What and How to Feed Plants

Garden flowers that do not attain the perfection of growth and the abundance of bloom expected may be suffering from hunger. Yet, too much fertilizer can be equally harmful. 

Commercial fertilizers are most successfully used when the amounts recommended on the package are being carefully followed. Plants burned by too much commercial fertilizer are usually beyond revival since delicate roots are affected.


 An easy way to apply fertilizer in dry form is to scatter it in a ring around the plant. The average-sized hand will hold about two ounces. After applying, the plant food can be dug in or watered into the soil. 

It is good practice to dissolve it immediately in plenty of water by soaking thoroughly with the hose.

What To Feed Plants

Apply any good plant food that will supply the elements they need for growth. Follow the directions given by the manufacturer to avoid any problems.

Confusion often arises because the home gardener reads about soil analyses, formulas, and other information intended for farmers and commercial growers. 

If we were plotting the fertilizer program for a farmer who applies $500.00 worth of fertilizer per acre to a 2,000-acre farm, such information would be of vital importance. The saving of as little as one or two points in an analysis represents substantial money.

When, however, feeding a home vegetable garden, a lawn, or small perennial planting, the difference between the costliest and the cheapest may be a matter of less than a dollar. 

Organic Versus Inorganic Foods

How to feed becomes relevant when we consider the types of plant foods available. There are two:

  • Organic (which originate as plants or animals)
  • Inorganic (made up of chemicals and minerals)

For efficient gardening, we can use both types of plant food. The organic materials, as a rule, break down rather slowly and can depend on to supply small amounts over a relatively long period.

Humus, for example, a stabilized form of organic matter, may continue to feed plants for as long as 50 years.

Organic matter should be considered when planting for a permanent effect. Once the planting finishes, the soil around the oak roots (or under the sod in a lawn) is relatively inaccessible. 

Soluble chemicals can seep down but usually cannot be depended upon for lasting effect and must be repeated at intervals during the growing season.

Beautiful lawns have been built on subsoil from a cellar excavation, merely by skillful use of chemical fertilizers. Grassroots are annual and die off in the fall, so these rots contribute organic matter, helping aeration and contributing plant food to the following year’s growth.

The one defect inherent in organic plant foods is that they do not contain nitrate nitrogen, which plants absorb from the soil. Although a few plants (notably the ericaceous group) use ammonium nitrogen, most plants require this vital element in nitrate form for average growth.

Nitrogen is found in protein form or breakdown products of protein. Plants have no teeth to grind protein from beans or steak and no stomachs to digest it. This work is carried on for them by soil bacteria. They digest protein into simpler compounds.

For this reason, organic gardening is the intensive cultivation of bacteria. These are fed and, in turn, feed the plants. As they feed, they multiply rapidly and take up protein-nitrogen, utilizing it for their life processes.

Read: 7 Tips For Making and Using Compost in the Garden

Since bacteria reproduce at a rapid rate, the amount of nitrogen locked up in their cells is enormous when figured by the acre. Because they die about as rapidly as they multiply, they are constantly releasing nitrogen into the soil.

How Bacteria Functions

Plant roots are in constant contact with the “soup” of soil moisture, in which decay releases nitrogen. They compete rather successfully with living bacteria for this element. 

All this, however, takes place only in warm soils, at temperatures above 60° degrees Fahrenheit, hence organic plant foods being relatively useless in cold soils in spring or late fall when bacteria do not thrive. 

For quicker growth in cold soils, chemical fertilizers are essential. Their nitrogen is already in nitrate form, ready to go to work at once.

Plants can use chemical plant food in early spring. Apply at the recommended rate before digging the garden. Spread on the lawn before growth begins. Any excess will be washed down the drainage or dissolved in harmless solutions before plant damage occurs.

In the case of later feeding, when plants are in active growth, it is easier to continue the use of chemical plant foods. They are cleaner, work faster and in general, give me good results. 

The inexperienced gardener may prefer to use organic fertilizers, which do not cause injury by sucking water out of the plants. If chemical fertilizers are used during the growing season, apply enough water to dissolve them completely by flushing water over the lawn or garden as soon as they are applied.

Why Fertilizer Burns

Many manufacturers of chemical plant foods like to avoid this reference to burning. This is not a drawback, but it does mean that the user must use common sense when applying. Remember, a solution of fertilizer never burns.

One form of nitrogen fertilizer – ureaform – combines the advantages of both forms. Ureaform nitrogen does not burn and a single application lasts all summer long. 

Mixed fertilizers with ureaform nitrogen are excellent for the inexperienced gardener, although rather costly.

Another possible approach to feeding plants is the use of a mixture of organic and inorganic materials. One such fertilizer combines seven different sources of nitrogen, each with its special advantage.

Related: Adding Nitrogen To The Soil 

It contains dried blood (which is one organic material that releases nitrogen almost immediately), tankage, and cottonseed meal, which release it slowly, plus chemical sources which release over a relatively long period. 

A single application of such a mixed plant food might carry a lawn on reasonably good soil through the entire growing period. So will a mixed fertilizer make with ureaform plus other ingredients?

When, however, a straight chemical plant food is used in spring, additional feedings will be needed in June, July, and August over most of the United States. If organic materials are used for these additional feedings, consider applying a little extra chemical plant food at the same time. 

Organic fertilizer will give a darker green color and work faster if about two to three pounds of ammonium sulfate are mixed with water and applied to 1,000 square feet just after the organic material is spread.