Spotted Spurge (Euphorbia (=Chamaesyce) maculata) is a garden weed that can seem impossible to control. It grows rapidly and starts producing seeds at a very small size. A large plant can produce thousands of seeds. If you pull the weed and leave it lying in the garden, many of the seeds left on the plant will be jumping off to your garden soil before you gather it up for disposal. Spurge seeds will likely emerge from the compost bin still viable, and most gardening sites recommend you exclude all weed seeds from composting.
Spotted Spurge usually, but not always, has a red or maroon colored spot in the middle of its small oval leaves. The reddish stems contain a milky juice that can cause irritation to skin and eyes upon contact. It grows like a mat, close to the ground which can reach 3 feet across. Aside from growing on any spot of bare soil no matter how poor, it is just as happy to take up residence in a crack in your sidewalk, Seeds form in a tiny triangular pod containing 3 seeds. You may not be able to see these without magnification. The plant can be found in our area from February through September, and seeds begin germination with temperatures reach 60 degrees.
The best way to outmaneuver spotted spurge is to pull it by hand when it is small or use a thick mulch, to prevent or discourage its germination. There are commercial sprays that will kill the plant, but the plant will still need to be hand-pulled, wearing gloves, to keep those remaining seeds from being left in the plant’s footprint. For the driveway or sidewalks, this is one application where a flame weeder /garden torch could be considered.
■ For more gardening advice or topics from the Colusa County Master Gardeners, visit http://cecolusa.ucanr.edu