Nothing can dampen the enthusiasm of a gardener more quickly than hard-to-manage soil. Gardeners in Galveston County and surrounding counties seem to have more problems with unfavorable soil conditions than any other single plant growing factor. Basically, though, most soils are not bad for gardening if properly prepared. Be aware that there are several measures that can be taken to improve any soil.
If the site selected is covered with turf - especially if any bermudagrass is present--then be sure to remove all lawn grass. Don't think you can dig or till this existing grass into the garden soil and get rid of it. If bermudagrass is present, even a well-tilled, pulverized garden soil can contain enough bermudagrass sprigs to cause trouble for years to come. New gardens are doomed before they begin if all bermudagrass and/or other lawn grasses are not completely removed.
Once the sod has been removed, the new garden area should be well-worked up to a depth of 8 to 10 inches. Many gardeners prefer a shovel or spading fork for working up the ground. Others, however, may want to rent a rototiller for a couple of hours or the whole day or, if possible, borrow one from a friendly neighbor. Buying one for a small garden is probably unrealistic.
If a raised garden is being considered, sod should be removed before additional soil is put into the prepared areas. Since we often receive heavy rains during the spring and soil drainage is common problem, raised beds are especially recommended where adequate soil drainage is lacking. Roots of vegetable plants grown in raised beds are far less subject to drowning due to excessive soil moisture. Given our problems with wet soils in the spring, experienced gardeners are also aware that after a rain occurs soil can be worked sooner in raised beds than soil in flat ground.
While few gardeners in Galveston County have ideal soil conditions, the physical condition of garden soils can be vastly improved by the addition of organic matter. Organic matter improves the physical properties of the soil by increasing pore volume and allowing more efficient utilization of fertilizer applications. The addition of organic matter will definitely make our heavy, gumbo clay soils more mellow and easier to work. Plant growth will also be significantly enhanced. Soil particles are less tightly packed together and the increased pore space allows excess moisture to flow through. Increased pore space in the soil also allows for better air exchange, thus improving the oxygen supply in the soil. Oxygen is vital for good plant root functions and growth. With improved soil drainage and air movement, a soil will also warm up earlier in the spring.
Materials such as compost, peat moss, shredded pine bark, or manure can be added in large amounts. When preparing new planting beds, a 3-inch to 4-inch layer tilled into existing soil is a reasonable amount. Organic matter breaks down rather quickly in our Upper Gulf Coast soils because of warm, moist weather. Hence, organic matter needs to be replenished at fairly frequent intervals. An additional means of accomplishing this is to apply organic mulch materials. Mulches provide an added benefit of moderating soil temperatures.
Another problem with many soils in this area is high pH. However, most vegetables will tolerate a relatively wide range of soil pH. A soil test can prove an invaluable tool in determining the pH of your garden soil and in letting you know what should be applied to correct its condition when warranted. When the soil is found to be excessively alkaline, the application of a soil acidifying agent can improve plant growth. The addition of fertilizer is the next step. Don't overindulge yourself in the use of fertilizer. A little is good, but too much can cause lush pant growth and reduce yields.
If you decide to purchase additional topsoil from an outside source to complete your garden preparation, try to check its source. Soil from an unchecked source may be low in price but costly in the long run, due to unwanted weed seeds or even plant disease-causing organisms such as nematodes.
Well-prepared soil is the key to healthy and productive plants. Plants grown in soil with good levels of organic matter tend to be more disease and insect resistant as well as more attractive. Whether adding peat, shredded pine bark, or your own organic compost, the effort and expense provided will reap big dividends in the growing season ahead.
This web site is maintained by Master Gardener Laura Bellmore, under the direction of William M. Johnson, Ph.D., County Extension Agent-Horticulture & Master Gardener Program Coordinator.
All digital photographs are the property of the Galveston County Master Gardener Association, Inc. (GCMGA) © 2002-2006 GCMGA - All Rights Reserved.