Every time you take an aspirin, think willow, the precursor of this all-purpose pain-reliever. (Herbalists recommend white willow bark for headache, fever, and arthritis.) But you should also think willow when you want to root cuttings of your favorite shrubs and perennials, for the plant has chemical properties that encourage sprouting. To make this all-natural rooting stimulant, snip pencil-thin twigs into 1" lengths. Put two cups of the twigs into a half-gallon jar, fill with boiling water, steep overnight, and strain. To give cuttings the "root" idea, soak the lower stems overnight in the willow tea, then pot as usual. The tea you don't use will keep for a month or two.