Two pounds of 5-10-5 fertilizer supplies as much nitrogen as 1 pound of 10-20-10. If a fertilizer has more nitrogen, use less. Two cups of most fertilizers will weigh about 1 pound. Use 2 pounds of fertilizer if the garden is sandy and 3 pounds if the soil is mostly clay.ĭo not use too much fertilizer. If a garden is 30 feet long and the rows are 3 feet apart, each row is almost 100 square feet. A plot 10 x 10 feet (or 5 x 20 feet) would be 100 square feet (Fig. If the garden soil has not been tested, use 2 to 3 pounds of fertilizer such as 10-20- 10 for every 100 square feet of garden area. Use 2 to 3 pounds of fertilizer such as 10-20-10 for every 100 square feet of garden area. County Extension agents can give you a soil sample container and explain where to send the sample for testing. Soil can be tested in midwinter to prepare for spring planting. From this mixture, take about ½ pint of soil for the sample (Fig. Place each handful of soil in a large container and mix. Do this in several different places in the garden. Dig down about 4 to 6 inches and take a handful of soil. To collect a soil sample, select a time when the soil is moist but not wet. A soil test clearly indicates the levels of nutrients in the soil and recommends the amounts of each nutrient to add. This is especially important for beginning gardeners who are unfamiliar with growing plants. Gardeners should have their soil tested about every 2 years. Take soil samples from several areas of the garden and mix them together. Lime adds calcium to the soil and makes it less acidic, raising pH to an acceptable level. Soils with pH levels below 5.7 need lime. They contain too much nitrogen, and many have chemicals for lawn weed control that can injure or kill vegetables. But since a slight excess of potassium will not injure plants, it is usually best to use a complete fertilizer.ĭo not use lawn fertilizers on gardens. Some soils contain enough potassium for good plant growth and don’t need more.

These fertilizers usually are easy to find. Most gardeners should use a complete fertilizer with twice as much phosphorus as nitrogen or potassium. This bag contain 13 percent nitrogen, 13 percent phosphorus, and 13 percent potassium (or potash). For example, a 50-pound bag of 10-20-10 may not cost any more than a 50-pound bag of 5-10-5 fertilizer, but the 10-20-10 bag contains twice the nutrients. Generally, higher analysis fertilizers and larger containers are less expensive. When you buy fertilizer, consider the cost per pound of the nutrient(s). A potassium shortage shows up in various ways, but stunted growth and yellowish lower leaves are common symptoms in many plants. Plants need potassium for many of the chemical processes that allow them to live and grow. Phosphorus deficiency causes stunted growth and poor flowering and fruiting. Phosphorus is needed for cell division and to help form roots, flowers and fruit. On the other hand, too much nitrogen kills plants. A lack of nitrogen causes the lower leaves to turn yellow and the whole plant to turn pale green. Nitrogen gives plants their green color and is needed to form protein. A complete fertilizer is one that includes all three elements.Īll parts of a plant need nitrogen for growth-the roots, leaves, stems, flowers and fruits. The rest of the fertilizer, or 60 pounds in this example, is a carrier or filler such as sand, perlite, or rice hulls. This equals a total of 40 pounds of nutrients.

So, a 100-pound bag of 10-20-10 fertilizer contains 10 pounds of nitrogen, 20 pounds of phosphorus, and 10 pounds of potassium. These figures are always listed in the same order. They indicate the percent of nitrogen, phosphorus and potassium in the fertilizer, respectively. The three numbers on fertilizer containers are the fertilizer analysis (Fig. They usually have a higher nutrient content. Inorganic fertilizers are man made products. Examples of organic fertilizers include manure (poultry, cow or horse), bone meal, cottonseed, or other naturally occurring materials. Plants grown in poorly drained soils, in excessive shade, or in competition with tree roots will not respond to fertilizer.įertilizers are either organic or inorganic. If plants are not growing well, fertilizing them will help only if a lack of nutrients is the cause of the problem. Nutrients come from fertilizers, compost or manure. Moisture comes from rainfall or irrigation. Plants must have light, moisture and nutrients to grow.

Best fertilizer for vegetable seedlings