Shamrocks and Four-Leaf Clovers: What's the Difference? (2024)

Many of us rememberhunting for that elusive “four-leaf clover” as children, and we’ve all seen that green shamrock on St. Patrick’s Day. That brings us to today’s garden musings. Let’s talk about what a shamrock really is—and what itisn’t!

What IsaShamrock?

The shamrock is asymbol that we commonly associate with St. Patrick’s Dayand with Ireland. It can be seen all over St. Patrick’s Day decor, representing the rebirth ofspring.

Sometimes, the shamrock is depicted as a four-leaf clover, but this isn’t quite accurate.Traditionally, a shamrockis athree-leafclover.

Why three leaves and notfour?According to legend,St. Patrick used a three-leaf shamrock to explain the Holy Trinity, with one leaf representing the Father, the Son, and the Holy Spirit,respectively. More recently, the four-leaf clover has also come to represent the Holy Trinity, with the fourth leaf symbolizing God’sGrace.

TheTrueShamrock

The word “shamrock” comes from the Irish word Seamróg, meaning “little clover”or “young clover,” but there isn’t a consensus on which species of clover is the “true” shamrock. In fact, there area few plants that go by thisnickname!

In Ireland, the plants that are most often associated with the name “shamrock” are the suckling clover (Trifolium dubium) and the white clover (Trifolium repens). Both clovers are native to Europe but can be foundthroughout the world today.Their genus name, Trifolium, means “having three leaves”—an appropriatedescription!

According to Encyclopedia Britannica, a number of other similar-looking plants go by the name“shamrock”:

”Shamrock[refers to] any of several similar-appearing trifoliate plants—i.e.,plants each of whose leaves is divided into three leaflets. Plants called shamrock include thewood sorrel(Oxalis acetosella) of the family Oxalidaceae, or any of various plants of the pea family (Fabaceae), includingwhite clover(Trifolium repens),suckling clover (T. dubium), andblack medic (Medicago lupulina). Wood sorrel is shipped from Ireland to other countries in great quantity for St. Patrick’sDay.”

As mentioned, “shamrock”canalso refer to a plant called common wood sorrel (Oxalis acetosella). Wood sorrel looks very similar to clover, though the plants are not related. Tropical relatives of wood sorrel are often sold in stores as “shamrock” houseplants since they’re better suited to the indoor environment than cloverspecies.

How Rare Is aFour-Leaf Clover? Why Are TheyLucky?

As kids, we would spend hours searching for thatlucky four-leaf clover—and often comehomeempty-handed!

A four-leaf clover isn’t a special variety of clover; it’s just an unusual mutationof a three-leaf clover, but it’s a “lucky” symbol because it’s so hard to find.In fact, your chances of finding a four-leaf clover are 1 in 10,000!That’s where the luck comes in, apparently. According to popular lore, if you do find a four-leaf clover, giving it to someone else doubles yourluck.

Traditionally, four leaves were considered lucky because theyreflectedthe shape of a cross and were thought to be magical or sacred. Eve supposedly took a four-leaf clover with her when she was banished from the Garden of Eden,too.

In the Middle Ages, it was believed that carrying a four-leaf clover would enable you to see fairies, recognize witches and evil spirits, and be protected from the evil eye. Even dreaming of clover was supposed to bring goodluck.

Superstitions aside, clover is a valuable plant in many ways. Bees and other pollinators can’t resist their flowers (red clover is especially attractive to bumblebees), and the plants can be turned into the soil as green manure, too. Additionally, the roots host nitrogen-fixing bacteria that enrich the soil, and the plants are high-quality forage for many animals. The reasons to grow clover areendless!

The Value ofClover

In recent years, the idea of growing clover has been making a comeback. White clover (Trifolium repens)is well known for crowdingout broadleaf weeds while growing harmoniously with grass. It will thrive in areas that are poorly drained or too shady for a conventionallawn, making it a great grassalternative.

As a legume, clovers have the ability to convert nitrogen into fertilizer using bacteria in their root system (a process called “nitrogen fixation”), practically eliminating the need foradditionalfertilization.

Despite today’s push for perfectly green lawns (which often involves a lot of chemicals), clover was not always viewed as a “weed.” The University of Minnesota Extension Service points out that, until relatively recently, it was standard practice to include clover seed in lawn seedmixes:

“Until the 1950s, clover was includedin lawn seedmixes, as it was regarded as a prestigious lawn plant. It may be considered an attractive, low-maintenance ground cover that is soft to walk on, mows well and will fill in thin spots in ayard.”

Today, it seems Clover is returning as a more eco-friendly lawn alternative. Since it is nitrogen-fixating, it can supply its own nutrients to poor soil. Overseeding clover seed into your existing lawn is an easy way to establish a clover lawn. For lawns, the most popular is the white cloverbecause it is relatively low growing, tolerates close mowing, andoutcompetesweeds.

See more about growing a clover lawn.

The False Shamrock:Oxalis

Thelast piece of the shamrock puzzle is a houseplant that also goes by thename “shamrock.” It usually crops up in grocery stores and nurseries around St. Patrick’s Day. This plant is not related to clover (the “true” shamrock) but is in the same genus as wood sorrel (Oxalis).

Oxalis are native to many regions of the world, but they’re most numerousin the tropics, which is where the houseplant species come from. Depending on the species, theycan have green or purple leaves and white or pink flowers, and some cultivars, such as ‘Irish Mist,’ have green leaves flecked with white. The whole plant is photophilic, meaning the leaves and flowers close up at night and open wide again in themorning.

Oxalis can be grown outdoors in the spring and summer in Hardiness Zones 6 to 11, but they also make forgreat houseplants year-round. They like bright, indirect lightand tend to bloom in fall, winter, orspring.

Since they are grown from bulbs, let them dry out a bit between waterings to prevent rot. Don’t fret if your indoor Oxalis loses all its leaves in summer. It isn’t dead. It just needs a dormant period, so let it dry out and put the pot in a dark place until it decides to resume growth in a few weeks. As soon as new leaves appear, bring the plant into the light and resume watering. These plants are low-maintenance andlong-lived.

Here are a few of the more popular Oxalis houseplantspecies:

• Sometimes called False Shamrock, Oxalis regnelliiare native to South America. Pictured above, they have heart-shaped leaves instead of the clover’s oval-shapedleaves.

• Purple Shamrock (Oxalis triangularis) is a subspecies of O. regnellii that hails from Brazil. It has large, handsome purple leaves and pale lavender-pinkflowers.
• Lucky Leaf or Lucky Clover (Oxalis tetraphylla) is also known as four-leaved sorrel. Native to Mexico, it has four split green leaves with a dark maroon eye. The trumpet-shaped flowers of ‘Alba’ are white, and ‘Iron Cross’ has pinkflowers.

Oxalishouseplants all contain oxalic acid, the same chemical that makes rhubarb leaves and daffodils toxic. If eaten in large quantities, they can be poisonous to pets and small children, so don’t go feeding the leaves to your petrabbit!

Now that you know the true identity of the shamrock, check out our St. Patrick’s Day page for more history andlore!