deadheadinG 103
Some years you may not need any new seedlings, in which case the plants should
be completely deadheaded. A predominately self-sown garden can be an
economical approach for the budget-conscious gardener, although it does
require intervention to keep it managed.
So, in certain instances, reseeding can actually be a reason for not deadhead-
ing, such as when it makes for a more diverse or more economical planting.
Attractive seedheads is another good reason. Many plants, such as Anemone
pulsatilla, Asclepias tuberosa, Dictamnus albus, Sedum ‘Autumn Joy’, and most of
the ornamental grasses extend their season of interest through the summer to
the fall, perhaps even into winter, with their ornamental deadheads. Care must
be taken, however, not to allow too much seed formation; even if you choose to
allow seedheads to form because they are attractive, physiological concerns for
the plant remain. The seeds are a sink for the plant’s energy and the rest of the
plant may suffer. I found this to be true with Siberian iris. I got greedy one year
and left all the deadheads on the plants until the following spring, at which time
I cut them and used them for dried arrangements. The plants were drastically
weakened, opened up in the center, and had a significant reduction in the
number of flowers produced—all the signs that division is needed. The plants
were only 2 years old, and Siberian iris usually doesn’t require frequent division,
so I figured that this condition was related to the number of seedheads allowed to
mature. Now I remove about two-thirds of the seedheads and allow a third to
mature on the plants. This doesn’t seem to drain them.
Coreopsis lanceolata requires
frequent deadheading to keep
up its appearance.(opposite) This chance seedling
of Rudbeckia fulgida var.
speciosa in the front path
of my garden is a charming and
welcome surprise.