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Milberger's Nursery and Landscaping
3920 North Loop 1604 E.
San Antonio, TX 78247

Three exits east of 281, inside of 1604
Next to the Diamond Shamrock station
Please click map for more detailed map and driving directions.

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Weekly Gardening Column


QUESTION: We would appreciate your recommendation on which type of grass to use around our new swimming pool. The natural soil in the area is 2 to 6 inches of heavy black soil over SOLID caliche/rock. It currently supports natives such as cedars, mesquite, horseherb, bluebonnets, spiderwort, etc. We intend to backfill/top dress around the pool area (approx 2000 sq ft) with a minimum of 4 inches of high?quality topsoil (GardenVille's "4-way mix"). The pool area will have a very natural, native look ? not manicured. We intend to use sod, not seed or plugs. The area will be maintained "organically" ? we do not use pesticides/herbicides. Would zoysia, buffalo, or some other grass be best? Also, can I "seed over" these grasses with wildflower seeds or will one compete with the other?

ANSWER: I assume that the area you intend to sod with turf is in the full sun. If so, I recommend that one of the wide bladed zoysias (El Toro or JaMur) be used. These zoysias can be maintained using a regular rotary mower. Zoysia does not lend itself to overseeding. Buffalo grass would. However, buffalo will not withstand the foot traffic that you will have around the pool. And since it is ideal for overseeding with wildflowers, it will have constant weed problems the rest of the year.

QUESTION: We have recently moved into a house with several rose bushes, including a large miniature rosebush. When should these be trimmed back, they are growing tall, but not filling out. We do not know how to care for them, but want to learn. Also, there are 2 large camellia bushes. Neighbors want starts from these--how is that done?

ANSWER: Check out this PLANTanswers web site for just about everything you need to know on roses:

Camellias can be propagated by cuttings taken in mid?summer when the new growth is slightly matured. Rooting hormones should be used and the cuttings will root best under mist. See this University of Georgia web site for information on shrub propagation:

QUESTION: I have been told that there is one plant that is the "true" Yellow Rose of Texas. Could you tell me if this is so and if they are available for purchase at nurseries? If not, what yellow rose would you recommend that requires a minimum of care (suitable for planting at a cemetery)?

ANSWER: 'Harrison's Yellow" is considered by some historians to be the 'Yellow Rose of Texas' but as you will see from the article at the below URL, this rose does not do well in Texas where the growth season is long and summer temperatures are high. This article also discusses the legend of the Yellow Rose of Texas, Emily West, who was immortalized in the folksong by the same name.

Another yellow rose that you might consider for your planting is "Mrs. Dudley Cross". This is what Dr. William C. Welch says about it in his book, Perennial Garden Color. "This is a favorite of Tea rose connoisseurs. The full, pale yellow flowers are usually tinged with pink. The stems are thornless or nearly so and the foliage is exceptionally healthy and disease resistant. Color and flower shape are somewhat similar to the more modern 'Peace' rose but 'Mrs. Dudley Cross is smaller and daintier in size. This is one of the Tea roses most often found thriving in old or abandoned gardens. The flowers are excellent for cutting."

QUESTION: I have a 9- year-old water oak that is about 7.5 inches in diameter. About a month ago, sap started running from a spot about 2 feet above the ground. I took a picture to a local nursery and had a tree service come out and look at it. Both thought that I had a borer in that spot. They recommended that I attempt to push a wire through its tunnel and kill the borer and spray the tree with lindane. As I attempted to find the hole, I used a knife and removed a thin layer of bark about 2.5 inches long by 1" wide down to a layer reddish brown in color. I did not find a hole indicating a borer. However, in the middle of the area where I removed the outer bark, I could see an area about 3/8 inch in diameter running sap. This is in the same spot where the sap was running through the outer bark. What should I do next? Could this be life threatening to the tree?

ANSWER: What you describe sounds like wetwood. In the TAEX Texas Plant Diseases Handbook , found at this Aggie web site,

and looking under the section on trees we find this information:

Wetwood (bacterium ? Erwinia nimipressuralis): Affected trees exhibit a sap flow from crotches. The bark below the crotch has a water soaked appearance. The sap flow is the result of bacterial by?products producing abnormally high pressures within the vascular system. For more information on wetwood and its control, refer to the section on elms.

