Like all fruticulose labiates which have a hard compact tissue and contain much oily matter, the lavender absorbs less moisture than herbs which are soft and spongy, and, as it always prefers a dry calcareous, even stony, soil, the northern cultivators find that by selecting such localities the tissues of the plant take up so little water that the frost does not injure them.    From Wordnik.com.  [Scientific American Supplement, No. 799, April 25, 1891] Reference