Mark Chamblee


Garden Mulch & Shadows
Garden Mulch & Shadows

A lively understandable spirit once entertained you. It will come again. Be still. Wait.
Theodore Roethke

In preparation for our Oui Ones Garden let’s talk about dirt. Learning to grow roses or anything for that matter in Texas versus Northern Illinois was like growing plants on another planet. The soil in Northern Illinois is rich black dirt, Texas soil is something they call gumbo and is essentially clay. I could stand on a spade and dig my own planting holes in Illinois, here I need a jack hammer and a pick and “Oui” better be able to do it together.  However, with that said I was able to put in my first dream rose garden in Texas, elevated beds, drip irrigation system and the roses never knew they were growing in Texas gumbo. Here’s the real bonus to growing roses in Texas; one can sometimes see their first rose bloom as early as Saint Patrick’s Day, March 17th , while your first rose blooms around Father’s Day in June in Northern Illinois. Here are your options: do an elevated bed with garden timbers, and this can be for any flower bed. Lay out the dimensions of the bed with a string line. Remove the sod from the area and turn over the existing subsoil. Add these organic soil amendments:

A layer of each of these organics

Canadian Sphagnum Peat Moss

Well Rotted Compost

Ground Bark

Composted Manure


Garden Gypsum

Super Phosphate at about 6-8 pounds per 100 square feet of bed area.

Blend all mixture together with a rototiller. Now your plants won’t even know they are growing in Texas gumbo. The raised bed should have good drainage, roses and most plantings love lots of water but do not like to have their “feet wet” as the saying goes.

Mark Chamblee
Mark Chamblee

Converting Clay Soils 

I work extensively with the Texas Nursery and Landscape Association (TNLA) and I had an in-depth conversation with Mark Chamblee TMCNP, State Director of TNLA Region III, of Chamblee’s Rose Nursery. Chamblee’s Rose Nursery Web site address is:

The FAQ and INFO link is especially helpful and their phone number is 800-256-7673.

I talked with Mark about the phosphorus build up and clay problems in Texas soils and he suggested converting clay beds into rich planting soil by using this process. I have been starting this process, and it is working beautifully. Here is what Mark Chamblee suggests is a way to convert Texas gumbo into a bed rich in nutrients for your plantings:

Use these organic soil amendments:

Expanded Shale

Finished compost or Cotton Burr Compost

Shredded Hard Wood Mulch

Add three inches of expanded shale and work into and till into the clay until you reach 6-8” depth. Then add 3 inches of finished compost or cotton burr compost. Top with shredded hardwood mulch, the bottom inch of the hard wood becomes mulch and the microbials break down the nutrients.

Don’t be intimidated by the organics, I buy them at the local nurseries like Calloway’s and the farm and feed stores. In closing let me tell you how too much of a good thing can lead to phosphorous build up in the soils. In Illinois my garden was on the North Eastern Illinois Rose Society Garden Tour and I heard one of the most wonderful collectable phrases one could ever hope to hear “Gaga, You have perfect rose culture.” Now, this was from a scientist and board member of the rose society and I nearly swooned. I had achieved perfect rose culture more along instinctive lines and great teachers, one who called himself an octogenarian rosarian from the Libertyville, Illinois Men’s Garden Club and of course my mother. So in Texas my instincts lead me a bit astray and into high phosphorous trouble. Translation: it was a classic case of, if a little bit is good a lot is better. How did this happen? I read that horse manure was the cat’s meow for organic fertilizer. And let me tell you, these roses had already had a witch’s brew of fish emulsion, bat guano, duck manure and rotted cow manure, not all at once of course. So I was at one of my favorite haunts, the farm & feed store with you know who, Gabrielle, who was probably angling for a Breyer horse.  And I instinctively knew a horse woman when I saw her. She was dressed as a horse woman and carried herself as landed gentry so I immediately ask her if she had horses and then of course she would have or know where I could find horse manure. The next thing you know Gabrielle and I were mucking out her stalls and loading up the trunk of my Gaga-mobile with horse manure. I carefully lined the trunk with double gauge hefty garbage bags to keep the trunk immaculate of course. One cannot have horse manure spread all over one’s trunk now can one? Certainly not, and maintain any dignity no matter how much you want horse manure for the roses. I shoveled and worked my precious black gold into the beds and then something happened. Things didn’t seem right and then I read horse manure that is not seasoned properly can have critters, bad ones, and add way to much nitrogen, etc. And I have been correcting that little problem ever since. This lovely and generous horsewoman turned out to be a city council woman who also brought a pick-up truck of horse manure over on an evening that it turned out to be that I was entertaining a former retired colonel from the Pentagon, and some work associates and although not the best timing we unloaded the horse manure, talked politics, the colonel entertained everyone by cajoling the council woman for her very liberal opinions and still we had a lovely social visit in the rose garden.

Another great resourse from the Texas Nursery And Landscape Association (TNLA) and I recommend buying, is The Best of Texas Landscape Guide 2nd Edition, and it’s only $8.75. All proceeds go to support TNLA programs. I do not work for or benefit in any way from your purchase of this book. It is just a valuable resource and I use it. There are three ways to order:

1.Download order form and fax to 512-280-3012

2. Purchase online

3. Call 800-880-0343

5 thoughts on “Converting Clay Soils, How Mark Chamblee Roses Does It”

    1. Hi Chris,
      The information that Mark shared has been a treasure trove to the gardener. As you know first hand good soil is at the heart of great plants. As always thanks for your comments.

  1. Good article. I have some nasty clayey soils here to deal with. I found a bagged product called Clay Buster Soils Amendment. It works very very well along with some good compost to make things right as rain.

    1. Hi Stan,
      That’s good to know. The expanded shale was kind of expensive but as Mark says its a one time expense.
      Love your work and articles. Would you be willing to do a guest post?

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