Wet wood or Slime Flux (bacterium ? Erwinia nimipressuralis): Chronic bleeding of sap from crotches, wound or other weakened areas of trunk, with unsightly discoloration of bark in affected area. Sap frequently is sour smelling. Bleeding or fluxing is most pronounced during spring months or during wet weather. The problem results from fermentation processes of the causal bacteria creating pressures up to 60 pounds per square inch within the tree. Tapping directly into the trunk just below the affected area to provide an outlet for abnormal sap and gasses will relieve internal pressure and may aid in recovery. Drill a small hole (one?half inch diameter or less) directly below the bleeding site and slightly upward into the center of the trunk. Install a tight fitting drainpipe in the drilled hole making sure the end of pipe extends far enough outward so that sap does not fall on the tree.

QUESTION: I have two mature Magnolia trees one in the front yard, one in back. They both have droopy under curled leaves with brown spots on the top-side of the leaves and black spots on the bottom side. Most of the leaves seem to have the spots. There are some yellow and some brown leaves on the trees and a large number of leaves on the ground. I talked to a local nursery woman about 6 weeks ago and showed her the leaves. She suggested that I water the trees at the drip-line about 15 minutes a day. I have done this, not everyday but reasonably regularly. The trees are in a lot worse condition than they were when I consulted the nursery woman. HELP!

ANSWER: There are a number of fungal leaf spot diseases that magnolias are subject to getting. They rarely cause severe damage and require no control. It is common for magnolias to lose a large amount of leaves this time of the year (and in fact they may lose all) but they will quickly replace them. See this Michigan State University Extension web site: (Magnolia Disease Problems)

Magnolias are also subject to a bacterial blight. See this Oregon State University web site for a description and an image of this disease: (Bacterial Blight)

I recommend that, if there is one available locally, you contact an arborist for his opinion and recommendations. You may also contact your local county extension agent.

QUESTION: We are already having a massive invasion of snails and slugs. Using a metaldehyde type of product with bait that works fairly well. In the back yard we have a dog and can't use this type of product and keep our dog healthy. We are using Diatomaceous earth. It is better than nothing, but not very good. Is there a better product for the back yard and is there any special technique for applying it? Also is there a better product for the non-dog areas?

ANSWER: You are dealing with one of the most frustrating pest problems, and I'm afraid I don't have a magic bullet. You are correct in exercising care with metaldehyde baits around your dog. Dogs, for some reason, are exceptionally susceptible to metaldehyde and, I am told, seem to be attracted to the bait formulations. Check out the suggestions below; I am interested in any feedback you might have.

Snails and Slugs
Snails and slugs are one of the gardener's biggest challenges. They require a truly integrated control approach, using several different tactics.

(1) Baits. Metadehyde baits kill slugs better than any other pesticide available to homeowners. Although baits will not completely eliminate these pests, they are an important control tool. When used properly, metaldehyde baits should pose limited risk to dogs or other pets, wildlife, etc. However care should be taken to avoid placing baits in such a manner that dogs (especially) can reach significant quantities.

To enhance effectiveness of baits, use during periods of dry weather and turn off the sprinkler systems for a few (3?4) days after application. Metaldehyde acts by causing intense irritation of the slug when it is either ingested or contacted. The slug responds to the metaldehyde irritation by producing a large amount of slimy mucous. Ultimately, the slug dies from loss of moisture.

Tips for keeping baits out of the reach of pets include:

** When using baits, scatter them lightly over the infested area, rather than leaving it in piles. This should reduce the attractiveness of the bait to dogs, and make it unlikely that the pet could eat a toxic amount of the product. The best place to put baits is directly between snail hiding places and their food.

** Place metaldehyde baits in locations where the dog cannot reach (e.g., in the cracks and crevices where snails and slugs hide during the day, behind prickly shrubs where the dog will not go, underneath decks, or under shelters you construct.

