To keep gardens tidy and flower-filled, devote time weekly to cutting off spent blooms. Left on, they signal the plant to set seed and either die or go dormant. Removed, they encourage perennials and annuals to produce more flowers. With some plants like roses, the faded flowers are trimmed one at a time. Other plants, like osteospermum, coreopsis and lavender, get “a haircut,” a snip across the top and sides with hedge shears. Generally these deadheading cuts aren’t as deep as pruning, but in all cases, they avoid cutting into woody stems.