Fertilizer Types: What’s Right For You?

Today there are more and more fertilizers on the shelves. The one that’s right for you depends on your lawn and climate, the time of year, the results you want to get, what you want to put into it and simply personal choice.

Natural and Organic Fertilizers

Just as you might suspect, natural fertilizer is good, old-fashioned plant or animal waste that has been dried and composted. There are endless varieties, from municipal sewage sludge to blood meals to vegetarian seed meals. Most have distinct benefits, too.

Overfertilizing is a non-issue with natural fertilizers, since action is slow. However, they are heavy, messy, hard-to-handle and require greater quantities due to their low nitrogen percentage. They can also have a distinct “barnyard” aroma.

They can vary in efficacy due to the unreliability of microbe activity — it rises and falls with soil temperature. That means nutrients may be unavailable in early spring and late fall, when grass is actively growing. And lawns may be getting more nutrients in hot summer days, when cool-season grasses are partially dormant and should not be fed much.

Soluble Synthetic Fertilizers

These fertilizers are produced by chemical reaction, from organic or inorganic materials. Sometimes synthetic fertilizers are labeled organic, because they were synthesized from organic compounds.

These fertilizers release nutrients fast into soil and deliver a fast greenup. They’re readily available because they do not depend on microbes, like natural fertilizers do. That means they can deliver at critical time periods, with precisely known effects. They can be more affordable and lighter than natural choices due to their concentration.

However, these fertilizers demand more work. Their effects are shorter-lived, so they require more applications. They may need to be applied as many as six times a year. The high salt content of soluble synthetics also adds a possibility of fertilizer burn. Always follow recommended rates, apply to a dry lawn and water in thoroughly to avoid burning.

Controlled-Release Fertilizers

Also called timed-release or slow-release fertilizers, these combine some characteristics of natural organic and soluble synthetic choices. Some of these products contain nitrogen as part of a complex compound that breaks down slowly in the soil. Others consist of pellets made of a quick-release nitrogen compound coated with a semi-permeable resin or plastic-like material. Each time the pellets get wet, they release small amounts of nutrients through their coatings until they are fully depleted.

Both types can last three to six months, depending on the type and amount of available water. Typically, they have a high nitrogen percentage, so large quantities are unnecessary. The slow-release of nitrogen also reduces the risk of burning the lawn.

Complete Fertilizers

Complete fertilizers contain all three of the primary nutrients: nitrogen (nitrates or ammonium), phosphorus (phosphoric acid), and potassium (potash). The analysis, or ratio of each nutrients, is featured on the front of each bag.

The ratio you’ll need depends somewhat on local climate, soil conditions and the form of nitrogen. Some complete fertilizers are for general use, and others are developed for specific grass types.

Fertilizer, Herbicide, and Pesticide Combinations

Also available are fertilizers combined with herbicides for broadleaf or crabgrass control and some combined with insecticides and fungicides to control insects and diseases.

Combinations not only save considerable time, work and headaches, they also reduce the amount of material you need to use. You may even save money by buying one product instead of two or more.

However, timing can be tricky. The best option is to apply during growth cycles for the problems you want to stop, and follow directions carefully.