Gardening glossary
Deadheading
Deadheading is one of the highest-leverage 30-second tasks in the garden. Once a flower is pollinated, the plant’s default biology is to pour resources into seed production — and a plant carrying ripening seed has no reason to make more blooms. Snip the spent flower off before that signal kicks in, and the plant keeps trying.
How to deadhead:
- **Single-stem flowers (cosmos, dahlias, roses):** cut the flowering stem back to the next leaf node or lateral bud. - **Spikes (delphiniums, snapdragons, salvia):** cut the whole spike back to the basal rosette once the last floret fades. Many will produce a second flush. - **Multi-flowering stems (geraniums, petunias):** pinch out individual faded blooms at the base of the small stalk that holds them. - **Self-cleaning plants (impatiens, begonias, modern petunias):** skip deadheading — they drop spent blooms on their own.
Use clean, sharp snips or your thumbnail. Ragged tears invite disease.
Beyond more flowers, deadheading helps in three other ways. It keeps borders looking tidy. It prevents aggressive self-seeders (cosmos, calendula, forget-me-nots) from taking over next year. And it concentrates energy into the crown and roots, which is what you want heading into autumn.
When *not* to deadhead:
- Plants you want to self-seed (love-in-a-mist, poppies, columbine). - Anything grown for ornamental seed heads or hips (rose hips, echinacea cones, ornamental grasses). - Late in the season, when you want the plant to harden off and prepare for dormancy.
For annuals like petunias, marigolds, and zinnias, a weekly deadheading pass can double the length of the flowering season. I’ll flag deadheading windows for the ornamentals in your Growli garden so you do not have to track each plant separately.