The specific epithet in the scientific name of mountain wood-sorrel (Oxalis montana) is “montana,” which means “mountain.” That’s because it’s a shade-loving species that thrives best at higher elevations. This is a plant that’s indigenous to eastern North America. Other names for it include wood shamrock and white woodsorrel.
I. Appearance and Characteristics
Oxalis montana is a species of flowering plant in the family Oxalidaceae known by the common names mountain woodsorrel, wood shamrock, sours and white woodsorrel. It may also be called common woodsorrel, though this name also applies to its close relative, Oxalis acetosella.
This species is a perennial herb native to eastern North America, including eastern Canada and the north-central and eastern United States, and Appalachian Mountains. The Latin specific epithet montana refers to mountains or coming from mountains.
Oxalis montana is a perennial herb which grows in patches connected by subterranean rhizomes. There are no stems, just clumps of leaves growing to about 10 centimetres (3.9 inches) in maximum height.
The leaves are each made up of three heart-shaped leaflets. The leaflets move, folding and unfolding, in response to sunlight.
There are two types of flowers, blooms that open and cleistogamous flowers that remain closed and self-pollinate. The flower color is variable. Environmental factors may cause variation; flowers growing at higher elevations have less color in the veins on the petals, while the veins of those at lower elevations have a deeper pink-purple coloration. The fruit is a capsule. The plant reproduces sexually by seed and asexually by sprouting large colonies from the rhizome. Some populations produce no flowers in a given season and reproduce only vegetatively.
This plant is a climax species, occurring in mature forests and tolerant of shade. It is a dominant herb in a number of ecosystems, such as the forests of the Appalachian Mountains. It occurs there in the understory of red spruce (Picea rubens) and balsam or Fraser fir (Abies balsamea or A. fraseri).
It is also dominant in northern hardwood forest habitat and its ecotones, in the understory of red or sugar maple (Acer rubrum or A. saccharum), yellow birch (Betula lutea), and American beech (Fagus grandifolia). Other dominant understory species growing with it include false lily-of-the-valley (Maianthemum canadense), goldthread (Coptis groenlandica), starflower (Trientalis borealis), and woodferns (Dryopteris spp.).
This plant’s extensive root network helps it stabilize the soil. It can grow on flat ground or steep slopes. The climate is often cool and moist, with high humidity and precipitation, including fog drip, and areas of long-lasting snowpack. Wildfire is uncommon.
II. How to Grow and Care
Mountain wood-sorrel thrives in cool, shaded habitats with moist, well-draining soil, reflecting its native woodland environment. Special care points include avoiding over-watering and ensuring it has enough shade to protect its delicate foliage. Mountain wood-sorrel is fairly easy to care for, as it adapts well to suitable indoor environments and requires minimal intervention once its basic needs are met.
Sunlight
Mountain wood-sorrel thrives in partial sun conditions, which offer an equilibrium between sun exposure and shade. The ideal light environment should provide mountain wood-sorrel with ample but diffused sunlight, avoiding the harshness of midday sun. While mountain wood-sorrel tolerates a degree of variation in light, excessive direct sunlight may result in leaf scorch, whereas insufficient light may lead to etiolated growth and poorer flower production.
wood-sorrel has adaptive traits such as leaf movements, where leaves fold in response to changing light levels, to maximize light absorption without incurring damage. Optimally positioned in outdoor settings, mountain wood-sorrel does well under the dappled light of trees or the shelter of taller vegetation, which simulate its native woodland habitats.
Temperature
In tropical and temperate regions, mountain wood-sorrel can be quite resilient little plants, even though they are native to South Africa and Brazil. The indoor temperature is quite suited for them, so their optimum is between 16 to 21 ℃. They require moisture, but not excessive so they should be watered every 2-3 days, ideally when the topsoil dries out. If you are growing mountain wood-sorrel in your garden, water them daily only during prolonged droughts or if there is little rainfall in your area.
