October 4, 2007
A RIDDLE. If it takes duckweed 30 days to cover a pond, how much of it is covered on day 29? Half, I was told: it
doubles overnight. I don’t quite believe that, but it is a prodigious grower: one week scattered green spots; the next a lawn on your water. I used to think it pernicious and attacked it with herbicides. Now I consider blanket weed far worse, and try to love the world’s smallest plants as they proliferate.
The arguments against them are obvious.
They hide the surface, abolish reflections,
darken the depths and cling to anything
that touches them. The arguments in
favour? They feed on nutrients in the water that cause other problems. Removing them is a way of cleaning the whole pond. On a small one it is not such a bad job, skimming off the mass of tiny leaves. You wait for a windy day to push them to one side of the pond, then drag them to the edge with an improvised broom, or fish them out with a paddle-shaped net. Each leaf is a plant trailing a tiny white root. They reproduce by
growing little buds that split off and grow on.
Once you focus on the tiny things you can even find beauty in them. Skimming them you encounter a world of bugs, beetles, tiny snails and tadpoles. You can polish your water surface clean and
gleaming, or tolerate a few green rafts. When your weeding is finished, everything is pruned, the car washed, potting shed tidied, and you’ve swept behind the dustbins, amuse yourself by watching them grow.