Proper soil preparation far more important than your plants
Posted: Tuesday, September 18, 2012 8:00 pm
By: By Jimmy Williams
By JIMMY WILLIAMS
Special to The Messenger
You’re the type that, despite five debilitating droughts in six years, has not thrown in the garden trowel. Else, why would you be reading this gibberish?
Yes, it has been an ordeal. It may continue, but hope springs eternal, and we must keep a perspective, warped as it probably is, that things will get better.
That being said, milder days and cooler nights generally prod us into some kind of action, after crossword puzzles and Cardinal ball games under an air conditioner in a blistering summer. Soil preparation is ideally undertaken in autumn, while the ground is workable, if it hasn’t cured into concrete.
We’ve talked here before about the necessity to aerate our clay soil, but it bears repeating. Of all the things I have learned from the University of Gardening Hard Knocks throughout the past half century adequate soil preparation is, far and away, the most important.
You can plant all the azaleas, oaks or even marigolds you want into unamended red clay and you’ll be praying their last rites pronto. There is nourishment in our clay, but it must be opened up so that plants may benefit.
There are all sorts of products on the market for improving clay. “Soil conditioner” is sold in bags at discount stores and garden centers.
This is usually ground bark. When added to soil it will create air pockets that allow free distribution of nourishment, and thus roots, far afield of their original site when planted, seeking yet more nourishment. The problem with organic amendments is that they cook out relatively quickly in our heat. Come back a year later and most of it will be dissipated.
Inorganic amendments, on the other hand, stay around for awhile. Say a millenium or so, or until the rapture. Among them are sand, pea gravel, crushed rock and “chicken grit,” usually crushed oyster shells.
The latter first: chicken grit (or coarser turkey grit) is fed to fowl to line their gizzards, allowing the birds to digest grain. It can be purchased in bags from farm stores and on a small scale is an unbeatable amendment.
I once depended on coarse sand (concrete, not mortar, sand) as an amendment that would stay around. Even better is pea gravel or, preferably, crushed gravel. And so we come to filter media.
The large gravel mining operations 10 miles or so east of Paris ship thousands of tons of filter media out every day to facilities all over the southeast. Municipal water plants use the product as a filtering element, thus the name.
Filter media is red Henry County gravel that has been crushed down to about one-quarter inch or less.
Most importantly, however, is the washing of the gravel, five times at least, to remove clay and dirt. The result is clean, pure gravel. You aren’t buying any impurities.
Though the product is sold in monumental amounts, a home gardener can get a pickup or trailer load at the pits.
The vehicle will be weighed before and after loading, and the material will be priced per ton. It is cheaper than good dirt. Filter media opens up clay to a remarkable degree. When used in tandem with organic amendments (i.e. compost, leafmold, peat, manure) the result is a superb planting bed. The proportion should be about one part filter media, one part soil and one part organic amendment.
A side advantage of filter media is repelling voles and lemmings. These mouse-sized creatures do far more damage to plants than is commonly realized.
Most of us know their penchant for tulip and crocus bulbs, but they will, also, feed on the roots of numerous plants, their favorite being hostas. When they get desperate in years their numbers burgeon and they will decimate even shrub and tree roots. I have lost several large nandinas to them in the last few years, and even one specimen arborvitae.
Filter media, since it is crushed and has sharp edges, resists, but does not eliminate, voles and lemmings. They don’t like to dig around in it and cut their stinking little pink feet. I have taken to using at least one-half filter media in planting hostas.
When starting a new bed in reasonable soil, till in three inches of filter media. Till again, turning in three inches of organic amendment, then till it all again, as deeply as possible. You will then have a medium that will grow nearly anything that thrives in our climate zone.
Don’t skimp on the amendments. Your soil prep could cost as much as the plants that will go in.
Editor’s note: Jimmy Williams is the garden writer for The Paris Post-Intelligencer, where he can be contacted on Mondays at (731) 642-1162.
Published in The Messenger 9.18.12
Jimmy Williams, The Garden Path