The best way to ward off insect and disease problems is to grow a healthy plant. Just as a wolf pack will target the weakest member of a herd, insects seem to zero in on a plant that is under stress. Good gardening practices—choosing the right plant for the spot, soil preparation, proper planting, feeding, watering, mulching, and the like, all go a long way to keep our gardens free of damaging pests.
But cultural control goes further than just having a green thumb. Sometimes our yards are invaded by insects no matter how good a gardener we are. In that case, it pays to know the enemy.