Early Spring Lawn Care

Spring is here! The days are getting warmer and longer. We look out at our lawn coming out of a long winter that has not been fed for a while. Its color is off and we think: if I hit it with lots of water, dump some fertilizer on it that will fix it. But wait… there are a few things to consider about feeding and watering your lawn before you start.

When to Fertilize

A program that applies fertilizer four times a year, using the holidays of Easter, Memorial Day, Halloween and Thanksgiving as a guide is desirable. An application of a quick release formula, where the nitrogen is quickly available to the plants, is best in the spring and slow release formulas, where the release of nitrogen is slower can be used for the rest of the applications.  It is better if the late fall application is slow release so the nutrients are released into the soil during the winter to help with lawn recovery in the spring.

What Type of Fertilizer

The ratio of nutrients on any plant food is represented by Nitrogen- Phosphorus- Potassium (N-P-K) in numbers. The numbers state the amount of each. For instance, a 10-10-10 is a balanced food with equal parts nitrogen, phosphorus and potassium. A fourth number would represent Sulfur (S).

Nitrogen promotes foliar growth and color. Phosphorus is useful in encouraging flower and root growth. Potassium in lawns enhances the plant’s ability to use nitrogen.

Lawns in southern Idaho can be fertilized by following one of two strategies: soil testing or nutrient ratios. In one, fertilizer rates for the lawn are based on a laboratory analysis of a soil sample. The other is based on the fact that lawns do best when fertilized with a fertilizer having a 3:1:2: ratio of N, P, K.  Spring applications can use a ratio where the phosphorus ratio is higher to promote root growth.                                 

Watering

Water deeply and less often to promote deep roots. Apply between 1”-1 1/2” of water weekly, depending on weather conditions, soil type, and landscape terrain (slopes, etc.). Soil should be moistened to a depth of about six inches. To test sprinkler output, place empty tuna fish cans or cat food tins along the water arc to see how long it takes your sprinkler to put down this amount of water. Output is greater the farthest point from the sprinkler head. (You can allow the cans to fill 1/4” or 1/2” and multiple accordingly.) One application a week may be all that is necessary, or you can divide the time into two or three applications per week. Also, take into consideration the areas where sprinklers overlap an area, and that sprinkler output varies. During hot weather, increase the water to 2” per week and apply more frequently if necessary. Visual clues that the lawn needs watering are when the grass begins to take on a blue-green color or has lost its spring, leaving an imprint behind when walked upon.
Aeration

Core aeration opens up avenues for water and fertilizer to reach down to the root zone, thus stimulating the activity of soil microorganisms and increasing root development. Lawns that have not been aerated before or those that get heavy foot traffic may benefit by aerating twice per year, once in the spring and again in the fall for the first two or three years, then drop back to once per year. On lawns that are regularly core aerated once per year in the spring is enough. Do not rake up plugs afterwards, these are topsoil and will decompose naturally, mow over them and they will soon disappear. An application of no more than a ¼” of compost after spring aeration is beneficial for all lawns.

Thatch

Thatch is not caused by leaving grass clippings on the lawn, as is commonly believed. It is an accumulation of dead and partly decomposed leaves, stems and roots above the soil surface but below the green leaves. Up to 1/2 inch of thatch is beneficial, acting as natural mulch, insulating the soil, reducing water evaporation and soil compaction, and increasing the lawns spring and wear tolerance.

Too much thatch serves as a barrier preventing air and moisture from moving into the root zone of the plants, causing the turf to dry out much too rapidly. This provides a haven for insects and disease. If thatch is over 1/2 inch, power raking in early spring is advised. Power raking every year is not necessary and may actually damage the lawn.

Giving your lawn an application of a slow release fertilizer in the fall will give your lawn a jump-start in the spring.