Marimo Moss Balls & Water Garden Care Guide

Easy to Care for, Low Light Requirements, Simple


Japanese legend says a chief’s daughter fell in love with a commoner, and her family opposed the union. The two lovers broke free of tradition and ran away together, only to fall into a lake where together, they sank to the bottom. Their love was so strong that they were turned into Moss Balls. Their love is still said to exist in each moss ball today. AND that is why moss balls are considered tokens of love, affection and good luck


  • Moss Balls are actually a form of spherical algae
  • Marimo translates to seaweed ball…so it is kind of redundant to call Moss Balls, Marimo Moss Balls (just saying)
  • Moss Balls do not have an anchor in the center, its just solid algae that radiated from the center
  • Growth Rate: 5mm per year 
  • Moss Balls enjoy low indirect light and cool water


Keep your moss ball where they will receive low to medium indirect light. Direct sunlight can turn your moss balls brown and further degrade them by warming the water they live in. ***Moss Balls are well adapted to low light spaces and can photosynthesize in normal household light. If your space has no window, keep moss ball close to a fluorescent or full-spectrum bulb.

Changing the Water

Change water once every one-two weeks using regular tap water (for best results, allow water to sit out for 24 hours prior to changing the water). You’ll need to change the water more often in summer, as it will heat and evaporate more quickly. ***Clean your moss ball enclosure with a brush if algae begins to grow on tank surface.

Browning + Other Problems

-If your moss ball turns white or losses its vibrant green color, make sure they’re moved to a cooler location with less direct light. They can recover, turning green again. If not, you may add a tiny amount of aquarium ocean salt. If your moss ball turns brown, it is likely dirty and needs a good cleaning under running water. If you moss ball is black and falling apart, it is likely decaying from the inside out. You can try to cut out the contaminated parts, followed up by rerolling of the moss ball and crossed fingers!

Floating Moss Balls?

If you just cleaned your moss balls, there could be little air bubbles trapped in them. Give them a light squeeze in the water to try to get some of the air bubbles out, otherwise, they will settle to the bottom of their enclosure within 1-2 days

Keeping Moss Balls Round

In rivers and lakes, moss balls are jostled around by currents, helping them retain a perfectly round shape. Should you want to retain a lovely round shape, slightly agitate your enclosure once a day. The goal is to have them resting on a side different than the one they were resting on the day before.

Succulent Care

The following is for people who love succulents or have attended one of our succulent workshops and need an assist in maintaining their indoor succulent garden in the PNW.

Light: succulents enjoy full direct sunlight and bright indirect light (keeping them by a window is perfect)

Soil:soil should be well draining. If there is no hole for drainage, then a layer of rock will suffice just fine

Water: Succulents like a good watering, but don’t like their roots to sit in water. Allow soil to dry between each watering. Less is more in the beginning…you can always come back from under-watering, but not over-watering. When beginning to water a new succulent garden, I try and do about 1-1.5oz (shot/espresso glass) of water per plant. It’s enough to notice the weight change, but not enough to over-water

I can’t see the soil…How do I tell if its dry?

  1. Check the soil by putting your finger in it…see if it is damp and cool. If it is, no need for watering. If it is light and dry…that means the soil has dried out.
  2. Another tactic is to lift the pot every day from the time you water. You are trying to feel how heavy it initially is. As the pot gets lighter, the water is drying out. When it feels the same weight for multiple days, you know that the soil is all the way dried out and you can give your garden a good soak again.
  3. When you first start your succulent garden, you should do both of these together, so you can get to know your indoor garden. The more times you do it, the more familiar you become with the process and then easier it is down the road. Remember, at first you will have nothing to compare this to…so just start going through the motions

Fertilizer: Succulents do not require a lot of fertilizer. Watering them once a month with a well-balanced fertilizer is all they need. (10-10-10 fertilizer) As with any house plant, you don’t have to fertilize, but sometimes it’s just what they need to perk them back up. Remember to always dilute fertilizer with water

By Laura Renecker at Model Institution