How Do I Get Rid Of Oxalis Pes-Caprae?

Is Oxalis Pes-Caprae Edible?

Oxalis Pes-Caprae is very low in oxalic acid and so safe to eat. Peeling is recommended. Although the plant may be slightly bitter when raw, it has a slightly sweet flavor when cooked. In South Africa it is a traditional ingredient in dishes such as waterblommetjiebredie (‘water flower stew’).

Oxalis Pes-Caprae is a reasonably common vegetable in some South African restaurants. In Colorado, Oxalis Pes-Caprae is used as the alternative to chard in salads. Some edible parts of the plant are high in oxalic acid and may cause painful irritation of the mouth if eaten raw.

This condition, known as oxalate poisoning, can be fatal to domestic animals. The plant has been used as a diuretic in South Africa, although this usage should not be attempted; please consult a veterinarian.

The flowers are edible. The leaves or roots are rarely consumed (in South Africa at least) except when starving children cut off large sections of Oxalis pea to eat or chew on them.

Is Oxalis Pes-Caprae invasive?

Oxalis Pes-Caprae is an invasive species that has spread across many parts of the world and is particularly invasive in Spain, Portugal, France, Italy, Algeria and Portugal. In these countries it can cover large areas of soil and rhizomes are often left buried into the ground.

Pes-Caprae spreads primarily through its underground bulbils. Even after digging up and destroying the bulbs, some may be left behind. The bulbils germinate and spread in a similar way to that of field mustard, but slower.

Growth is typically found in disturbed habitats such as vacant lots and overgrazed pastures. In some countries (e.g., Australia) the plant has been declared a weed and can be seized by local authorities even if you are holding it for legitimate use.

Is Oxalis Pes-Caprae poisonous?

Oxalis Pes-Caprae leaves is toxic because of high oxalic acid content. The lethal dose of oxalic acid for horses is 25 mg per kg body weight, and between 15 and 20 mg/kg for sheep. In South Africa the leaves are used as fodder for cattle, pigs and goats, usually after boiling them to remove their toxicity.

Soil in which the plant has grown is generally contaminated with many small bulbs. The tilled-in soil can be treated with the vinegar solution (5 parts water and one part vinegar), since oxalis is very susceptible to the acetic acid. This is especially true if the soil contains a high percentage of organic matter. The soil must then be completely replaced for better results.

Some herbarium specimens are reported by scientists to have toxic properties, although it is far from clear what has caused this and what effect it may have on people or animals. Conclusions in this regard should always be cautious.

How do I get rid of Oxalis Pes-Caprae?

Oxalis Pes-Caprae is very difficult to get rid of, but there are a few strategies. Similar techniques can be used to kill other weeds with oxalates, such as wood sorrel or smartweed.

Pes-Caprae seedlings can be removed with a hoe or hand weeding; this is time consuming on a large scale. Manual removal of the bulbils is also effective.

It is best to remove the bulbils when they are young and soft, before they have had a chance to develop their own roots or become embedded in soil. As with many other plants, the bulbils should be removed as soon as they are found.

The primary means of preventing Pes-Caprae from spreading is careful control of its growth in spaces between pavement cracks and other crevices where it can survive for many years as a dormant bulblet.

How do you eat an Oxalis Pes-Caprae?

Oxalis Pes-Caprae leaves is edible, but the flowers are very low in oxalic acid and so safe to eat. Peeling is recommended. Although the plant may be slightly bitter when raw, it has a slightly sweet flavor when cooked. In South Africa it is a traditional ingredient in dishes such as waterblommetjiebredie (‘water flower stew’).

Oxalis Pes-Caprae is a reasonably common vegetable in some South African restaurants. In Colorado, Oxalis Pes-Caprae is used as the alternative to chard in salads. Some edible parts of the plant are high in oxalic acid and may cause painful irritation of the mouth if eaten raw.

This condition, known as oxalate poisoning, can be fatal to domestic animals. The plant has been used as a diuretic in South Africa, although this usage should not be attempted; please consult a veterinarian.

How do you identify Oxalis Pes-Caprae?

Oxalis Pes-Caprae is easy to identify; it has a characteristic “heart shaped” leaf with a sharp point at the tip, although the existence of an undulate margin is sometimes reported. There are several varieties in common use, including the variety “compactae”.

The flowers are pink, and are produced in clusters up to 7 cm long. This form, “capriformis”, will sometimes be seen, often in cultivation.

The plant has a rosette of leaves, which are heart shaped, very sharp-pointed and undulate along their margins. Length: 5–25 mm; Width: 5–15 mm; Leaves: Rosette, basal leaves short-stalked, undulate (heart-shaped), pointed and sharp to the touch, often with a few teeth on the margins.

Leaves are arranged in a single spiral around the stem, forming an overlapping coil. Leaf tips are sharp but not blunt. Rachis between leaves is dark green; rosette leaves are dark green, often blushed red or purple in full sun.

Flowers are pink, produced in small clusters of 2–6 on short stalks from the leaf rosette. Plant grows erect by means of a stalk that originates from the center of the rosette. Flowers are clustered in dense terminal and axillary clusters, usually 7-10 flowers per cluster. Flowering lasts from September to November, depending on location. The plant sprouts new shoots and leaves in early spring.

