This big group of plants includes the well-known lucky shamrock.
The diverse oxalis genus comprises hundreds of species.
There’s a wide range of annuals, perennials, and even tropical types of oxalis.
Credit: Laurie Black
Many oxalis are bulb-forming plants, while others form vigorous spreading plants that can create dense colonies.
While many oxalis species have beautiful blossoms, these plants are most commonly grown for foliage.
you’ve got the option to often find them in florist shops aroundSt.
Credit: Laurie Black
Patrick’s Daybecause their leaves resemble shamrocks and are often regarded as a sign of luck.
Their leaves come in shades of purple, burgundy, pink, green, and silvery gray.
The plants bloom with small five-petal blossoms with intricate details on the inner petals.
Credit: Marty Baldwin
These blossoms often begin as tubular flowers that twist open to show off dainty stripes and dark-color throats.
They can be found in shades of pink and white, while other species feature yellow and orange blossoms.
Many oxalis plants are toxic to humans and animals.Keep them away from areas where children and pets play.
Credit: Jay Wilde
Where to Plant Oxalis
Plant oxalis in moist, well-drained soil that is not wet.
Most oxalis plants thrive inpart sun to part shadeareas, and some can handle full sun.
Some oxalis species are attractive houseplants.
Credit: Mike Jensen
Although needs vary by species, in general, oxalis are cool-season plants.
Locate oxalis houseplants in an area without direct sun exposure or high heat.
Of the hundreds of oxalis species, some are invasive and some are not.
Credit: Peter Krumhardt
Check with your local agricultural extension for information in your area before planting.
How and When to Plant Oxalis
Spring is the best time to plant oxalis.
Loosen the soil andamend it with compostto provide excellent drainage for nursery plants or bulbs.
Credit: Kim Cornelison
If you are planting rhizomes or bulbs, plant them only 1.5 inches deep.
If you are planting nursery-grown plants, dig a hole slightly larger than the nursery container.
Remove the plant from the container and plant it at the same depth in the hole.
Backfill, pressing down on the soil with your hands to remove air bubbles.
When planting multiple plants, check the plant nursery tag for spacing recommendations.
Oxalis Care Tips
Growing conditions differ among the numerous species in this genus.
Then you’ve got the option to understand its proper growing conditions.
Some oxalis are alpine plants, woodland plants, or tropical plants, each with different needs.
Light
In general, oxalis are versatile in their sun requirements.
Sun exposure varies depending on the species.
Some species, such as woodland plants, prefer shaded garden controls.
Soil and Water
All oxalis plants preferwell-drainedsoil.
Many species of oxalis tend to be alpine plants; they won’t tolerate any standing moisture.
Woodland plants are generally more tolerant of typical garden conditions.
Many of the bulbous types of oxalis require a period of dormancy.
Alpine plants are typically cool-growing plants.
They don’t care for warm summer weather and may have a summer dormancy period.
Many other species are woodland plants that prefer shaded garden tweaks but tolerate typical garden conditions.
Fertilizer
Fertilize oxalis plants monthly during the growing season (spring and sometimes fall).
Do not fertilize during a period of dormancy or during the winter.
Pruning
Oxalis plants don’t require much attention to pruning.
Cut back flower stalks after they bloom, all the way to the soil line.
To prevent them from reseeding, cut back the flower stalks before they bloom.
Potting and Repotting
Oxalis is an excellent houseplant that likes to be rootbound.
Pot oxalis plants in good-quality potting soil and keep it moist, not wet.
In time, the plant may become crowded in its container.
Pests and Problems
Like many plants, oxalis might attractaphids, mealybugs or whiteflies.
These pests are a bigger problem with houseplants than with those in the garden.
If needed, treat the plant with insecticidal soap orneem oil.
Some oxalis plants spread randomly and can take over a garden if they aren’t contained in some way.
Gardeners need to remain vigilant to control these aggressive spreaders.
However, gardeners who want to propagate the plants can do so by division or seed.
Division:The plant’s dormant period (usually summer) is the best time to divide oxalis plants.
Lift the plant from the ground using a shovel or trowel.
Replant the divisions immediately and water.
Seed:The seeds of most oxalis plants germinate quickly, usually in 714 days.
Cover them with a thin 1/8 to 1/4 inch of soil and water them.
After they germinate, thin the seedlings to the recommended spacing for the species.
Remove the bag when you see growth.
‘Iron Cross’ Oxalis
Oxalis tetraphylla’Iron Cross' offers leaves divided into four leaflets.
Each center is decorated with a purple blotch that looks great against the pink flowers.
It grows 10 inches tall and wide.
Zones 8-9, though it also thrives as a houseplant.
Molten Lava Oxalis
Molton LavaOxalis vulcanicolaproduces stunning orange-chartreuse foliage and decorative golden-yellow flowers all spring and summer.
It grows 10 inches tall and wide.
Zones 9-11, or try it as a houseplant.
‘Purple’ Oxalis
Oxalis regnelliivar.triangularisbears rich burgundy-purple foliage and pink-blushed white flowers.
It grows 12 inches tall and 8 inches wide.
It’s also a good variety to grow indoors.
Redwood Sorrel
ThisOxalis oreganacultivar is native to areas of the Pacific Northwest.
It bears white or pink flowers in spring and summer over silver-splashed foliage.
This groundcover grows 8 inches tall.
It grows 5 inches tall and 6 inches wide in Zones 6-8.
Zinfandel Oxalis
The Zinfandel Oxalis vulcanicola variety bears rich purple foliage and golden-yellow flowers all summer.
It grows 10 inches tall and 12 inches wide.
Perennial in Zones 9-11, it grows as an annual or indoor plant in colder areas.
As long as the leaves open up the next day, the plant is fine.
However, leaves will die back during the plant’s dormancy periodusually one to two months in summer.
When that happens, stop watering and let the leaves turn brown.
New growth will appear at the end of the dormant period.
As the plant enters dormancy, its leaves sag.
Guide to poisonous plants College of Veterinary Medicine and Biomedical Sciences Colorado State University.
Accessed August 2, 2024. https://poisonousplants.cvmbs.colostate.edu/plant/74.
