This term generally applies to seedlings or young plants. Plants become “leggy” due to insufficient light, either from being started indoors where there is no supplemental light or by being planted too close together and competing for limited available light. Seedlings deprived of sufficient light will grow tall and spindly as they seek light. This causes weak stems and less robust transplants.
To avoid legginess, it’s important to provide seedlings sown indoors with supplemental light. Sometimes a bright windowsill is enough, but we recommend suspending full spectrum fluourescent tubes just above the seedling tray, and keeping it lit for 8 to 10 hours a day. This will result in bushier, more compact and robust growth.