Are expensive soil probes really necessary?
Soil probes are devices used to obtain core samples from the soil. They measure the depth at which the soil turns from moist to dry. Deeply rooted trees do best with deep but infrequent watering. Annuals and perennials with the roots closer to the surface do better with more even watering. In addition, some spots in the garden drain faster or slower than others. A soil probe can tract these things and tell the gardener where there is too much or too little water throughout the garden. Soil probes are usually tough, life-time tools but they are also rather pricey. They may not be totally necessary but generally speaking, they are probably worth every penny. Its hard to give really good tree care without a soil probe. Peaceful Valley Farm Supply has a quality “18 inch soil sampler” that sells for about $35 (U.S.). Their address is P.O. Box 2209, Grass Valley, Ca., 95945 or http://www.groworganic.
