Gardening 101: Marimo Moss Balls

I have been a doting houseplant parent for a very long time. I go so far as to propagate the ones I have to make more for free, like my spider plants and pothos. I’ve been known to give my houseplants foliage baths by wiping down their dusty leaves, and even, on occasion, ask my houseplants how they are doing. But there is one houseplant I own that requires basically no care and is both charming and strange at the same time: Marimo moss balls.

N.B.: Some readers have pointed out that earlier this year, U.S. Fish and Wildlife Service began to stop the importation of moss ball balls contaminated with invasive zebra mussels. Mine are so old that I wasn’t aware of this problem. If you bought yours after February 2021 (especially the Betta Buddy brand), please properly destroy or quarantine them due to possible zebra mussel contamination—and go here for instructions.

Please keep reading to learn about these moss balls:

Okay, maybe Marimo moss balls do look like a fuzzy green dog toy submerged in water, but quickly move past that because these soft spheres are simply fascinating. Turns out, they are actually rare forms of slow-growing strings of algae that form into balls as they roll around on the edges of shallow freshwater lakes in places like Japan and Iceland. Even more interesting, these velvety balls can reproduce and live for more than 100 years (can you say, heirloom plant?).

Marimo moss balls also come with their own legend. According to Japanese folklore, there once was a tribal chief who forbade his daughter and her commoner lover to be together so the couple ran away. Unfortunately, they fell into a nearby lake and sank to its depths where they transformed into Marimo balls. This is why the balls are believed to have the power to mend relationships and are considered the love plant. Whether you believe this story or not, once you touch one of these squishy, fuzzy objects, you may develop a total crush on them.

How to care for your Marimo moss balls:

• Place your Marimos in a clean container filled with filtered cold water and decorative gravel.
• Situate the container in a spot that receives low to medium light. Pro Tip: direct sun will create excess algae and potentially brown the balls.
• Marimo balls can live in a freshwater aquarium, but I’m told by my local pet supply folks that finned friends (not snails, though) might snack on Marimos.
• Change the water every couple of weeks. If the sides of your container get slimy and green, clean that too.
• Marimos require zero fertilization.
• To keep their round shape, occasionally rock the water to mimic their native lake shore habitat.
• Want more moss balls? You can propagate them by carefully dividing one into two and rolling them around in your hands to re-form a ball.

For more on unusual plants, see:

• Gardening 101: Air Plants
• The Miracle Season: A Resurrection Plant That Can Come Back to Life
• Kokedama String Balls: A DIY Hanging Garden