Oxalis: “False” Shamrocks for a Happy St. Patrick’s Day!

Happy St. Patrick’s Day! Today is full of traditions for the Irish (and the Irish-for-a-day), and nothing is more symbolic of the day than the shamrock, Ireland’s traditional good-luck plant. True shamrocks (Trifolium spp.) are native to Ireland and Europe, though they’ve been introduced around the world, and are members of the pea family (Fabaceae).

False Shamrocks, though, are found around the world – there are over 900 species. All part of the genus Oxalis, they’re often sold as “Shamrocks” since they resemble true shamrocks so closely, even though the two are only distantly related. Some varieties are known as wood sorrel, and these are often the types that “invade” lawns.  (Learn more about the more than 900 species of Oxalis here).

Oxalis violacea, known as Violet Woodsorrel, is native to the U.S. and can be grown outdoors in zones 5 – 10. In hotter climates, it will go dormant in the heat of summer, but will return when temperatures cool down again in the fall. The flowers vary from violet to pink, and the big-leaved foliage is fresh and pretty. Perhaps because it’s native to the U.S. and not considered all that “exotic”, it’s a little harder to find, but try the Odyssey Bulbs Catalog or Prairie Moon Nursery.

Violet Woodsorrel (Oxalis violacea)

The more ornamental Oxalis varieties are incredibly easy to grow in zones 6 and higher, and can be grown in containers and moved inside for the winter in colder zones.  They are generally sold as spring-planted bulbs or tubers, and are both inexpensive and easy to find. Here are a few popular species for you to try:

Oxalis deppei 'Iron Cross'

Oxalis deppei syn Oxalis tetraphylla – This species is often called the “Good Luck Plant” due to its four-leaved clover foliage. One particularly famous cultivar is ‘Iron Cross’, which has distinctive purple markings on the inner parts of the leaves. Try traditional ‘Iron Cross’  from Easy to Grow Bulbs, or a deep-pink flowered variety from American Meadows. (Native to Mexico.)

Oxalis regnelli – You’ll see this variety for sale pretty frequently this time of year, usually labelled as “Lucky Shamrock”. Grow them outdoors in zones 6 and higher, and in containers anywhere. Try the traditional white-flowered Lucky Shamrock, or a cultivar like ‘Fanny’ with pink flowers, both available from Easy to Grow Bulbs. (Native to South America.)

Oxalis triangularis – The purple foliage of this Oxalis makes it a popular houseplant. It can be grown outside in zones 7 and higher. The purple leaves are complimented by soft pink flower clusters. Easy to Grow Bulbs offers a bag of 25 for about $10. (Native to Brazil.)

Notes:

• Some varieties of Oxalis are considered invasive in some areas. Check your local gardening information before planting.
• Woodsorrels are edible and consumed around the world. They are safe to consume in small amounts, but when eaten in large amounts, the oxalic acid they contain can cause kidney issues. If in doubt, consult your doctor before consuming.

Do you grow Oxalis? Tell us which varieties you prefer and where you grow them in the comments below!