it is ready?
Answer:
Okra requires frequent harvesting. For peak quality, it must be harvested before the pods become tough. Okra matures rapidly, especially in hot weather. Approximately 4 days are required from flowering to harvest maturity. Okra should be harvested every other day. Pod size will vary with variety, but length will generally be 4 to 6 inches. Test larger pods by cutting through them with a sharp knife. If it is difficult to cut through them, they are tough and unsuitable for serving. Remove old pods from the plant or it will stop producing.

Question:
Can okra plants be pruned during late summer or early fall for additional production until the first killing frost?
Answer:
Yes, but it might be best to simply make a mid-summer planting instead of pruning off spring-seeded plants. When pruned, the plants will develop a bush rather than a single stalk which usually makes harvesting difficult. Pruning should be done 80 to 100 days before the first anticipated fall frost is anticipated allowing the plants time to produce additional pods.

Question:
Can seed from this year's okra crop be saved for next year's planting?
Answer:
Yes. Okra is a self-pollinated crop and seed can be saved from one year's garden for the next. Toward the end of the season allow some of the pods to remain on the plant and harvest them when they become fully mature and almost dry. If you allow okra pods to remain on the plant and fully mature, subsequent production is greatly curtailed.

Question:
Is there anything special about the red podded varieties of okra?
Answer:
No. This is a selection or variety which produces red- colored okra. When cooked, the red color disappears and the pods take on the normal green appearance.

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