Search For The Answer
Click here to access our database of
Plant Answers
Search For The Picture
Click here to access the Google database of plants and insects

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.

Return to Gardening Columns Main Index

Questions for the Week

Slide Show


QUESTION : I just purchased a red oak that is 3 inch in diameter. the nursery does not know what type of red oak it is. I wanted a shumard red oak -- saw it in books. It seems like every nursery I go to does not know exactly which type of species the trees are. is that a problem? my question is what should I do for it and any special care I need to do. they plant it and guarantee for 1 year..
ANSWER : It is a problem if you are planning on a Shumard red oak (Quercus shumardii) which can attain a height of 85 feet and you get a Texas red oak (Quercus texana) which will rarely get more than 35 feet tall. Perhaps you are not visiting the right nurseries. I have trouble accepting nurseries that cannot identify the plant material that they sell.

My advice for you is to follow the instructions of the nursery when they plant your tree and also get their guarantee in writing. For general instructions on planting and care of new trees see this International Society of Arboriculture article on tree planting:

QUESTION : We are students at Mason High School in Mason, Texas. We want to do a science fair project dealing with wildflowers and/or bluebonnets for our local fair, but more importantly for competition at the international level in Philadelphia this spring. Since we are in the heart of the Texas Hill Country, we are interested in doing some type of research on the beautiful wildflowers that are common in our area. We contacted Doug Welsh who gave us this website and your name as a possible mentor and advisor. We want to do something that can be built upon for the next few years as a science fair project, and we'd like to somehow be connected to TAMU research, if possible. Can you help us come up with a problem to work on? What do we do first? Do you mind helping us? Can you give us direction with this or do you have any suggestions as to where to go next? We have contacted the Wildseed Farms in Fredericksburg, and they sent us to Texas A&M University...which is how we got where we are today. We'll be anxiously waiting for your reply, hoping to be able to work with you on a wildflower/bluebonnet research project.
ANSWER : Well, it seems as if the "buck stops here" when it comes to wildflower research, doesn't it?!? I am honored that my colleagues and partners?in?wildflowers have "directed" you to me. So as not to disappoint you, I do have a suggestion for a project ?? if you want to try it. Very little has been done to identify the best strain of rhizobium to be used to grow Lupinus texensis (the hillcountry bluebonnet species). You can do a bit of investigation about rhizobium and search the Internet for available information before you undertake this effort. I can give you a brief run?down on what is known and what misinformation has been generated about rhizobium.

First of all, as you might know, rhizobium is the bacteria which forms a synergistic (organisms living together producing a mutual benefit for both) relationship with legumes (peas, beans, bluebonnets) to take nitrogen out of the air and enable legume plants to survive and thrive with little or no artificial nitrogen. Dr. Wayne Mackay, Research Horticulturist in Dallas, (Telephone: 972?231?5362) has worked with the Big Bend bluebonnet (L. harvardii) and found that it uses a different strain of rhizobium than does L. texensis (hillcountry bluebonnet) to fix or take nitrogen from the air. This indicates there are different strains of rhizobium which are most efficient from species to species. There may be different strains from region to region (from hillcountry to San Antonio area). This could be investigated by collecting strains from different regions by simply collecting soil?root nodules from bluebonnet root zones in the spring. That could be one aspect of the research. Dr. Mackay also finds that even though some rhizobium produce nodulation, the nodulation may not be actively functioning as nitrogen fixators ?? there is a simple test to determine the activity of the nodulation.

Another aspect would be testing the available sources of rhizobium on the market already to see which, if any, are effective (causes active nodulation on bluebonnet roots in non?fertilized growing areas or in container culture). Rhizobium bacteria is being commercially produced and marketed by:

Peaceful Valley Farm Supply
P. O. Box 2209
Grass Valley, California 95945
Telephone: 1?888?784?1722
They might give you other sources of commercial rhizobium. Rhizobium presently being marketed is for Lupine, alfalfa, peas, beans, etc. None have been tested for effectiveness on Texas bluebonnets. If you wanted to throw another variable into the mix, you could ask these folks what they know about mycorrihiza (another root micro?organism which enhances mineral uptake) and its availability.

Dr. Mackay in Dallas has been working with Juan Gonzales, world?renown rhizobium expert, at the University of Texas at Dallas. Tel: 972?883?2526 e?mail: I would suggest you contact him as well as Dr. Mackay to see if what I am proposing for your project is feasible. He could also offer some techniques if he would.

The contribution of this effort would allow growers (gardeners as well as commercial seed producers) of the Texas State Flower to grow better plants with less inputs.

