Learn to tell if your plants are well fed by looking at your plants' leaves. As the primary food factory for plants, leaves can indicate nutrient imbalances. Too little nitrogen, for example, turns leaves yellow, while excess potassium can cause stunted growth. Learn to recognize the look of healthy leaves so you can spot the onset of any problems.
Fertilizer labels list nitrogen, phosphorus and potassium by their chemical abbreviations — N, P and K, always in that order. Labels also indicate the ratio of each element to the total mass. A 10-6-4 formulation, for example, contains 10 percent nitrogen, six percent phosphorus and four percent potassium. All fertilizers have these three numbers listed on the label.
Don't forget about micronutrients. In addition to nitrogen, phosphorus and potassium, plants need three other major nutrients—sulfur, calcium and magnesium — as well as minute amounts of trace elements, including iron, manganese, zinc, iron and copper.
A good rule of thumb is to feed plants during their most active season of growth, keeping in mind that plants vary in their fertilizer requirements. Some, such as herbs, need fertilizer infrequently; others, such as roses, are hungry all the time. Withholding fertilizer in the fall helps new growth harden off before winter.
For new beds, incorporate fertilizer when preparing the soil; simply broadcast it over the bed or row and dig it in thoroughly. For single specimens, such as a perennial, mix fertilizer into the planting hole or work it into the surface around plants. To fertilize established shrubs and trees, scratch fertilizer into the soil above the root zones. Always water thoroughly after fertilizing any plant.
Use a hammer and a large nail to punch holes in the bottom of a two-pound coffee can to make a handy spreader for powdered or granular fertilizers.
Mature trees have extensive root systems, so they often do a good job of foraging for nutrients. If you want to feed a large tree, make sure the fertilizer goes to the tree rather than to the grass or other plants growing beneath it. Use an electric or manual auger with a long, large-diameter bit—at least one foot long and 1.5 inches around—to bore deep holes. Space holes two feet apart around the drip line and make another ring of holes 2.5 feet from the trunk. Fill the holes with organic or timed-release fertilizer and water well.
Mechanical spreaders, either drop or broadcast type, make short work of fertilizing lawns or other large areas.To avoid clogs, use only dry fertilizers and keep the shut-off mechanism clean so that it can close completely.
With a drop spreader, apply fertilizer in a crisscross pattern for complete coverage, going over the same area both horizontally and vertically. Use half the recommended spread rate in each direction.
When using any type of fertilizer, always follow the application rates recommended by the manufacturer. Using more won’t boost or speed growth and may actually injure your plants.
If you have a freshwater aquarium, you can recycle the contents in the garden. When cleaning the tank, save the nutrient-rich water to pour over plants.
Use liquid food for houseplants and patio plants grown in containers because it spreads easily through the soil and is immediately available to plants.
The Reader’s Digest Association, Inc./GID
Feed fertilizer to your plants during their most active growing season.
