The Dirt on Dirt: The Good, The Bad and the Dirty

first published in The Goodlife Magazine


by Tom Spencer / Soul of the Garden


Ask just about any Central Texas Gardener about the soil they’re working with and you’re likely to hear a few choice expletives. Safe to say, “dirt” is as kind as it gets. I’ve had two gardens in Austin- in the first, the existing soil was really little more than gravel and construction debris. In my current garden, I am working with deep gunky clay that sticks to my shovel like glue when it’s wet and is as hard as a brick when dry. Despite being condemned to inhospitable terrain, I count my blessings- I could be gardening on rock.


The soil is the foundation of the garden. It took me years of digging and cursing to fully realize it, but gardening is all about the soil first, plants second. If we don’t start out by improving the dirt, we might as well hang up our gardening gloves and take up a saner hobby.


Folks from other parts of the country may be able to take the soil for granted, but not us. Immigrants to Central Texas are stunned by the lack of anything even resembling soil. Inga Marie Carmel, a talented landscape architect who moved here ten years ago from the West Coast remembers, “When I first got here from California, I couldn’t get over the fact that you couldn’t just plant something and walk away knowing it would grow. In California, we had thirty feet of soil- it moved, but it was there.”


Most Central Texans would be happy with thirty, or even three inches of soil. So, we are dirt-challenged on top of being drought-challenged, heat-challenged, bug-challenged, and every once in a while, flood-challenged. While we may not be able to order-up a good rain when we need it, or stop the August sun from shining, we can build our soils and heal them. One of the great joys from gardening comes not from the show of flowers or harvest of fruit, but from the simple pleasure of loose, rich, fertile soil. With hard work, and the right amendments, compost happens, so take heart.


Our region is filled with little micro-pockets of different soil types, but the vast majority of us are dealing with just two natural variations: caliche and clay. Caliche is the limey crust-like material that dominates the western half of Central Texas, sometimes it is mixed with a little clay, but it is nearly always shot through with rock. In fact, folks with caliche soils are often sitting just an inch or two above solid limestone bedrock. Clay soils dominate the eastern half of the region- the consistency and depth of the clay varies from place to place- but the challenges remain the same, it is infertile and poorly drained.


Mother Nature may have left us between a rock and a hard place, but, we have rushed in to fill in the cracks with something even worse: sandy loam, the builder’s fill-dirt from hell. I asked Selena Souders, one of the creative garden designers from Big Red Sun Nursery, about soils recently, expecting her to share horror stories about blasting through rock or having to cart in tons of compost to enliven clay. Instead, she complained about what she called, “Red death- the sandy loam that is brought in with new construction, plants hate it.’


“There are so many soil situations in Austin, and they are almost all bad,” she sighed, “on the west side, we have to recreate a landscape, build raised beds, and bring in new soil. In clay, we add organic matter trying to bring things back into balance. But, with sandy loam, sometimes you just have to remove it.”


Sandy loam- two words that just twenty years ago were repeated like a mantra. “Hey man, if you want good dirt, ask for sandy loam.”  The hype about sandy loam was so strong that it actually got codified- some city ordinances actually require sandy loam to be used as fill around septic fields and new homes.  So, what is this loam of legend and law? According to David Jones, from Whittlesey Landscape Supply, “It is dead, lifeless clay. They dig it from the bottom layer of the pits.” What does he tell customers who ask for it? “I don’t sell it.”


John Dromgoole, owner of The Natural Gardener and an organic gardening pioneer, says, “It is neither sandy nor loam, loam has organic matter. I doubt there’s any topsoil left in our area that is being sold, and if there is, you don’t want it, it’s too filled with weeds.”


Probably the best advice given to me by any of the soil gurus I talked with came from John, “Before you buy any soil, go out and see it, put it in your hand, ask questions. Don’t wait for a truck to dump it on your front yard, by then its too late.”


There is a simple lesson here- if it clumps together in your hand and looks like the modeling clay you used in kindergarten- don’t buy it!


Old gardening habits die hard- but, fortunately, old wisdom and new research have teamed up to bring the science of the soil to life- literally. Since the bad old days, ground-breaking new work (forgive the pun) has been done that really has made it possible for us to bring maximum life and fertility to our earthly inheritance. John Dromgoole is one of the folks leading the charge, as is George Altgelt from Geo Growers. Both have been working on soils and soil amendments for years- what got them started?


“Frustration,” says John, “I started out as a landscaper and wasn’t able to bid a project and do the right thing. I couldn’t find good soil- no one was composting. And I figured if I was having problems, everybody was having problems.”


“Failure,” says George, “I had plants that weren’t growing, weren’t developing roots, and I realized that soil was the problem and I didn’t know the answer.”


Altgelt’s response to his dilemma has turned into a personal quest, ask him about what makes a good soil blend and you’re likely to end up spending an entire afternoon talking about esoteric-sounding qualities like loft, paramagnetism, and microbial life. In reality though, its all dirt to him and he gladly embraces the word, “I used to say that dirt is something you wash out of your clothes- soil is something you grow plants in- but, I’ve given up on that. Now, I like to juxtapose the word dirt against all of the wonderful things it can do.”


Altgelt sells a wide variety of soil blends that consist primarily of composted dairy and organic turkey manures, and screened granite. “The granite has an almost magical quality to it,” he says, “its loaded with minerals that the plants love and has paramagnetic properties that provide a gentle energy source for the plants and soil.”


The granite also adds to the “loft” of the soil, literally its ability to breathe. In the heavy clay soils that so many of us have, this is invaluable. “Most of the work of transporting minerals and nutrients into the plant’s root system is done by air breathing microbes,” Algelt explains, “loft assures excellent gas exchange.” The composted manures in the soil mixes provide the crucial organic matter that feeds all of those microbes.


John Dromgoole has been answering people’s questions about soils for over twenty years as the host of KLBJ-AM’s Gardening Naturally, (Saturday mornings from 9-11 A.M. and Sundays from 8-10 A.M.). You’d think he’d be tired of inquiries about what it takes to make plants grow, instead, you’ll find that his passion for the good earth is fired by new discoveries. “This all about healing the land,” he says with emotion, “Our soils are so lacking in organic material, that when we add the right amendments, and feed the micro organisms, we actually heal the living system that we call the soil.”


“What’s so exciting right now,” he adds, “is that we are learning all kinds new things about how microbial activity differs from one plant community to the next. The lady who discovered this is now traveling the world healing land where chemicals no longer work.”


Dromgoole is referring to Elaine R. Ingram, from Oregon, whose research on the ‘Soil Food Web’ has revolutionized the way that people are thinking about the soil and how to improve it. “What she has taught us,” says John, “is that fungal composts work best on trees and shrubs, plants from the forest. Bacterial composts work best for the grasses and shrubs from the prairies. We’ve always needed this university-style testing, and she’s got it.”


How does this translate in The Natural Gardener’s soil yard? “Well,” says John, “we’ve been able to craft our ‘Revitalizer’ blend as a 50-50 blend of the two kinds of composts so that it will work for everybody. It also contains granite sand, calcium, gypsum and other components. The soil is really the palette for the garden, we give our customers a complete palette.”


Jill Nokes, author of How to Grow Native Plants of Texas and the Southwest, and a noted landscape designer, appreciates the commitment of both Dromgoole and Altgelt to organic soils, “I go all over the state” she says, “and I’m realizing how lucky we are to have folks like John and George here. You can’t believe how bad the stuff is they sell everywhere else. We’re really spoiled.”



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