Picking Pickerelweed
Picking Pickerelweed
Puddock Hill Journal #45: This spring’s introduction of pickerelweed to the big pond seems off to a good start.
Friends recently visited and remarked that our ponds are remarkably free of algae and watermeal. Indeed, back when we used to have a pond in Bedford Hills, NY, near where these folks live, on a calm summertime day it looked like a putting green. I’ve learned a thing or two since then.
With all due respect to our friends, the big pond at Puddock Hill in fact is not entirely free of anything we would consider an invasive or a nuisance. There is some watermeal, and I’m constantly battling efforts by Eurasian watermilfoil to block the spillway (by this time of year, always losing that battle). These things in moderation are not catastrophic, however, and some degree of algae should be present in any healthy aquatic system.
Yet, it’s true that our big pond has a relative paucity of green floating and emergent things. (Watermilfoil does grow in profusion in the small pond, but it has little algae and no watermeal—I think because it’s mostly in shade.)
I explained to our friends what we do to keep the pond in balance:
With a permit from the state, we introduced triploid carp to eat emergent plants.
We deploy a bacterial product that consumes excess nutrients in the water.
We built a spillway to skim off floating material, and I make great efforts to keep it clear.
We let vegetation grow on the edges to disrupt surface flow of nitrogen runoff into the pond.
Yet, by this time of year, the shallow end of the pond (as shallow as 6-12 inches by the shore) does go green with algae and is often choked with watermeal. It doesn’t help that prevailing winds blow much floating material toward that end. (Pro tip: If you have the opportunity to build a spillway anywhere on your pond, put it on the eastern side so the prevailing wind can assist you.)
In an effort to address this piece of the pond puzzle, we decided to introduce pickerelweed (Pontederia cordata) to the pond shallows this spring. With a range up and down the East Coast and as far west as Illinois, Minnesota and Texas, this successful native grows in standing water and can bloom all summer long. Waterfowl eat its seeds, it attracts dragonflies, and its flowers provide nectar for bees and butterflies.
Humans can also eat most of the plant. As reported by the Lady Bird Johnson Wildflower Center: “Pickerelweed has often been used for food. Each fruit contains a nutritious, starchy seed that can be eaten straight from the plant or dried and added to granola and other cereals. The dried seeds can also be boiled, roasted to improve flavor or ground into flour. The young leaves have sometimes been eaten raw in salads or boiled and served with butter.”
I confess to never having done any of this, but on field trips in graduate school the plant’s beauty and abundance charmed me. So does the prospect of having it compete with invasive and nuisance plants and enhance the natural ecosystem of our pond.
Pickerelweed consumes a great deal of phosphorus and nitrogen, so I hope ours will help naturally remove these nutrients that are often overabundant in ponds. Furthermore, if it spreads as I hope it will, the plant will shade out lower-growing competition, cool the water with that same shade, provide hiding places for frogs, turtles and fish (its name, of course, suggests association with pickerel), and feed wildlife as noted above.
We bought a hundred plugs and pressed them into the muck at the pond edge in five places. “Don’t expect any flowers this year,” I told my wife. In fact, for the first few weeks they looked remarkably sad and vulnerable, their young droopy leaves floating forlornly on the water’s surface. But I proved to be wrong about the flowers. Two months later the plants have become erect, grown to full size, and established themselves with great vigor, even managing to flower:
They seem happy in all five places we planted them, and my hope is that they will naturalize through the shallows, increasingly supporting wildlife and providing the other benefits I’d like to get from them. I have little fear they’ll take over the entire pond, since they won’t grow in water deeper than 12-18 inches.
So far, our pickerelweed introduction looks like a huge success, and I can’t wait to see what next year brings. Plus, I now have a fifth natural pond-health strategy to add to my list!
The delicate flowers of native agrimony (Agrimonia spp.) bloom by the big pond:
Joe Pye weed (Eutrochium purpureum) makes a good show in the barn meadow:
A native Eastern tiger swallowtail (Papilio glaucus) feeds on native common milkweed (Asclepias syriaca) by the big pond embankment:
Flowers of native Carolina horsenettle (Solanum carolinense) have been abundant this summer:
Canada goldenrod (Solidago canadensis) blooms beside the big pond (algae behind it!):