What kills Oxalis Pes-Caprae?

Oxalis Pes-Caprae is generally well-tolerated by herbicides. The best time to spray is early in the year when it is still relatively small, before it has had a chance to spread. This also stops the development of bulbils (bulblet) in the soil.

A strong vinegar solution (5 parts water and 1 part vinegar) sprayed on the leaves will provide relief in a matter of days.

There are also many organic means of killing this plant. Tilling and digging up the roots kills off the plant, although bulbils (bulblet) will remain in the soil for many years. These bulbils grow into new plants and must be dug out individually with a small shovel.

The garden bed must be replanted with new soil, as any remaining bulbils will survive on bits of old root below ground level. Concentrated vinegar, applied as a spray onto the leaves and roots, followed by an application of lime (or preferably wood ash, which is not so alkaline) will kill the plant. But even with both of these, bulbils may remain in the soil for many years.

Although Oxalis Pes-Caprae is relatively easy to get rid of using organic means, it can take many years and cannot really be considered a ‘weed’. It is best to learn to live with it and enjoy its flowers while they last.

How do you care for Oxalis Pes-Caprae?

Oxalis Pes-Caprae is a very low-maintenance plant. It typically grows in areas of high sunlight and good soil, although it is often seen in areas with difficult conditions. The plant will die with the first frost, but will reemerge from its bulbils in the spring.

Oxalis Pes-Caprae prefers a well-drained soil, and performs best when planted close to the surface of the soil, although it can tolerate deeper planting (up to 15 cm). The following are factors to consider when caring Oxalis Pes-Caprae;

Sunlight

Oxalis Pes-Caprae is a shade-loving plant, growing in full sun or partial shade. Oxalis Pes-Caprae can withstand light frosts if planted in a sheltered position high in the garden, with southern or western exposure.

Soil

Oxalis Pes-Caprae prefers at least moderately fertile soil; it flourishes in heavier soils and prefers a moist but well-drained soil. A heavy clay soil is unsuitable for the plant, as it has a tendency to cause root rot.

Oxalis Pes-Caprae tolerates alkaline soils that are less than 6.0 on the pH scale, but requires well drained soils that do not become excessively wet during the rainy seasons. Oxalis Pes-Caprae prefers a slightly alkaline soil with a pH between 7 and 8.8, although it can tolerate slightly more acidic soil, up to around 7.6 on the pH scale.

Watering

Oxalis Pes-Caprae grows in full sun or partial shade. The soil needs to be well drained, but not excessively dry or wet, and be kept moist until roots have established and begun to grow. A good general rule is that the plant should be watered daily, unless it is in a very sunny position where water runs off quickly through the soil. The roots of oxalis Pes-Caprae are not deep, so water must be applied carefully to prevent root rot.

Temperature

Oxalis Pes-Caprae will tolerate a wide variety of temperatures, from -5oC to 40oC. Oxalis Pes-Caprae can tolerate temperatures up to about 15oC at ground level, and the plant should not be exposed to the sun (especially in cold winter climates). Otherwise it is normally grown in a sheltered position, usually against a wall or in an area protected by trees and bushes.

Humidity

Oxalis Pes-Caprae tolerates a wide range of humidity, varying from 50% to 70%; a good rule of thumb is to water Oxalis Pes-Caprae when the surface dries out. Do not water Oxalis Pes-Caprae after the middle of the day, but only when it has been exposed to sunlight.

Repotting

Repot Oxalis Pes-Caprae every 1 to 2 years, depending on the size of the plants.  Do not repot Oxalis Pes-Caprae during the rainy season when roots are still growing (following rainfall), nor after a heavy frost, as any root rot that may have occurred will make recovery even more difficult. Make sure that new roots are well established before repotting.

Propagation

Oxalis Pes-Caprae can be propagated by seed, seedlings, bulbils or cuttings. Oxalis Pes-Caprae must be kept moist until the root system has properly established itself, although watering after this point is not necessary. Bulbils (small bulb-like structures that grow at the end of each stem) are sometimes produced above ground level; these are an easy way to propagate new plants from existing ones.

Pruning

Oxalis Pes-Caprae grows to a height of 3 – 5 cm and is therefore suitable as a groundcover. Its preferred shape is spreading, with 4 – 5 main stems. The plant can be sheared once a year to maintain the desired shape and height. In order to maintain its shape, Oxalis Pes-Caprae does not really require pruning: it simply grows to about 4 – 5 cm in height, unless it is in direct sunlight where it will grow taller (up to 15 cm).

Fertilizing

Oxalis Pes-Caprae should be fertilized at the time of repotting. It grows best in moderately fertile soil with a high nitrogen level; try to avoid over-fertilizing Oxalis Pes-Caprae, as its roots are not very deep. It is better to err on the side of too little fertilizer than too much; if you fertilize it too much, the new growth produced by bulbils may be stunted and leafy stems may appear to lack vigor.

Pests and Diseases

Oxalis Pes-Caprae is susceptible to root rot and fungal disease, especially in moist poorly drained soils. But overall, Oxalis Pes-Caprae is not very susceptible to pests and diseases.