While one main meal is all common landscape plants, trees, and lawns need for health and vigor, especially if you are working to improve the quality of your soil over time. Occasional "snacks" of fasting-acting fertilizer can boost their vigor in certain situations. Remember snacks are definitely optional. Spread granular fertilizer on the ground or either spray dilute liquid fertilizer on plant foliage or pour it into the soil when watering. Do not overdo. Excess fertilization will promote lots of foliage growth at the expense of flowers and fruit. The abundant tender new growth attracts aphids and other pests.
Spraying fast-acting liquid fertilizer on the lawn is not a substitute for a main meal. Consider it a useful supplement, especially when certain soil or weather conditions prevent the normal uptake of nutrients by plant roots. For instance, in early spring or late fall, cool soil often restricts the availability of nitrogen and phosphorus in the soil. Feeding some plants through their leaves at these times, corrects many nutrient deficiencies. Foliar feeding allows you to help meet a plant's nutrient needs without watering the root zone--an advantage during rainy seasons.
Choosing And Using A Snack Fertilizer
In choosing between liquid and dry fertilizers for use as snacks, bear in mind that plants absorb nutrients 20 to 30 times faster from liquid types than from dry products. Also, when the nutrients are sprayed directly on plant foliage, it absorbs the spray into its cells, receiving 100 percent of the nutrient value of the fertilizer.
To avoid over-fertilizing, make the liquid very dilute (less than half the concentration prescribed on the bottle). In most cases, a dilution of 1 tablespoon of any kind of liquid fertilizer to 1 gallon of water is safe and effective. At that dilution snacks every month, or as frequently as every 2 weeks, do not harm plants. Over time, liquid fertilizer costs a bit more than granular types given as snacks.
When giving snacks to plants with granular fertilizer, spread it lightly around the base of each plant for the rain or watering to soak in. Do not let it touch the leaves and stems, lest it burn them.
Snacks for Lawns and Other Landscape Plants
For residential landscape plants a monthly snack (May, June, July, and August) is sufficient to improve their general condition and help them meet the stress of heat and drought. To boost performance of certain flower and vegetable plants that produce all season a bi-weekly snack is even better. Remember, these snacks are optional and homeowners with truly low maintenance landscapes do not bother with them at all.
Liquid Snacks - Provide liquid snacks by foliar spray in the early morning of a cloudy, humid day. Spraying in the evening leaves plants wet overnight, which could create disease problems. Set your sprayer nozzle to the finest spray possible. Before any spraying, make sure the plants are not suffering from lack of water; dry plants absorb the foliar spray too quickly, burning the leaves. Completely soak plant foliage to the point where the leaves are dripping. Make sure to wet both upper and lower leaf surfaces.
Dry Snacks - Dry fertilizer snacks can be served as "side-dressings". Use very little, less than half the amount recommended per square foot on the container, working it lightly into the soil around the plant. Keep the fertilizer at least two inches away from the trunks or stems of the plants. Be careful not to use too much.