My neighbor has three majestic Siberian elm trees on the other side of his field that invade my yard every April with seeds like aliens invade New York. One reason the seeds make me think of an alien invasion is their shape. They are thin disks, with a tiny bulge in the middle where the actual seed goes for it’s ride across the Universe of Horse Pasture. The disks, a dirty white color and about half an inch in diameter, seem to be made of paper, but are very durable. (click on any photo to enlarge)
They may be tiny alien spacecraft, but they take full advantage of the sheer power of numbers. They cover some areas like a paper carpet. They hide in nooks and crannies, including all my seedings in pots hardening off on the patio. They nestle under all my vegetable and flowers in the yard. And that is why when I see those paper saucers floating through the air in their initial attack, I pull on my hair with both my hands and wail like a mad woman.
My children say soothing things, like, “It’s okay, Mom. We survive every year.” And I mumble something back while I rock from side to side for a few minutes. Then, I get busy taking measures to limit the damage. This includes handpicking clumps of seeds from my garden beds.
Just about 2-3 weeks later, they begin sprouting. It depends on how moist and warm the spring has been. But whenever they sprout, they will sprout Everywhere. Since I know what they look like when they are first ejected from their protective capsules, I can get to many of them when they are still vulnerable and easy to pull.
There are always some seedling that I don’t find until they are bigger. This is a problem because within a few short weeks, they will develop a root with the tenacity of reinforced steel. Within a year, they will often be three feet tall and have a 3/4 inch trunk diameter. Digging them out requires super human strength in all but the loosest soil. If any have grown up close to a desirable plant, it can be very difficult to remove them without harming that plant.
I have other mature trees in my own yard that spread seed of various sorts. The helicopters of maple trees are prolific. The squirrels bury an apocalyptic supply of acorns and walnuts. There are even some seedlings of Russian olive trees from nearby wild groves. But none of these seeds have the same combination of sheer numbers and gripping, long roots of elm tree seedlings.