Soil temperature and citrus: Low soil temperature contributes to low number of roots under citrus trees in some areas of southern California

Abstract

Low soil temperatures—causing low root temperatures—induced foliage wilt in glasshouse experiments with several citrus species on various rootstocks. At soil temperatures ranging from 48F to 62F and with plenty of moisture available, the foliage—especially succulent new growth—wilted, but plants having heat supplied to the roots did not wilt.