Today I learned that if soil is "worked" (tilled, turned or amended) when the soil is too wet, it turns into a brick-like substance that can take years to rehabilitate.
This weekend, Austin finally got a good, slow, soaking rain. So far, my garden's gotten a little over an inch of much-needed moisture, and some lucky ducks in Austin have enjoyed 2 or 3 inches. And after months of heat and drought, a gardener's first inclination is to run right out after a nice rain like this and turn those beds!
But as Dr. Mark McFarland, Professor and Soil Fertility Specialist at Texas Agrilife Extension explains, soil is amazingly delicate. Working a soil that is oversaturated with water alters its very structure, turning a loose, crumbly collection of granular soil particles into a compacted mass of plate-like soil particles. The damage may not be apparent until the soil dries into a thick, hardened layer of crust which is difficult for water, air, roots and seedlings to penetrate. (Walking repeatedly on soil, wet or dry, can cause the same sort of damage.)
Pea seedling poking through soil that was turned 2 weeks ago, when dry
Once the damage is done, it's difficult to remedy and requires repeated tilling of organic matter into the hardened soil over several seasons to loosen it up again. So resist the urge and wait until the soil dries a bit before giving it a workout. With our limited rainfall and warm fall temperatures, it won't take long. You can tell when the soil is ready to work by digging up a bit of soil and forming it into a ball in your hand. If the soil ball crumbles when you squeeze it, go for it. If it's muddy or smears in your hand, wait a couple of days and test again.
For more information on soil from Texas Agrilife Extension, visit their Soils and Composting page.
(Today I Learned features a nugget of information I learned during training to become a Travis County Master Gardener.)
Words and photos © 2009-2011 Caroline Homer for "The Shovel-Ready Garden". Unauthorized reproduction is prohibited.