I’ve been reminding people for over two decades that, “All gardening success in Texas starts with the soil.” Somewhat sadly, we have to make those soils happen, because they don’t always occur naturally.
This message really needs to sink in with folks who have moved to this region from northern states. Up there, while you can’t garden for 5-6 months out of the year, when you can you’re able to just throw things into the existing soil and everything works.
We simply can’t do that here, because of the clay soil that abounds in the region. Some call it clay, others call it gumbo. Whatever you call it, it simply cannot sustain much plant life without being amended like nobody’s business with organic matter. I distinctly remember feeling so clever, when I wrote my first book about gardening, and the soils chapter was titled “Planting in SE Texas Gumbo – Not a Cookbook Chapter!” I learned that people passed it over, and didn’t thoroughly read it, because it came across to newcomers as a joke.
This time around, I need you to take this information very seriously. For the die-hard fans, or someone who has all my previous books, you will notice right away, that this is a compilation of everything I’ve written about soils and mulches for the past 15 years. It will focus almost exclusively on “building beds” for landscapes and vegetable gardens, with a tiny emphasis on “top dressing” for the turf. Towards the latter half, I will get even more serious about mulches. We’ll talk about the good, the bad and the ugly – of course that’s the dyed mulch.
It’s interesting to note in the evolution of building beds for this region that rose soil is still the best starting point. Before I became a garden guy on Houston radio, my predecessors and my agricultural mentors at Texas A&M University used to talk about making your own rose soil. And it was pretty sound and simple advice: Mix together equal parts loam(y) soil, sharp sand and organic matter (preferably compost, humus etc.). But honestly there weren’t many soil yards around where you could get those ingredients in bulk to blend your own.
Now, just about everyone makes a rose soil or azalea soil. There are soil yards that have “landscapers mixes” as well as “vegetable garden” mixes. You name the specifically needed planting medium these days and someone makes it in bulk and eventually in bags. So, since we’ve come a long way in the development of soils, it still baffles me why anyone would try to plant landscape material or vegetable gardens in our existing soil. I’m often equally mystified why people use peat moss or plain old potting soil in outdoor beds and landscapes.
Building The Raised Bed – Landscapes
I can make this very simple. You buy rose soil, build it up 10-12 inches and border it with some kind of stone, rock or landscape timber. Thanks! Drive safely, and we’ll see you again real soon!!! Okay, it’s a bit more detailed than that, and there are nuances along the way.
Let me start with the basic technique – tilling a few inches of rose soil into the existing soil, then building the rest of the bed on top of that. While it’s not necessary when transplanting one-gallon or smaller plants, some come in 3-, 5- and 15-gallon containers, and 10-12 inches of rose soil is simply not going to be enough depth for the 15-gallon sizes and larger. So, you’ll have to dig into the clay soil. If you till in several inches of rose soil with the existing clay, a few inches of larger transplants’ root zones will benefit from the mixed-in organic matter, and the plant will have a fighting chance of success.
Think about it this way: If I dig a hole in existing clay soil and slide a plant into it – like a shotgun shell into a gun – what do you think is going to happen to the root system as it tries to grow? And boy, do they want to grow. Let me answer that. The roots will wrap around each other and eventually just quit because there’s no place to go.
Instead, imagine a few inches of clay blended with rose soil or organic matter, then the raised bed material on top of that. A 10-gallon small shrub’s roots are just over 10 inches deep in the container. With the amended area down low and rich, friable soil in the top 8 or so inches, you’ll see how building raised beds is the key to landscaping success in our area.
Pretty much each weekend on my radio show, I hear stories from newcomers to Gulf Coast gardening like this: “Randy, I planted a knockout rose last spring, just after moving here from (fill in a state north of the Mason Dixon line), and it hasn’t grown much at all. But my neighbor’s rose is flourishing.” I’ll usually ask how it was planted, and … you guessed it … they dug a hole in the existing soil and slid the plant right in that clay tube. Have you ever looked at the delicate roots of something just slid from a container? How in the world could those feather-light roots penetrate that clay wall?
What About Existing Beds?
Over the years, many have asked me if they can convert existing beds to raised beds. The answer is complicated. It’s not just a YES or NO! So, here are some basic rules if you want to try a transformation.
