A gardener's summer is filled with deadheading. In my case, I'm consumed by it, a daily activity, the act of keeping things tidy. As much as anyone understands deadheading, the principle is simple; to remove a finished flower or seed pod to encourage energy to flow back into the plant, hastening new growth. As simple as it sounds, it's a bit complex. Annuals and perennials are the primary subjects of deadheading, although shrubs like butterfly bush and roses are freer flowering if spent blooms are removed.

Annuals, true annuals such as sunflowers, zinnias, and marigolds may be left to seed, the latter volunteers generally inferior to the parent plant, which are the result of careful breeding. Most of the time sunflowers are grown for the birds, the seeds allowed to ripen fully with a smattering of seedlings returning; the birds never seem to consume them all. Zinnias rarely seed for me, but I am judicious at cutting them for flower arrangements, a form of deadheading and encouraging more flowers. Marigolds do respond to regular cleaning or removal of spent flowers, it does encourage more, this the gardener learns from doing.

Perennials often require a little homework, only because there are vastly different plants lumped together into one category. Those with umbelled flowers such as fennel or parthenium are shortlived or biennial. With the aim of absolute seed removal, you've closed the door to future generations because this year's flowers may be the last the plant will produce. Other short-lived perennials include columbine, Linum, gaillardia, and campion, all of which require a bit of seeding to return.

Big flowering bulbs like lilies are better with deadheading, but only high on the plant, allowing foliage to cure or restore the bulb to a healthy state for next year. Daylilies are deadheaded every day and routinely cut to the ground as the show ends. Since they are not bulbs, there is no harm in the removal of foliage and it sets them up for a surge of new leaves that remain handsome into fall.

Phlox and bee balm are not only deadheaded but also cut to the ground (6" or less). The resurgence of new growth is most welcome and richly green. Coneflower poses a bit of a conundrum, the fancy hybrids will seed and the subsequent seedlings will be inferior to the expensive plant you purchased. The majority of seedlings will grow into thigh-high purple daisies, which is certainly fine, but you may have been better off just buying Echinacea purpurea, or E. laevigata and allowing them to spread at will. With the fancy ones, I do deadhead, with their expensive price tag; I aim to keep them true. One exception is a seed strain named E. 'Cheyenne Spirit', the idea was to allow them to volunteer, which they will do in a wonderful array of colors.

Sometimes the seeds are too pretty to remove. My first thought goes to the ornamental onions, so handsome are the seed heads that garden art has been created to imitate them. Other plants with glorious seed heads are nigella or love in a mist (annual), ornamental grasses, milkweed (my humble opinion), and most poppies. Leaving them is a decision best made with some knowledge of how much and how far they will spread. As I said, it's complex.