Yes, it's true. You do not have to be Irish to wear green on St. Patrick's Day, and you definitely don't need a green thumb or Leprechaun to grow Shamrocks indoors! "Most" shamrocks sold in garden stores and florists are a member of the Oxalis family, of which there are over 300 species. Some have green leaves, some maroon; some grow from bulbs some from tubers, and most fold their leaves at night and open during the day. White clover, black medic, hop clover, and four leaf clovers have also been portrayed as shamrocks, but the true Irish shamrock is Trifolium dubium, which is a yellow flowering clover, is not easy to grow indoors - thus it's the Oxalis plants, which are fairly easy to grow indoors, that's sold instead for your potted shamrock. Growing Shamrocks Indoors:
-All shamrocks need lots of light for growing and flowering indoors. Be careful of the hot afternoon sun during the summer. Using artificial lighting? Keep it on for at least 12 hours each day.
-Keep your shamrocks evenly moist. They love moist yet well drained soils. Let it dry ever so lightly between watering.
-They prefer cooler temperatures, especially during the flowering times. Try for the low 70's during the day, and 55-65 degrees at night. Warmer temperatures will encourage dormancy quicker.
-Feed shamrocks every 2-3 weeks during the flowering and growing times. Once flowering has stopped and growth slowed, cut back to once a month. Water soluble fertilizers work best.
-Shamrocks can remain in the same pot for several years. If repotting is needed, do this at the end of the dormancy period. Division can occur at this time as well.
-Snip off spent flowers stem and all as well as yellowed leaves. An occasional gentle shower in the sink will help clean dust off the leaves.
-Most (not all) shamrocks will go thru a dormancy period(s). The leaves will yellow, the plant gets a tired look, and just shuts down. Stop watering, remove dead foliage, and place pot in a cool dark area. When new leaves begin to appear, bring it back out and start the growing cycle all over again.
Spots on leaves - usually water spots. Shamrocks have very few diseases or pest problems.
Plants wilt - Root system too dry for too long. Soggy wet roots or being too cold will also cause wilting.
Yellow Leaves - Too much water. Plants getting too tall and thin - Not enough light, or temps too warm.
No Blooms - Plants too young, not enough light, or just too tired and need a rest period. (Rest periods may last for a couple months.)