The Oxalis rubra, or commonly called wood sorrel, is a perennial herbaceous plant native to South America. The oxalide is a tuberous plant, which tends to become carpet if the climatic conditions allow it to flourish; the Oxalis rubra forms large roundish cushions made of small trilobate leaves, very similar to the trefoil; from spring to autumn it produces numerous small bell-shaped flowers, gathered in bunches, of a flying or red color, with dark veins. Very suitable for rock gardens and as a border in flower beds. The O. montana variety has white veined pink flowers.
It is also used as an aromatic plant and in the past it was used to remove ink from fabrics; its particular taste, reminiscent of lemon, makes it used in many dishes.
The sorrel needs sunny positions, especially in spring when the direct sunlight is not too strong; if the summers are particularly hot it is advisable to place it in a semi-shaded position; generally it does not suffer much from the cold, since despite being an evergreen plant, in places with cold winters, the dry aerial part and the tuber goes into vegetative rest, thus bearing a few degrees below zero.
In areas where temperatures are particularly low, it is however advisable to mulch the soil above the tubers, or it is advisable to dig them up and keep them in a dry and cool place (even if you want in the fridge) to put them at home at the beginning of the following spring.
From March to October water the Oxalis rubra plants regularly, without exceeding; in July-August it may be necessary to water the oxalide often, while for the remaining months a weekly watering may be sufficient.
Water deficiencies cause a prostrate posture of sorrel leaves, which is completely resolved by watering the plant; it easily supports short periods of drought. Always check that the soil is not soaked and that there are water stagnations that do not benefit the sorrel plants.
From November to February the plant is in vegetative rest, so it does not need watering, which could cause the tuber to rot. In the vegetative period provide some fertilizer for bulbous plants every 15-20 days.
The sorrel prefers rich, loose, very well drained soils; you can use a good universal soil, mixed with a little manure, sand and perlite to prepare the ideal substrate for its cultivation. Check that the soil in which the Oxalis rubra is planted does not allow the formation of water stagnation.
the tubers produce numerous side shoots, which can be detached at the beginning of spring, using a well sharpened knife; the new tubers thus obtained must immediately be planted. It is also possible to sow the oxalis, using the seeds of the previous year in spring.
Acetosella, Oxalide - Oxalis rubra: Parasites and diseases
Oxalide plants can be affected by powdery mildew and rust which can seriously damage their leaves. If the presence of oidium is noticeable, it is advisable to intervene with specific sulfur-based products that are sprinkled on the affected plants. In this case, be careful not to consume the leaves.