Seed capital

One gardener’s spectabilis is another’s horribilis. When flowering plants make viable seeds that spread around the garden to germinate next year, you may think it’s a blessing or a curse.

            Remember that primary school unit about how seeds travel? I have examples of all the strategies in my garden this month, from burrs to wind-catching silky parachutes to fruits that co-opt birds to carry the seed to new locations. We plant for flowers, but the plants’ goal is to pass on their genes to another generation.

            Usually I like having the surprise of little seedlings popping up here and there in spring. This is the time of year when I have to decide who shall live and who shall die (or at least reproduce)--which seedheads to leave alone and which to clip out before they can drop their seeds.

            Some of my favorite purchases have turned out to be self-seeders, especially white bleeding heart (Dicentra spectabilis ‘Alba’). Spectabilis translates as “worth looking at,” and that perfectly describes the glowing heart-shaped flowers when they bloom in my May garden. 

White bleeding heart--worth looking at

Other enthusiastic self-seeders I enjoy include columbine (various species of Aquilegia), dwarf goatsbeard (Aruncus aethusifolius), and forget-me-not (several species of Myosotis). When these sprout in unexpected locations, I let some grow, pull some out, move others to better spots, and pot a few to give away.   

Columbines sometimes cross-breed, changing flower colors in the offspring, but this dark purple has stayed true.

             Then there’s tall verbena, Verbena bonariensis, whose seedlings are legion in my vegetable beds. This odd South American self-seeder sends up a single 3- to 4-foot stem with a small lilac purple compound flower at the top. It’s a prolific producer of seeds considered invasive in the South, but not in Massachusetts yet. I bought some from a mail order nursery ten years ago, and new volunteers sprout every year.

            I keep some of the seedlings because migrating monarch butterflies used to touch down on the flowers to refuel. I haven’t seen the monarchs for a couple of years, perhaps because their population has declined drastically due to habitat loss and the use of herbicides that eradicate the milkweed their caterpillars need for food. 

Instead of monarchs, nonnative cabbage white butterflies (Pieris rapae) are visiting the tall verbena this year.

I’m growing some milkweed now in hopes the monarchs will return.

Seeds of swamp milkweed (Asclepias incarnata) getting ready to float on silky floss

            Because I patrol the beds each growing season deciding which seedlings to coddle, which to tear out and which to relocate, I maintain something close to the balance I prefer. Like ground covers that can spread unmanageably, self-seeders can be so effective that they take over the garden. At least with the self-seeders, I can say no to future spread with diligent dead-heading in late summer and fall, removing spent flowers before they set seed.