By William Terry Kelley
University of Georgia
The first step in the process is taking a good sample.
Sampling is really quite easy. Take a clean plastic bucket and a spade and get samples 4 to 6 inches deep in four or five places in the garden. Blend the samples well in the bucket. Then take the bucket to your county University of Georgia Cooperative Extension office and ask them to submit your soil sample.
Quick feedbackIn just a few days, you'll get a report that recommends how to fertilize your garden and whether to add some lime to adjust the soil pH. In most cases, soil pH decreases over time as we use a garden spot. You have to add lime from time to time to adjust the pH. A good soil pH for most garden crops is between 6.2 and 6.8.
If your soil test results call for lime, you'll need to apply this two to three months ahead of starting your garden to be most effective. You can apply it later, though, and still do some good. Ideally, work lime into the soil when you till the garden spot.
Apply potassium and phosphorus according to the soil test recommendations. In some cases, if you've used extra fertilizer over the years ? as gardeners often do ? your garden soil may not even need phosphorus. You may not need much potassium, either. So when you fertilize, you may be able to use something like potassium nitrate or ammonium nitrate instead of the usual 10-10-10 analysis.
Rules of thumbWhile different crops in the garden have different nitrogen requirements, you can follow some general guidelines.
Heavy feeders such as cabbage, sweet corn and leafy greens will need about 5 pounds of 10-10-10 per 100 square feet. Medium feeders such as most vining crops like squash and cucumbers need about 3 pounds per 100 square feet. And light feeders like snap beans, peas and lima beans will only need about 2 pounds.
If your garden has sandier soils, divide the fertilizer into an application at planting and one to two side-dressings. On heavier soils, use half at planting and half as a side-dressing.
Look in your soil test results for indications of any minor nutrient deficiencies. Consult your UGA Extension county agent on how to correct these.
(Terry Kelley is a Cooperative Extension vegetable horticulturist with the University of Georgia College of Agricultural and Environmental Sciences.)
(Terry Kelley is a former University of Georgia Cooperative Extension horticulturist with the UGA College of Agricultural and Environmental Sciences.)