Terrarium Maintenance to keep your garden green

By Tovah Martin, author of The New Terrarium

A terrarium shouldn’t be forgotten

Your interaction with a terrarium shouldn’t end when you’ve tucked in the last plant and closed the lid. Terrariums are low-maintenance, to be sure, but that doesn’t mean they should be forgotten.

Hopefully, you’ll be so riveted by your crystal kingdom that you’ll be inspired to invest plenty of time admiring the small masterpiece you’ve created.

And while you’re at it, you might want to do a little upkeep and keep your small world perking happily along.


A terrarium benefits from maintenance

  • Most often, keeping a terrarium content is merely a matter of turning the terrarium occasionally. If the light source that’s illuminating the plants inside comes only from one direction, rotate your terrarium every week or so. And make sure that the sun hasn’t shifted seasonally. You don’t want your terrarium to be sitting in a very bright or too shady of a situation.
  • Every two or three weeks, it’s wise to ventilate a closed terrarium for a few hours. After you’ve aired it out, close the lid again and wait to see if condensation builds up on the glass. If so, then it’s good to go for a while. If not, then open it and give it a small drink of water.
  • Fertilizing a terrarium is not necessary – after all, you want to keep the players in your mini world from growing into Jolly Green Giants.
  • When you’ve got the terrarium open for ventilation, examine the inside for dead branches, flowers that have faded, and anything that could lead to problems. Whisk the dead stuff away.
  • At the same time, make certain that no mold or fungus is threatening your miniature peaceable kingdom. The instant you see a problem, escort it off the premises. With mold or similar problems, contain the crime scene by putting a tissue over the area. Then scoop it away in a manner least likely to release spores. Monitor the terrarium carefully for future outbreaks.
  • Although it’s desirable and delightful when a terrarium begins to fill in and the plants happily coexist and thrive, you don’t want the residents competing for real estate.
  • When the plants inside a terrarium start encroaching on each other’s turf, divide off a section of the plant (for a clean break, you might need to cut the part to be removed with a knife) or, if it’s more feasible, lift the whole plant, diminish it, and replant a portion. When replanting, take care to bury all the roots and firm them into the soil. That’s critical. And always water a newly transplanted plant immediately after the transition.
  • When plants begin to press against the glass, they need to be pruned or moved to a larger vessel. Mosses can expand like sponges. Simply take scissors and give them a haircut to diminish their girth.
  • While you’re at it, clean the glass. Avoid using cleaning fluids of any sort, simply moisten a paper towel and wipe any schmutz away. Cleaning the glass should be done on an “as needed” basis. But address the chore fairly regularly. A few strategic swipes with a cleaning cloth will keep the terrarium plants healthy and give you a clear window on your small world.