Preparing and maintaining the health of your soil is the equivalent of taking your vitamins, exercising and drinking plenty of water. We take supplemental vitamins to maintain ideal nutrition, exercise allows oxygen to flow through the blood to make sure our tissue is healthy, and water replenishes our bodies and assists oxygen transport, among other vital functions. Other living organisms, including trees, plants, microbiota, and decomposers also need nutrients, oxygen and water to maintain their systems. By preparing your soil at the beginning of the growing season and carrying out a maintenance schedule for the rest of the season, your garden should maintain its health and production.
First we need to know a little bit about soil. Soil is a mixture of sand, clay, and loam, and depending on your geographic and geologic area, your soil may have a predictable composition. For those of us in the Inland Empire, particularly in the Chino Valley, our soil is clay-like. Those who live in the foothills near Upland and Rancho Cucamonga also have clay soils, but they are more likely to have rocky soil as well due to their proximity to the foothills.
Healthy soil also contains air, water, and a small amount of organic material. Loam soils are considered ideal because they are a good combination of sand and clay. The sand allows air and water to penetrate the earth, while the clay holds in nutrients and moisture. If you have clay soil, you can purchase special products at your local gardening store to amend your soil. I’ve searched several gardening blogs from the Inland Empire and it appears that people have had success with adding builder’s sand and heavy compost to their clay soils. Builder’s sand is different than ocean sand or playground sand. Builder’s sand is coarse and large-grained. Adding this to fine clay should disrupt the settling pattern of clay. Also by adding coarse and heavy compost, you will add nutrients to the soil and provide a biodegradable aggregate, which will also disrupt the settling pattern of clay.
The manner of soil preparation described above is ideal for growing vegetables. Most vegetables are annuals and are expected to germinate, flower, and produce fruit or mature within a short time frame. They can take advantage of the freshly applied organic matter before it begins to decompose further and lose its nutritional value. Their roots tend to spread quickly, but not as deep, nor as extensively as a fruit tree. If your intention is to plant vegetables, use the mixture described above to achieve optimal results. If you’re planting fruit trees, there are two schools of thought related to soil prep. Some say that compost and soil inputs should be added to the ground at the time of planting. This could give the tree a head start by having nutrients close to its roots, however, when the roots reach the native soil, they might go into shock. The second method, which we follow at IEUA, is to plant fruit trees directly into the native, clay soil. The tree may take some time acclimating to the parent soil, but its growth should proceed uninterrupted after it becomes accustomed to its surroundings.
Once you have prepared your soil, it’s time to develop a maintenance schedule. Soil maintenance for vegetable beds is fairly simple. Compost can be added to the soil prior to planting and then once more during the growing season, preferably when plants are flowering. If you do not have compost readily available, you can use plant food instead. Make sure to keep weeds pulled so they don’t consume the nutrients that were intended for your plants. Fruit trees can also be maintained by adding tree stakes to the base of the tree. About three tree stakes will suffice per tree, but make sure to read the instructions on the packaging just in case. Tree stakes or tree food should be added about three months prior to the fruiting season of your particular type of tree.
See the links below for more information on soil preparation and maintenance:
This site provides good info about clay soils and how to prepare for planting:
http://organiclifestyles.tamu.edu/vegetables/soilpreparation.html (Texas A&M University)
Although we didn’t address it, some people prefer to add lime, blood meal, and other additives to the soil to adjust the pH for particular plants. The following sites are helpful in this matter:
http://edis.ifas.ufl.edu/vh024 (University of Florida)
http://www.homesteadingtoday.com/showthread.php?t=303252 (Manure v. Bone Meal v. Blood Meal)