Watering
Originating from moist, forested regions, mountain wood-sorrel thrives in conditions that mimic its native understory habitat, requiring consistent moisture without waterlogging. It is moderately drought-tolerant but prefers a stable environment with regular hydration, necessitating watering every week to maintain its delicate balance. Cultivated primarily as an ornamental indoor plant, mountain wood-sorrel benefits significantly from increased humidity levels which support its lush foliage and enhance its natural flowering cycle.
Soil
Mountain wood-sorrel can be sensitive to overwatering as soggy soil can promote the bulb root rot. This means that you should check for drainage in your garden before you choose your planting site and if you plan on growing them potted indoors, make sure that your container can be drained from the excess of water. Mountain wood-sorrel requires neutral to slightly acidic soil (pH 6.0-6.5). Regarding the soil type, mountain wood-sorrel is not too specific, so a well-drained, store-bought potting mix will work just fine.
Fertilizing
For mountain wood-sorrel, use balanced nutrition fertilizers to enrich soil and bolster vigor. Apply a diluted liquid fertilizer monthly during the growing season, spring through fall, at half the recommended rate. This practice promotes robust growth and abundant flowering. During dormancy in winter, cease fertilization. Use caution: over-fertilizing can damage mountain wood-sorrel. For safety, wear gloves and avoid direct contact with the fertilizer. Adjust fertilization if mountain wood-sorrel shows signs of stress or excessive growth.
Planting Instructions
Mountain wood-sorrel generally blooms in the summer, so it should be planted during springtime, especially if planted in the garden. As mountain wood-sorrel requires proper drainage, choose locations in your garden in which the rainwater does not pool. Also, take into consideration the different sunlight requirements according to the mountain wood-sorrel species that you plan to plant in your garden. It is smart to plant bulbs and not from the seed, as you are never sure if all seeds will germinate.
Loosen the soil and place the bulbs down about 4 cm and do not worry about on which side you place the bulb, as they will always grow upwards. Mountain wood-sorrel looks stunning and grows well in groups, but be sure to make a bit of space between the bulbs (8 to 10 cm). If grown in pots, place up to 8 bulbs in a 15 cm container, up to 14 bulbs in a 20 cm pot and up to 20 bulbs in a 25 cm pot.
Mix in some compost with the extracted soil, return the soil around the bulb and water generously at the end so the soil settles well. They should start sprouting after a couple of weeks.
Pruning
Mountain wood-sorrel requires pruning only when entering their winter dormancy. When the foliage starts to wither, this is the sign that your mountain wood-sorrel is entering its dormant phase. After the leaves turn brown, just remove the dead foliage and don’t worry, this is normal and they will return in the next growing season, which could start anywhere from 2 to 4 weeks. Remember to always disinfect your pruning tools because this minimizes any chances of cross-contamination.
Propagation
Mountain wood-sorrel is commonly propagated through the reproduction of stem bulblets. These bulblets, or ‘buds’, grow along the stalk and can be gently removed when sizable enough. They should then be planted in moist, well-drained soil with partial shade, ideally mimicking their native forest floor conditions. Care includes ensuring the soil remains humid but not waterlogged, promoting the development of a healthy root system.
Transplanting
Best to relocate mountain wood-sorrel from the awakening of early spring to the full bloom of late spring, ensuring robust growth. Choose a shaded, well-drained spot and keep the soil moist for optimal establishment.
Repotting
For the petite mountain wood-sorrel, repotting every 2-3 years supports its seasonal growth cycle. Best done in spring, choose a slightly larger pot with drainage to accommodate its delicate roots. Use a fresh potting mix to refresh the soil. After repotting, ensure moist soil and partial shade to minimize stress and encourage robust growth of this charming ground cover.
III. Uses and Benefits
- Culinary uses
The species is sour in flavor, and can be added to soup or salad. It contains oxalic acid, which can be poisonous in high quantities.
