Oxalis is a perennial plant.There are 900 species of oxalis–some with yellow flowers, other with purple, violet, or pink flowers. Some species are known as wood sorrels. Some are called false shamrocks.
Oxalis can reproduce by rooting stem joints, tubers, or small bulblets depending on the species.
It can take years to eradicate oxalis from a lawn or garden. All parts of the plant must be removed from the soil–even tiny parts of tubers or bulbs.
Description and Life Cycle of Oxalis
- Plant spreads on stems 2 to 12 inches; initially grows from a single taproot.
- Yellow oxalis has stems that root at the joints as the stems spread; capable of invading large areas.
- Cape oxalis has a deep taproot that produces numerous small white bulbs; each bulb can produce a new plant.
- Some species of oxalis have a tuberous root system.
- Green or purplish compound leaves consist of three heart-shaped leaflets at the end of 1 to 2 inch stalks.
- Yellow oxalis has small yellow flowers ¼ to ⅓ inch across with five petals.
- Cape oxalis has yellow funnel-shaped flowers up to 1 inch across.
- Cylindrical seed capsules; ripe capsules can burst sending seed 10 feet away
Root System: Yellow oxalis initially grows from a single taproot; new plants are created at stem joints that root. Caple oxalis has a deep taproot that produces numerous bulblets. Bulblets or portions of bulblets left in the soil will produce new plants. Some species have a tuberous root system.
- Pull of dig small plants of yellow oxalis before the flower or set seed.
- Dig out roots and root bulbs of cape oxalis.
- Any part of a root, tuber, or bulb left behind can reproduce a new plant; so control can be difficult.
- Solarization may control cape oxalis.
- Mulching the infected area with landscape fabric or cardboard topped with mulch for a full year may suppress oxalis.
Range: Oxalis can be found throughout the United States.
Scientific name: Oxalis corniculata (yellow oxalis); C. pes-caprae (cape oxalis); all species are members of the Oxalidaceae family.
Four Quick Ways to Control Weeds:
- Weed early. Control weeds in the first month after they germinate.
- Weed often. Hand weed every two weeks through the season.
- Weed by hand when the soil is wet (best to get roots).
- Use a hoe if the soil is dry. Decapitate weeds before they flower and drop seed.