Irish shamrocks evoke St. Patrick's Day and the green landscapes of the Emerald Isle. But if you're seeking the real McCoy for your garden, you'd better start looking for some four-leaf clovers, because you'll need lots of luck. There is no authoritative version of the shamrock plant. Ironically, history makes it clear that there's also a big difference between shamrocks vs. clover, specifically the four-leaf clover.
What is a Shamrock?
The term shamrock comes from the Irish word seamróg or seamair óg, which translates as "little clover." However, this is rather vague, considering that there are many kinds of clovers and plants that look like clover, but not all are considered to be Irish shamrocks. Historically, a shamrock looks like a clover with three leaves.
What Is Considered a Shamrock?
It's tough to answer the question of whether shamrocks are the same as clover. Five plants lay claim to the designation of an Irish shamrock. But even among the Irish, there's no consensus about which plant is the true Irish shamrock. Of the five plants, the first three are clovers (Trifolium), one is a clover-like plant known as medick, and another is a wildflower that resembles a clover called wood sorrel:
- Lesser trefoil, or hop clover (Trifolium dubium)
- White clover (Trifolium repens)
- Red clover (Trifolium pratense)
- Black medic or medick (Medicago lupulina)
- Wood sorrel: (Oxalis acetosella)
To make matters more confusing, various members of the Oxalis genus, with common names like purple shamrocks (Oxalis triangularis) and wood sorrel (Oxalis montana) are sold as shamrocks for St. Patrick's Day. These clover look-alikes are not related to clover, but they are more easily cultivated as houseplants than real clover.
The History of Four-Leaf Clovers vs. Shamrocks
The shamrock's meaning is tied to the Christian religion. The number three is significant in the Christian religion because of the doctrine of the Trinity. Irish legend has it that St. Patrick, a missionary, bishop, and patron saint of Ireland, demonstrated the principle behind the Trinity using a shamrock, pointing to its three leaflets united by a common stalk. But there is no way of determining with certainty the exact plant referred to in the legend. This explains why the term shamrock is often given to medic, wood sorrels, and true clovers because they all have leaves made up of three leaflets.
By historical definition, an Irish shamrock has three leaves representing the Trinity. So for all of the good luck they allegedly bring, a four-leaf clover is not considered a shamrock, at least in the way St. Patrick made the shamrock famous.
Click Play to Learn the Difference Between Irish Shamrocks and Four-Leaf Clovers
It was ancient Celtic or Druid priests who elevated the rarer four-leaf clovers to the status of good luck charms, potent against evil spirits. This is the origin of the modern belief in their power to bring good luck.
For the most part, the four-leaf clover is not a separate species, just a genetic anomaly. That's why people feel so lucky when they stumble across one. If you want to "make your own luck" and don't mind going outside the Trifolium genus, buy an Oxalis deppei plant. Oxalis deppei is widely sold as the "good-luck plant," because it bears a leaf that always has four leaflets and it looks like a four-leaf clover.
Is Clover Beneficial to Lawns?
Surprisingly, the lucky clover is often looked upon as merely a common lawn weed to be killed. In fact, until recently it was standard practice to include clover seed in lawn seed mixes; it was valued as a built-in fertilizer since it can fix atmospheric nitrogen. Clover snatches nitrogen out of the air, bringing this essential fertilizer down to earth using its nitrogen-fixing bacteria that lives in nodes along the roots.
- Reduces excessive irrigation: Clover tolerates drought conditions better than grass because it has long roots that enable it to access water at deeper levels.
- Looks better longer: It has a lasting green color and stands up better to heavy foot traffic than grass.
- Improves tough soil: Clover tolerates compacted soil better than lawn grass does and its long tap roots also help to aerate your soil.
- Minimizes pollution: Clover lawns minimize the pollution caused by herbicides, pesticides, and chemical fertilizers. In addition, because they usually don't need to be mowed as often as grass lawns, there's less pollution caused by emissions from lawnmowers.
- Attracts pollinators: Clover puts out a mildly attractive flower that draws bees and other pollinators to your landscape.
Wisconsin Shamrocks. University Of Wisconsin Green Bay.
Nelson, Ernest Charles. Shamrock: Botany and History of an Irish Myth. Boethius Press, 1991.
The Science and Secrets of Four-Leaf Clovers. University of Georgia.
Hadden, Evelyn. Beautiful No-Mow Yards: 50 Amazing Lawn Alternatives. Timber Press, 2012.
Agriculture and Air Quality. United States Environmental Protection Agency.
Miller, G. Lawns. North Carolina Extension Gardener Handbook, edited by K.A. Moore and L.K. Bradley, NC State Extension, 2018.