BEWARE that there has been much mis?information written about the importance of rhizobium. Jean Andrews' first book about bluebonnets had many incorrect statements about the need for rhizobium ?? I think the second edition has "cleaned up" some of the errors. In the first edition of the book written by Jean Andrews called The Texas Bluebonnet, there is a quote which reads "If you know how to scarify seed, forget it in the case of bluebonnets except for small flower beds. As a means of helping nature along, the Texas Highway Department and the National Wildflower Research Center do not, I repeat, do not recommend the process for any of the state flowers of Texas. Getting the seed to germinate is not the problem. Nodulation is the question. You could get one thousand seeds to germinate but, if only twenty are inoculated with Rhizobium (soil bacteria which attach to roots of legumes such as bluebonnets and take nitrogen from the air), only twenty are going to bloom. This failure to form nodules is the basis for another bluebonnet misconception. Many hold the belief that bluebonnets do not bloom the first year because they have planted the seeds, watched them germinate and grow into lush plants, blooms. Nor will they bloom the second year. In fact, they will never bloom unless the seeds become inoculated with Rhizobium." This is wildflower blaspheme and literary rubbish! If, in fact, the Texas Highway Department and the National Wildflower Research Center are making statements such as these, Lady Bird had better get her some new folks! During the past fifteen years millions of bluebonnet transplants have been grown and sold in a completely sterile potting mixture with NO, I repeat, NOT ONE Rhizobium bacterium added. The seed was acid scarified with concentrated sulfuric acid before planting which would have definitely destroyed any Rhizobium. Yet all, I repeat, not some, but ALL of these transplants as well as plants from hundreds of pounds of field?planted, acid scarified seed??not treated with Rhizobium??have bloomed profusely. Rhizobium is Nature's fertilizer (nitrogen) source but if supplemental sources of fertilizer are available in a planting medium, Rhizobium is unnecessary for bloom and nodules will, in fact, not form even if seed are inoculated."

The "researchers" at the National Wildflower Institute have conducted extensive projects trying to determine the effects of rhizobium on the germination of bluebonnet seed. Their results show a beneficial effect on germination to bluebonnet seed and this information has been published in scientific journals. NOW LADIES!!! the VERY first time you quit thinking about the steps of seed growth and conclude something as DUMB as that a root?associated organism such as rhizobium has something to do with germination WHICH MUST OCCUR BEFORE THE ROOT IS EVEN PRESENT, this old boy will be off of this project before you can figure out where he went!!!!!!!!!!!!

I hope this has given you some ideas and if you want to undertake this project.

QUESTION : What do you suggest to totally rid sand burrs from a Bermuda grass lawn (ouch!!)?.
ANSWER :See the PLANTanswers article on grassbur control which can be found at this web site: article is too long to mail to you but contains everything that you need to know to control your grassburs.

QUESTION :I planted a silver maple in my back yard about four years ago. It has done okay but this year being so hot the leaves turned and fell off in August. After the rains in September It has completely leafed out again and is really pretty. My question is how often have you seen one leaf out again the same year. I came from Indiana where they are common and have never seen this before.
ANSWER :There is more difference in South Texas and Indiana than just the thousand miles ( ) between here and there. You should get used to the fact that your tree will probably defoliate early each year. Had we not had the rains in September it would have remained dormant until next spring when it would have started the cycle again. This inability to support its leaves in the heat and dryness of a typical San Antonio summer is one of the reasons why the big leafed trees like the silver maple, cottonwood, sycamore and others are not on our recommended tree lists. See the recommended landscape plant list which can be found at this PLANTanswers web site:

QUESTION : What makes a tomato turn red, especially, when the tomato is removed from the vine? As a child, I remember my grandfather and I stripping the vines in mid to late Sept. and wrapping the tomatoes in newspaper and putting them in our basement. Is it a " RED " chlorophyll or trapping gases or temperature?
ANSWER :We know that the ripening process which culminates in the red coloration is artificially initiated by the introduction of the fruits' own natural ripening hormone 'ethylene'. At this University of California?Davis web site you can find much information about the physiology of the tomato:

And from the link to 'flowers and fruit' which takes you to this web site:

And then 'pigment' will take you here:

You will find this: 'As the fruit matures the pigment changes from green to orange to red. The first pigment change is a fading of the green color due to the transformation of chloroplasts into chromoplasts resulting in a decrease in chlorophyll concentration. The initial increase in B?carotene concentration results in the orange pigment. The final red color is due to the subsequent high concentrations of lycopene.(Grierson and Kader 1986)