Gardeners know all the best dirt
  Homemade or local soil additives can be applied to maintain healthy soil

March 25, 2004
Victoria County
Master Gardener

Gardeners not only know the best dirt, they are sometimes known to add to it. Dirt, or soil, is the heart of your garden. Some of us are blessed with good soil. The rest of us must take what we have and use soil amendments to make a balanced, productive growing medium.

The past few articles in this column discussed turfgrasses and the need to test soil samples before planting, fertilizing - or over-fertilizing. Soil management in garden beds is no exception to that practice and, in fact, soil will be more productive when proper amendments, if needed, are added to it.

The most desirable garden soil is a loose, sandy loam containing 5 percent to 10 percent organic matter with about 50% percent pore space, made up of air, water and microorganisms. The optimum pH measurement is between 6.0 and 7.5. This range is best for most garden plants. This ideal soil will hold water for plants to use, but will not stay saturated if it rains heavily because it drains well.

However, much of the soil in the Victoria area is hard-packed clay, often referred to as gumbo. This is backbreaking to till and work, and slow to dry after heavy rain. In the other extreme, some gardeners contend with very sandy soil, even to the consistency of blow sand. This poor soil holds water briefly and may form a crust after rain, hindering emerging seedlings. Tilling amendments into these problem soils will, over time, counteract these undesirable traits.

One of the best soil additives is homemade. When weeds and spent plants are pulled from your garden and beds, place this green and dried material in a compost bin or tumbler. Grass clippings, leaves, and pruned material should be added, as well as vegetable and fruit peelings, coffee grounds and other kitchen waste, except meat scraps.

If you have access to livestock manure, this can be added to make good, rich compost. Use not more than 25 percent horse or cow manure or 10 percent chicken manure.

To get the microorganisms working in the beginning, you can purchase a commercial inoculant, or just add a few shovels of garden soil. The microorganisms are readily abundant in rich garden soil. When this material is kept damp and turned, it will soon decay into loose, friable compost.

Gardeners also know where to find the good dirt. The rotted hay and manure from cow pens, or an area in the pasture where cattle have been fed, is an excellent soil amendment. However, first determine if the pasture or hay being fed has been sprayed with a herbicide containing picloram. This chemical remains in the hay and even passes through to the manure. Even when decomposed, it is still capable of affecting broad-leaf garden plants for six to 12 months after application.

There are several gins in the area, and they produce cottonseed hulls as waste. These are relatively high in nitrogen and have an acid pH, so there is the added benefit of lowering the pH of alkaline soil. This material is often piled and partially decomposed when you get it. Till in this good organic matter or use the dry hulls as mulch.

We are fortunate to be close to the mushroom farm between Shiner and Gonzales. They use a growing medium of wheat straw, poultry waste, cottonseed oil and hulls, peat moss and urea. After several uses it is discarded and sold for a very reasonable price. They will load a pickup bed or trailer. It is necessary to take a tarp to cover your load to prevent the loose material from blowing out.

It will take several seasons of adding and tilling to get your soil in optimum condition. Soil with good texture is easier to work, wet or dry. The greatest benefit is providing your plants with a soil that is aerated and will hold and release nutrients and moisture over a long period of time.

So ... check your type of soil and know your dirt. Amendments as described are readily available in this area. There is every reason for you to be "in the know" in the Gardeners' Dirt.