This garden term may be new to some beginners, but it represents some very important operations in our business.
In plants in pots it means with those plunged outside in summer, such as azaleas, acacias, hardy roses, etc., that an inch or less of manure and soil, or all manure, is put on the surface of the pot. Sometimes chemical fertilizers are added to the compost. Its purpose is twofold. It feeds the roots and encourages them to come to the surface, which they do, feeding on the mulch which is applied, and it prevents the hot sun from parching the soil, which necessitates such frequent watering. The good effects of an inch of cow manure applied to azaleas this past July plunged in the broad sun have been most marked. It is sometimes done inside, where plants cannot be shifted, but when the roots need more nourishment.
On plants in beds, such as roses and carnations, it is a most important operation. The soil is shallow and the application of half an inch of manure or a rich compost containing bone dust or sheep manure is the greatest help to them. And in spring the mulching on our beds has the same effect as that on the pots in summer; it prevents evaporation.
Not so much to encourage growth as to save the lives of trees and shrubs that are recently planted, mulching is of the greatest benefit to all trees and shrubs that are planted the previous fall or present spring. It has saved the lives of millions of young trees. In dry weather a freshly planted tree needs water, however scientifically you have planted it, and to water on the surface tends only to aggravate its condition, as the ground soon becomes parched. By laying two or three inches of stable litter on the surface of the ground for a distance extending farther than the roots of the tree you will prevent evaporation from the ground. It will keep the ground cool and moist, and when you do water no baking of the ground will ensue; the tree or shrub will get the benefit of the watering for many days. This mulching of newly-planted trees is of the utmost importance. Many young trees, evergreen or deciduous, shrubs and fruit trees, all alike, are saved from death by the simple and inexpensive operation of mulching.
It is also the only way we can fertilize our hardy herbaceous plants. An inch or two of manure laid between the rows in early spring prevents drying out, feeds the roots, and can, later in the fall, be lightly cultivated into the soil.