** Liquid bait formulations tend to last longer outdoors and may be less attractive to dogs [Feedback here would be valuable]. Deadline is one brand.

(2) Eliminate as many snail and slug hiding places as possible. Tamp down soil around edging and next to house (crevices where many slugs and snails hide); fill in spaces amongst masonry or stones with cement; fill in holes in trees with cement or expanding foam; store firewood off of ground; remove unnecessary boards, stones, weeds, ground cover, etc.

(3) Because snails and slugs are relatively long?lived, and do not reproduce quickly, intensive hand picking can be effective. Place boards, rolled up newspapers, or fruit rinds on the ground for slugs and snails to hide under, then pick the pests off and destroy. Search for snails and slugs at night or on rainy, overcast days. A week or so of intensive handpicking should have a significant impact on slug numbers.

(4)An alternative slug killer is household ammonia. A 5%
solution (1 part ammonia to 19 parts water) is reported to be a highly effective contact killer for slugs (probably not as effective for snails because of their protective shell). Spray the slugs directly at night or when they are active. You must contact the slug directly with the spray.

Beer traps will effectively catch snails and slugs. Sink a
shallow bowl or dish (old margarine tubs work well) into the ground and pour an inch or so of beer into the bottom. The beer has to be deep enough to drown the slugs. I am also TOLD that Budweiser and Michelob brands work best…J. Sugar water with a bit of yeast added also works.

(6) Nailing a strip of copper around raised bed gardens provides an effective repellent. This assumes you don't already have slugs in the raised beds. Others have reported success using 2 to 3- foot barriers of sawdust to keep slugs out of sensitive sites.

--Michael Merchant
Extension Urban Entomologist
Texas A&M Research & Extension Ctr.
17360 Coit Rd.
Dallas, TX 75252?6599
Ph.. 972-231-5362

QUESTION: I am building a small garden 8'x 8'. It is above ground, about 16 inches tall. What mix of soil will be best suited for peppers?

ANSWER: If you are going to use the native soil that you have, then you should condition it with a goodly amount of coarse sand and a lot of organic material such as compost. In the 16 inches, you should have about 6 inches of your clay, 4 inches of sand and 6 inches of compost.

If you are buying and bringing in soil, look around for a supplier that sells garden mixes and see if they have one composed of soil, sand and compost. It should be similar to the above description. You will need a little over 3 cubic yards for your project.

Which ever you choose, you need to remember that each year you will need to replenish the organic material, adding enough to bring the soil back to its original level.

QUESTION: We recently built a home in a subdivision in southwest Austin. This is the first time I've gotten to garden in Texas, I'm originally from Pennsylvania. I'm puzzled about how to prepare the ground for planting? You see, about 6 inches under the weedy topsoil is solid limestone ? ledges of it. I start digging in various places and keep hitting rock. I've dug out boulders (6' x 4' x 2') and smaller rocks but by the time I get down deep enough to remove the rock I'm 2-feet or more below the top soil. (Raised beds seem out of the question at this time because of neighborhood restrictions and easements.) Some of the boulders are so huge I can't move them. How can I plant trees and shrubs when I can't even get 6 inches down let alone the depth of the pot? (I really need to screen a view along the back fence with some shrubs but can't get to the soil.) I've bought several native Texas plant books and considered myself a good Pennsylvania gardener but I'm totally at a loss on how to handle this! Any advice-- short of moving?

ANSWER: Welcome to the challenges of gardening in the Texas Hill Country. If you cannot dig a hole sufficiently large enough to plant your transplants, the only 2 answers are to try another location or construct a raised bed. The main problem with chipping out holes in the limestone (other than the fact that there is no soil) is drainage. If you do get a hole large enough to accept your transplant, fill it with water and see how long it takes for the water to soak into the soil. All water should drain from the hole in about 24 hours or less.

You might go to your library or favorite bookstore and check out this book:

Gardening Success With Difficult Soils : Limestone, Alkaline Clay, and Caliche by Scott Ogden; Taylor Pub; ISBN: 0878337415