Nearly every homeowner desires an attractive lawn because this is one feature which most enhances the appearance of the average home grounds. Healthy, attractive lawns are not an accident but the result of a regularly and carefully executed maintenance program. This applies to the soil as well as to the turf grass itself.
Turf grasses will not grow well in highly acid soils like we have in NJ, and since most soils in in Monmouth, Ocean & Middlesex Counties are acid by nature, well established lawns will require applications of lime. Acid conditions of soils can be brought about by the leaching out of calcium and magnesium, the alkaline constituents, from the soil; yearly applications of nitrogenous fertilizers; the use of organic materials, such as compost or peat moss, used to condition the soil or as a top dressing; and the washing of sulfur from the air by rains into the soil.
Acid soils are commonly referred to as “sour,” whereas alkaline soils are called “sweet.” The reaction of soils is measured by the quantity of hydrogen (–H) ions in the soil which is expressed by numerical units numbered between 1 and 14, with 7 being neutral. In West Virginia, soil reactions may vary between pH 4.0 and pH 7.0. Soils with a reaction of less than pH 7.0 are acid and those with a reaction greater than pH 7.0 are alkaline. Most lawn grasses perform best at a reaction between pH 6.5 and pH 7.0.
Functions of Lime
Lime is primarily a soil amendment or conditioner and not a fertilizer, as is commonly thought. Lime performs several important functions:
1. Corrects soil acidity
2. Furnishes important plant nutrients—calcium and magnesium
3. Reduces the solubility and toxicity of certain elements in the soil such as aluminum, manganese, and iron. This toxicity could reduce plant growth under acid conditions
4. It promotes availability of major plant nutrients. Calcium acts as a regulator and aids in bringing about the desirable range of availability of many plant nutrients. Some elements which lime aids in regulating are zinc, copper, and especially phosphorus.
5. It increases bacterial activity and hence induces favorable soil structure and relationships. Soil structure is also improved by the addition of decayed organic matter or compost. The soil becomes more porous, increasing air circulation and the ability of the soil to absorb and hold moisture.
Time of Application
To obtain maximum efficiency and faster action, the best time to apply lime to the lawn is when the soil is being prepared for planting. This applies to the sub-soil as well as the topsoil because lime moves very slowly through the soil. Research has shown that it it takes up to two years for lime to move two two inches through the soil.
Applications of lime on established lawns may be made at any time of the year, the most favorable time of the year being fall, winter, or early spring, in that order. If applied when the soil is too wet, it is difficult to obtain an even distribution. If heavy equipment is needed to spread the lime, make the application on level areas when the ground is frozen. Less damage is made to the soil and grass under these conditions. Alternate freezing and thawing and early spring showers hasten its penetration into the soil.
Lime must be spread evenly over the entire area because it does not move horizontally. The use of a spreader insures a better distribution and permits the lime to be placed next to flower beds or in close proximity to acid-loving plants.
Pelleted lime is now available at most garden centers. Pelleted lime costs a little more but has several advantages in that it goes through a spreader more easily; may be spread by hand without being covered by dust; dust does not drift or blow into areas where lime is not wanted; eliminates such problems as tracking lime onto patios, etc. or into the house; and is easier to clean up if the bag is broken.
Rate of Application
It should be remembered that too much lime can be as damaging to lawn grasses as the lack of lime. Also, lime is not a cure-all to all lawn maladies but an ingredient which can correct soil acidity, thus creating favorable conditions for other factors to occur which develop favorable conditions in soil for lawn grasses. It is important that homeowners know that lime is necessary and how much is needed so that they can make the proper application for the first step toward a healthy lawn.