What Makes Oxalis So Special?

Oxalis is special for its distinctive, clover-like foliage and its often charming, delicate flowers. Many species have leaves that fold up at night or on cloudy days, adding an interesting element of movement to the garden. Some varieties have strikingly colored foliage, ranging from deep burgundy to bright chartreuse. It is the combination of clover-like leaves, often with interesting colors and movement, and the dainty flowers that make them appealing. However, it is crucial to note that some Oxalis species can be very invasive, so careful selection and management are essential.

Description

• Growth Habit: Varies depending on the species. Some are low-growing and spreading, forming mats or clumps, while others are more upright. Some grow from bulbs or rhizomes.
• Height: Ranges from a couple of inches to over a foot tall, depending on the species.
• Foliage: The defining feature! Typically, trifoliate (divided into three leaflets), resembling clover. Leaf color varies widely, from green to purple, burgundy, or even patterned. Many species exhibit nyctinastic movement (folding up at night).
• Flowers: Five-petaled, often cup-shaped or funnel-shaped. Colors include white, pink, yellow, and red. They can bloom at various times of the year, depending on the species.

Details Gardeners Care About

• Sunlight: Varies depending on the species. Some prefer full sun, while others prefer part shade or even full shade.
• Soil: Generally, prefers well-drained soil that is rich in organic matter. Some species tolerate poor soils.
• Water: Most species prefer consistent moisture, but some are quite drought-tolerant once established.
• Hardiness: Varies widely depending on the species. Some are hardy to USDA zone 3, while others are only tropical.
• Invasiveness: This is crucial! Some Oxalis species, particularly those with bulbils or spreading rhizomes, can be very invasive and difficult to eradicate. Be very careful when choosing which species to plant.
• Deer Resistance: Generally considered deer-resistant.
• Attracts Pollinators: The flowers attract bees and other pollinators.

Native Habitat

Oxalis species are found worldwide, in a wide variety of habitats:

• Woodlands
• Meadows
• Lawns
• Gardens
• Disturbed areas

Landscaping Design Tips

• Groundcover: Some low-growing species can be used as a groundcover in shady areas (be very careful about invasiveness).
• Rock Gardens: Suitable for rock gardens, especially the smaller, well-behaved species.
• Containers: Many Oxalis species are excellent for containers, where their foliage and flowers can be appreciated up close, and their spread can be controlled.
• Borders: Use them as an edging plant in borders (again, be mindful of invasiveness).
• Houseplants: Some species make excellent houseplants.
• Woodland Gardens: Shade loving varieties work well

Planting and Care

• Planting Time: Varies depending on the species and whether it is grown from bulbs, rhizomes, or seeds. Spring or fall are generally good times.
• Spacing: Space plants according to their expected mature size.
• Planting Depth: Plant bulbs or rhizomes at the appropriate depth (usually a few inches).
• Watering: Water regularly, especially during dry periods, but avoid overwatering.
• Mulching: Mulch can help retain moisture and suppress weeds.
• Fertilizing: Generally, doesn't need much fertilizer. A light application of compost or a balanced fertilizer in spring can be beneficial.
• Deadheading: Deadheading (removing spent flowers) can prolong the bloom period and prevent seed formation (which can help control spread).
• Pruning: Not usually necessary, but you can cut back the foliage if it becomes leggy.
• Division: Many species can be propagated by division of bulbs or rhizomes.
• Controlling Spread: If you have an invasive species, be vigilant about removing unwanted plants, including any bulbils or rhizomes.
• Weeding Weeding out unwanted plants helps to keep the spread in control

Taxonomy (Simplified)

• Genus: Oxalis
• Family: Oxalidaceae (Wood Sorrel family)
• Common Species (Examples):
• Oxalis triangularis (Purple Shamrock, False Shamrock) - A popular houseplant with deep purple foliage.
• Oxalis pes-caprae (Bermuda Buttercup) - A very invasive species with yellow flowers (avoid planting).
• Oxalis corniculata (Creeping Wood Sorrel) - A common weed with yellow flowers.
• Oxalis oregana (Redwood Sorrel) - A shade-loving, non-invasive species native to the Pacific Northwest.
• Oxalis versicolor (Candy Cane Sorrel) - Unique, striped flowers.

Morphology (Simplified)

• Stems: Can be slender and creeping or more upright.
• Leaves: Typically, trifoliate (three leaflets), resembling clover. Often exhibit nyctinastic movement.
• Flowers: Five-petaled, often cup-shaped or funnel-shaped.
• Roots: Can be fibrous roots, bulbs, or rhizomes, depending on the species.
• Fruit: A capsule containing small seeds.

Other Insights

• Invasiveness (Again!): This cannot be overstated. Some Oxalis species are extremely invasive and can be very difficult to control once established. Research the species thoroughly before planting it in your garden.
• Edibility: Some Oxalis species have edible leaves and flowers, which have a sour, lemony flavor (due to the presence of oxalic acid). However, they should be eaten in moderation, as oxalic acid can interfere with calcium absorption.
• Nyctinastic Movement: The leaf-folding behavior of many Oxalis species is a fascinating adaptation that helps them conserve water and protect themselves from damage.
• Variety: There is a huge variety of Oxalis species, with a wide range of foliage colors, flower colors, and growth habits.
• Weed: Many species are considered weeds.

In summary, Oxalis offers a range of beautiful and interesting plants, with their distinctive clover-like foliage and charming flowers. However, the potential for invasiveness in some species is a serious concern. Choose your species carefully, be aware of its growth habits, and be prepared to manage its spread if necessary. If you select a well-behaved species and provide the right conditions, Oxalis can be a delightful addition to your garden or home.