Definition of undergrowth for Students. : low growth on the floor of a forest that includes shrubs, herbs, and saplings.
From Organic Gardening Magazine, July/August 2000 Issue. Miracle-Gro is a synthetic fertilizer that contains ammonium phosphate and several other chemicals that can be toxic to your soil and plants. It is prohibited from use in certified-organic farming.
Soil fertility authority Garn Wallace, Ph.D., of Wallace Laboratories in El Segundo, California, points out that Miracle-Gro contains muriate of potash, which contains excess chlorine that will burn plants and inhibit the uptake of nitrogen.