How to: Care for your Oxalis this St. Patrick's Day!

The four-leaf clover, as you know, is extremely rare and represents good luck. It is actually a mutation that occurs once in every ten thousand clover leaves!

Everyone loves St. Patrick’s Day!  The Irish are a generous fun-loving people who don’t mind one bit if we all treat St. Patrick’s Day as our own.  It is globally celebrated with the wearing of the green, dancing, drinking green beer and searching for the elusive leprechaun and his treasure of gold.  For the people of Ireland it is a national holiday which celebrates the life and death of St. Patrick; the patron saint of Ireland.  Green is worn to celebrate the beautiful green landscape of The Emerald Isle.

The symbol of St. Patrick is a three- leaf shamrock; not a four leaf clover. The four-leaf clover, as you know, is extremely rare and represents good luck. It is actually a mutation that occurs once in every ten thousand clover leaves! 

A favorite houseplant to purchase at this time of year in celebration of St. Patrick’s Day is the Oxalis or false shamrock. There are many species of Oxalis.  They can be bulbous, root-forming or rhizomatous.  They flower in shades of yellow and pink or white from spring to autumn.  Their leaves and blooms open during the day and close at night. They will also close if placed in too much sun.  

There are two varieties of Oxalis that make great houseplants that will live for many years. It is not unusual for an Oxalis to be passed down many generations in a family.



The Purple Shamrock (Oxalis r. triangularis) has striking purple, paper-thin triangular leaves and lavender-pink flowers. The plant can become quite large: sometimes reaching a height of 12 inches and spread of 20 inches.  The Green Shamrock (Oxalis regnellii) has green triangular leaves with white flowers.  It is a smaller oxalis only reaching a height and width of 8-10 inches.  No matter which species you choose, their care is basically the same. 

Indoors, oxalis does best in bright, indirect light and room temperatures of 15 – 21 degrees C. A room with morning sun is ideal.  Too much sun will burn and brown the leaves.  They prefer a  tropical plant soil mixed half and half with succulent soil, extra perlite and a pot with good drainage.  Drainage is always important but especially for Oxalis – they need a fast- draining soil so the root system will not rot. Water only when the top two inches of soil is dry.  The plant should not sit in water at any time.  During spring and summer you can fertilize once a month with a half strength application of 20-20-20 all purpose water soluble fertilizer. In winter, water sparingly and do not fertilize until spring.



One or more times during the year, your oxalis will go dormant.  Many people think their plant has died but its just having a rest.  The purple shamrock will usually rest for about a month.  The green shamrock will be dormant for 2-3 months. When you notice the leaves are flagging or are turning brown/yellow the plant is telling you it is going into dormancy.  Stop watering and let the soil totally dry out.  Cut back the brown leaves at the soil line.  Put the plant in a cool, dark location but do place it where you can keep an eye on it. Never fertilize during dormancy. 

After a few weeks new growth will begin to emerge.  At this point you can repot and move the root ball to a size larger pot and begin watering again or keep it in its original pot and begin watering again. Do not overwater as too much water will send it back into dormancy.  Signs that your Oxalis needs repotting are roots coming out of the drainage holes or the rhizomes are pushing their way out of the top of the soil and spreading to the edges of the pot.  If necessary, you can also repot after flowering has finished.

The time to propagate your Oxalis is after dormancy.  Instead of repotting the entire root ball you can gently separate the bulbs or rhizomes from the main root ball and repot into smaller containers with fresh soil.  The main root ball can then be put back into its original pot and backfilled with fresh soil. 

Lastly please be aware that oxalis is toxic to cats and dogs.

Have a fun-filled and safe St. Patrick’s Day!  Erin Go Bragh!!

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