Aren’t these little clovery plants growing around the fava beans sweet? Not if you know what will happen in a few weeks. By tomorrow or the next day they could be 1 to 2 feet tall. It’s commonly called Sourgrass but is officially Oxalis pes-caprae according to Sunset Western Garden, and it can be beautiful with its juicy leaves and stems and bright yellow flowers, but it is a seriously competitive plant. The yard next door is a field of light green and yellow every winter even though it is a thick tangle of dusty ivy all the rest of the year. Sunset opines that it can be a “troublesome pest in an open garden.” What an understatement. What it doesn’t kill by crowding in the winter, it smothers when it dies off in March and drapes its body over anything lower. Oxalis is an amazingly successful plant. It spreads by bulb division and seed and the bulbs can be found 3 feet under the ground. A few years ago I dug a 3 foot deep pond (Yes, it was a lot of work in my rocky and heavy clay) and I was still finding bulbs, fist sized ones, at 3 feet. Pulling up the oxalis doesn’t do much good because the stem usually breaks off underground. It comes right back, often with 3 heads instead of one, but if you pull it up over and over again it doesn’t grow so high that it kills the surrounding plants. Some gardeners think that if you can keep it from flowering, you will have fewer plants the next year. I have not seen that reduction.
10 years ago, as the woman next door was sadly getting ready to move into an assisted living apartment, and listing all the things she would miss, she suddenly brightened up and said “but, I’ll never have to pull out another oxalis plant!
I liked Sourgrass better when my kids were young. It grows wildly and rampantly in our area even through cracks in the sidewalk. Kids like picking the flower stems and chewing on the bottom to get a mouth-puckering but tasty juice. (Think sourballs) The rule about picking sourgrass was to only pick where dogs couldn’t have peed on it.