Annual Oxalis Flowers

Care

• Oxalis prefer moist, well-drained soil and full sun or part shade. They like a lot of water, and will wilt if the soil dries out. Depending on the species, they can be grown outdoors in USDA hardiness zones 6 through 10, or indoors in pots. If kept indoors, place them in an east or west window, avoid cold or hot drafts and fertilize them every two to four weeks. Oxalis plants like daytime temperatures of 60 to 70 degrees Fahrenheit. If your plant starts to grow spindly, it could be a sign that it's too warm, or that it needs more light. A yellowing plant means that you're giving it too much water.

Diseases

• Rust is a fungal disease that is spread by spores. The fungus grows on the leaves and stems. Symptoms include yellow patches on the leaves with orange blisters appearing on the bottom of the leaves. If the infestation is serious, the plant may lose all its leaves and die. Infected leaves can be removed by hand. Clean up any fallen leaves so the disease doesn't spread to new plants in the spring. A fungicide can be used on the plant and surrounding soil. If your oxalis is potted, remove it from its pot and wash it with neem oil. Repot in a clean pot. Another disease that attacks oxalis plants is chlorotic ring spot, which is a virus spread by aphids. Symptoms include yellow ringspots on the leaves. The ringspots fade into yellow blotches and streaks as the disease spreads, and plants usually die within two years. There is no cure.

Pests

• Spider mites are tiny creatures that live on the undersides of leaves and in stem joints. They destroy oxalis plants by sucking the juices out of the leaves. They're so small that they're hard to see, but you can tell if your plant is infested by placing a piece of paper under it and gently shaking the leaves. The mites will appear as specks on the paper. Control mites by applying a miticide, or washing the plant with insecticidal soap.

Uses

• Some annual oxalis plants are edible. Oxalis Tuberosa tubers are grown as food in parts of the Andes Mountains, and the leaves, flowers and immature seed pods of common wood sorrel (oxalis montana) are edible and have a sour lemon-like flavor. Wood sorrel leaves are used in salads, soups and sauces, or made into a tea, and the plant is used medicinally as a diuretic or to relieve indigestion. However, in large amounts, this flour is toxic; people with kidney disease, rheumatoid arthritis or gout shouldn't use this plant because it contains high levels of potassium oxalate and oxalic acid. An orange to yellow dye can also be made from oxalis.