Natural Lawn Fertilizer

In contrast to chemical fertilizers, natural fertilizers often contribute minerals, micronutrients and organic matter to the soil. These fertilizer products provide more complete nutrition to plants and help to improve the physical composition of the soil.

Not all natural fertilizer products can be considered to be organic, because they are often by-products of industrial processes and may contain substances that are not allowed in organic products. Some natural fertilizers, however, are certified organic; look for the "USDA Organic" designation on the label or package to be sure.

Natural fertilizers made from plants usually contain relatively high levels of nitrogen. Some of these products, such as soybean meal and alfalfa meal, are processed for use as livestock feed and are used secondarily as fertilizers. Cottonseed meal is a by-product of the cotton industry. These fertilizers are good sources of nitrogen, but alfalfa meal in particular is a good source of organic matter and micronutrients as well.

Cottonseed meal may contain residues of pesticides that have been sprayed on cotton plants; look for products that are certified to be free of pesticides.

Seaweed-based products such as kelp meal, kelp powder or liquid kelp provide tiny amounts of the macronutrients nitrogen, phosphorus and potassium, but they are rich in micronutrients. These products can be combined with other fertilizers to provide complete nutrition for plants.

Bone meal and blood meal are by-products of the meat-processing industry; the former is a good source of phosphorus, and the latter is high in nitrogen. Feather meal comes from the poultry industry; it is a good source of nitrogen, although it contains less readily available nitrogen than blood meal.

Products derived from fish waste are generally high in nitrogen. Fish emulsion is a liquid product known for its unpleasant smell, while fish meal is a dry product made from heat-treated fish waste.

Other products made from processed animal waste include bat guano, which may be high in either nitrogen or phosphorus, and composted chicken manure, which is generally high in both nitrogen and phosphorus. Composted cow manure and worm castings are also available as fertilizers. In addition to the macronutrients they supply, animal-based fertilizers are generally good sources of organic matter.

Due to excessive ammonia content, blood meal and chicken manure can burn grass if over-applied. Follow package instructions and apply suggested amounts.

Blood meal emits a smell that can possibly attract various wild animals and dogs into your yard.

Fertilizers made from powdered rock may contribute, depending on their source, different macronutrients to the soil. Greensand, for example, is high in potassium, and soft rock phosphate provides a source of phosphorus.

Lawns characterized as high-maintenance require relatively high levels of nitrogen and can benefit from types of fertilizers that contain a high concentration of that macronutrient. High-maintenance lawns are those that contain fast-growing, and even potentially invasive, grass species such as Kentucky bluegrass (Poa pratensis), which is hardy in U.S. Department of Agriculture plant hardiness zones 2 to 6, and perennial ryegrass (Lolium perenne), which is hardy in USDA zones 3 to 6.

Low-maintenance lawns and grass grown in shady areas require roughly half as much nitrogen as high-maintenance lawns, and they do well when fertilized with products that contain a lower concentration of nitrogen. Low-maintenance lawns contain slower-growing species such as creeping red fescue (Festuca rubra), which is hardy in USDA zones 3 to 7.

Needs for other macronutrients should be determine by a soil test.

Soil test kit

Soil sample

Test results

Fertilizer product labels

Obtain a soil test kit from your local extension service and take a sample from your lawn as directed. The results of the test will tell you which macronutrients are present in your lawn's soil and how much of each nutrient is available to the grass.

Review the results of the soil test to determine the nutritional needs of your turf grass. For example, if your soil is not nitrogen deficient, applying too much nitrogen can lead to poor root growth, so you want to avoid high-nitrogen fertilizers.

Check the label on each fertilizer product to determine the proportion of macronutrients it contains, and choose a fertilizer that accommodates your soil's deficiencies. A fertilizer label lists three numbers in sequence that indicate the proportion of nitrogen, phosphorus and then potassium. For example, a fertilizer labeled 10-6-2 contains 10 percent nitrogen, 6 percent phosphorus and 2 percent potassium by weight.