First, you’ll have to extract all your existing smaller shrubs and landscape elements and start over using the bed-building tenets above.
Second, you’ll need to aerate the soil, occasionally adding good mulch, soil activators and micronutrients. You can also accomplish this over time by updating mulch levels with organic products like compost or native products at least twice a year, and poking holes occasionally with something like a piece of steel rebar or a metal rod. I also encourage spraying or even soaking in something like a soil activator or liquid organic foods a few times a year.
You can leave the larger shrubs in place and build raised beds adjacent to them, where smaller new plants and flowers have a better chance at succeeding. If the larger shrubs and trees just aren’t growing, however, re-set them and any trees using the process we call the “Twice as Wide and Half Again as Deep” method.
Building the Perfect Beds – Vegetable Gardens
I can have fun with a simple answer here as well. Mix two parts rose soil to one part quality compost, and make a raised bed of 10-12 inches. Boom! That’s all you need to know!!
Yeah, I know it’s not always that simple. But it can be. I’m not here to argue with any commercial growers about the need for raised beds in vegetable gardening. I completely understand that they incorporate sand and organic matter in the fields they have worked and amended for years. But I have to form my advice for typical homeowners in the suburbs of southeast Texas. And that means, we build raised beds, plain and simple. And when we experience warmer-than-normal winters, we also need to get busy with building vegetable beds as early as possible.
For years on GardenLine and in my books, I’ve tried to make it as easy as this: Make a raised bed of good garden soil — equal thirds of soil, sand and humus (rose soil) — as the starting point. It should be at least 6-8 inches deep, but 10-12 inches will be even better. Then, amend that with well-composted organic matter, humus or manure at about one inch (tilled in later) to every 4-6 inches of good soil.
Now there’s an even simpler recipe: Two parts rose soil to one part compost. Then, lock it in somehow. Use timbers, lumber, cinder blocks or landscape stone. Just lock it in!
Most people I know (myself included) who use this technique don’t even try to kill the grass or weeds in the area. You can suppress grass or weeds with 8-12 layers of newspaper, covered by the soils and composts. Over time, the paper will break down and become part of the soil. In the meantime, it prevents weeds and grass from growing up through your pristine vegetable garden. Best inside advice when doing this, is to wet the newspapers so they stick to the ground below, and when you start layering the dirt they don’t go moving.
You don’t have to cover the top layer with mulch, unless you want to suppress weeds and conserve moisture. But if you’re like me, I simply use compost as my mulch these days, and that’s slowly and surely adding more organic matter to the raised bed over time. There’s a lot more to learn about mulch in general and we cover that in a separate article.
While I’m at it, let me encourage you to learn from my Top 10 Rules to Live By for Vegetable Gardening in Texas. While the first key to success is the right soil and following the rest of these tenets will virtually assure your success in growing your own vegetables.
- ‘Tis better to plant a 25-cent plant in a $5 hole than a $5 plant in a 25-cent hole. (In other words, build proper beds.)
- Compost, humus or organic matter – You say tuh-mey-toh, I say tuh-mah-toh. Whatever you call it, it’s a wonderful thing. Use it!
- Ensure good drainage – With our feast-or-famine rainfall, you’ll eventually see why this is so important. Or you’ll drown your first attempt in a gully-washer.
- Let the sunshine in – Pick a spot that can provide up to 6 hours of sunshine. Filtered light won’t cut it.
- Pick proven varieties – Be sure it’s approved for our growing region. In fact, check with your County Extension Agent for proven varieties.
- Cheat Mother Nature – Because of our heat, if you can start ’em early, more power to you … especially if you’re willing to protect them on late-freeze nights.
- Control your appetite – Don’t over-plant; rein in that desire.
- Feed me, Seymore!!! – Veggies are heavy feeders (Just ask the Audrey II). The compost is a good start and a nice addition throughout, but amend that feeding with some kind of fertilizer, be it granular, liquid-organic or water-soluble.
- Keep your shadow in the garden – Get out there on a consistent basis, looking for insects, weeds and diseases. An ounce of prevention is worth a pound of cure.
- Consistency, consistency, consistency – Regular watering and repeated feedings are critical. Don’t ever allow things to dry up before you water.