How to Grow Oxalis? A Detailed Guide to the Latest Cultivation Methods
Oxalis is also known as sour grass, spotted dove sorrel, three-leaf sorrel, etc. It is a perennial herbaceous plant of the genus Oxalis in the family Oxalidaceae, blooming continuously through spring, summer and autumn, with the most abundant blooms during the cool periods of spring and autumn. Because of its low stature, fast growth and long flowering period, it puts on a spectacular display when in bloom, and it is widely used in landscaping. Now let us take a look at how to grow oxalis!
Growth Habits of Oxalis
Oxalis grows on hillside grassy patches, along river valleys, roadsides, field edges, wasteland or in shady, damp places under trees. It prefers sunny, warm and humid environments. In hot summer regions it is best given half shade. It has fairly strong drought resistance but is not cold-tolerant. In North China it must be grown in a greenhouse in winter; south of the Yangtze River it can overwinter outdoors. It likes shady, damp environments and has strong adaptability to soil. Ordinary garden soil will support its growth, but it grows most vigorously in sandy loam rich in humus. It has a short dormant period in summer. It opens its flowers when the sunlight is extremely bright.
Propagation Methods for Oxalis
1. Division: First select a plant with good growth, that is, one whose rhizome has many small branches, and take it out of the pot without removing the soil from the roots. Use your hands to break the plant into several clumps; the size of each clump is determined by the buds on the rhizome, and usually each clump keeps more than 3 buds. If there are many leaves, they can simply be removed. After drying the wounds in a shady place, put the divided plants into sandy soil and keep the temperature at 13-18 degrees C; they will soon take root and grow leaves.
2. Sowing: Oxalis seeds are quite small, so they should be sown indoors in pots. First prepare a flower pot with a slightly larger diameter (a foam box can be used instead), scatter the seeds evenly on the soil surface, and cover with 1-2 cm of soil. After sowing, cover with a layer of plastic film to maintain humidity in the pot. They will germinate 10-12 days after sowing. Once small seedlings have grown, they can be transplanted into flower pots, with 3-5 plants per pot.
Cultivation Methods for Oxalis
1. Soil: Oxalis has strong adaptability to soil, and ordinary garden soil will support its growth, but it grows most vigorously in sandy loam rich in humus. Because oxalis grows very fast, the pot should be repotted once every spring. When repotting, it is best to change the soil, preferably a loose, fertile, slightly acidic soil with good drainage.
2. Temperature: Oxalis likes a warm environment, and its most suitable growth temperature is 16-22 degrees C. It is not cold-tolerant; below 10 degrees C the plant stops growing, and at 0 degrees C the leaves wither. However, as long as the underground rhizome is not frozen, it can still sprout new leaves in April of the following year and grow normally. To keep the leaves in normal condition in winter, the temperature should be kept above 5 degrees C. It is not heat-tolerant; when the temperature exceeds 35 degrees C, the leaves curl, growth slows, and it enters a dormant period.
3. Light: Oxalis needs sufficient light to grow and should be grown in full sun or partial sun. In spring and autumn it should receive plenty of sunlight; too much shade will make the leaves dull and lusterless, while the leaf stalks become weak and the plant shape becomes straggly. But strong direct light should also be avoided; from May to September it should be shaded appropriately to prevent sunscald. It has a strong tendency to lean toward light, so when keeping it on a balcony or windowsill, the position of the plant should be changed frequently so that all sides receive light evenly.
4. Watering: Oxalis is drought-tolerant but likes a humid environment. During the growing period, keep the potting soil moist, following the principle of “do not water until dry, and water thoroughly when you do”. In the hot summer season, the plant enters a dormant period, and at this time it should be misted, keeping the potting soil only slightly moist. In winter, when the temperature drops below 10 degrees C, water sparingly rather than generously to prevent the bulbs from rotting.
5. Fertilizing: When potting oxalis, apply sufficient base fertilizer. During the growing season, to keep the plant growing robustly and ensure thick, glossy leaves, apply a nitrogen-phosphorus-potassium compound fertilizer once a month. Pay attention to the concentration when fertilizing; too high a concentration will burn the bulbs and affect growth. Stop fertilizing from July to August. Be careful not to apply a single nutrient, especially nitrogen fertilizer, as it will turn the leaves from purple back to green and reduce their ornamental value. When fertilizing, do not splash the liquid fertilizer onto the leaf surface, as it easily causes leaf diseases.
6. Pruning: When oxalis plants grow too vigorously, promptly remove the denser leaves to improve ventilation and light penetration and promote growth. In daily care, promptly remove withered and yellowed leaves to reduce the occurrence of pests and diseases. If the leaf stalks are too long or the plant shape is unattractive, the leaves can be heavily pruned to let new leaves grow again.
7. Pests and Diseases: Oxalis grows densely, and the lower part has poor ventilation and light penetration. High temperature and humidity make it prone to powdery mildew, with leaves turning yellow and becoming moldy and rotten; fungicides such as triadimefon and thiophanate can be sprayed. In addition, spider mites begin to cause damage in early May. Because oxalis leaves are dense, control is difficult, so prevention must be the main approach. Start spraying acaricides when the temperature rises in April; do not wait until spider mites break out in large numbers before treating them.