Hoping the dead leaves and rotten tomatoes festering in your garden all winter have magically transformed into fertilizer? Possibly. But that oft-forgotten bed of mess will need a little more TLC to yield the garden you’ve been dreaming about all winter long. And you’re just in time; March is the perfect month to get down to business. According to Schlafly Bottleworks‘ master gardener and horticulturist Jack Petrovic (pictured), techniques for improving your soil range from throwing topsoil and compost on top of last year’s garden to double-digging your plot and sending soil samples to labs* for analysis. For the average home gardener, though, Petrovic suggested this user-friendly approach to getting your soil in shipshape for prime planting season.
With the enormous amount of erosion and depletion Missouri soils have suffered, we’re left with what’s referred to as “Missouri clay,” with 4 to 6 inches of topsoil in our gardens, if we’re lucky. Start by using a rake to turn over the first few inches of your topsoil. Cover the topsoil with ½ inch of compost or composted manure, and rake it in. Don’t be cheap. Be sure to buy quality compost (Or make your own.). For the cost of a new cell phone, you can have a dump truck-full of quality compost delivered to your door.
Sprinkle a Complete Organic Fertilizer (COF)** over the garden. This will add a balance of important minerals to your soil. You can also add the volcanic rock dust AZOMITE** instead of COF, or use a combination of the two.
Top the COF with a light covering of mulch or straw. If you use leaf mulch, be careful not to work it into the top layer or it will severely rob the soil of nitrogen, and growth may slow or stop for months. Just lay it on top.
Go through this process every year, preferably in the fall (but March is OK, too). Over the years, organic material will eventually leach into the deeper layers, allowing roots to grow deeper.
For a more intense approach (geared towards the more seasoned gardener), Petrovic also offered his “aggressive approach.”
Using a rake, double-dig your garden by starting at one end and digging out a strip of topsoil that’s several inches deep and 1½-feet wide. Place it in a wheelbarrow.
Take your pitchfork to the exposed portion of the garden and work up the brown clay underneath.
Dust the clay with lime (without a magnesium content), then cover it with compost or composted manure and mix it in well with a rake. I add raw, uncomposted vegetable scraps like cabbage leaves as well. Fork the topsoil from your wheelbarrow back over the strip you dug up. Repeat this procedure across your garden.
When finished, rake over the entire garden, and add a light layer of compost, manure, some coffee grounds and a dusting of Complete Organic Fertilizer (COF). Cover it all with straw or mulch. The worms will love you; the microbes will eventually readjust; and with the airspace and nutrients you just added, the plant roots will grow deep enough to continually break up the depths and sustain during the hot weather.
Know this: You will never (in your lifetime anyway) build your clay subsoil up to the point of being rich, fluffy, dark soil full of organic matter. My home garden is over 65 years old. Me, my grandfather, and my father have added truckloads of organic matter to the soil, and what I have now is dark brown instead of light brown clay.
* Petrovic recommended that no matter how you ready your garden, eventually you should get your soil tested by a professional lab. He said, “I use Logan Labs in Lakeview Ohio ($20) because the lab’s report allows me to calculate and perfectly balance the mineral content of my soil simply by going online to www.growabundant.com and plugging my results into their mineralization calculator.”
** Available at Worm’s Way, 1225 North Warson Road, Olivette, 314.994.3900, wormsway.com
Stop by Schlafly Bottleworks on the first Saturday of every month at 9 a.m. for Petrovic’s community gatherings and check out Schlafly’s Gardenworks’ Facebook page for news on upcoming gardening classes.
This article appears in March 2013.