Thank you to everyone who visited me at the Harvard Square Holiday Fair in December! I had a wonderful time, and really enjoyed meeting new people and talking about plants and moss. Please get in touch via the links below if you have questions about your new terrarium.
Happy New Year for 2024!
I started making terrariums over the first winter lockdown. I often hike in the woods after work, foraging for mushrooms in season, and just enjoying being in nature. In late Fall I created a couple of moss terrariums so I could watch moss growing indoors during the winter months when moss in the woods was covered in snow. Since then, I have been collecting plants and ferns suitable for terrariums. I collect moss sustainably away from conservation or public land. I live and work at Western Avenue Studios and Lofts in Lowell, MA and most months I show my terrariums during Open Studios day. Besides making terrariums I am also a clothing designer, knitter, hiker and mushroom forager.
Terrariums are a easy, low-fuss way to have beautiful growing plants in your home.
Closed terrariums create a self-sustaining ecosystem with a water cycle of evaporation and condensation that keeps plants healthy. Plants that can be hard to grow in dry indoor air will flourish in the steady humid air of a terrarium.
Terrariums require little ongoing care once a few basic needs are met.
Your new terrarium needs bright indirect light, with no direct sun. So no sunny south-facing windowsills or dark corners. In direct sun your terrarium will turn into a greenhouse and cook the plants. In dark areas your terrarium plants will grow weak from lack of light. Plants with pink/colored leaves will turn green. You can measure light with a free light meter phone app. Look for a reading of approx 350 to 400 foot candles to start. Over time you might find a lower reading works fine depending on the conditions. Or use an warm white LED lamp to supplement the existing light alond with a timer set for between 8 to 12 hours of light a day, again depending on the conditions. Light meter apps are also useful for growing houseplants. Keep in mind that extremes of heat, like a cold windowsill in winter or a hot radiator, should be avoided. It will take a few days for your terrarium to adjust to its new home. Once you have found a good spot it’s best not to move it around too much.
Closed terrariums will only need additional water once the existing water starts to evaporate and escape through gaps around the lid. If there is no condensation forming this is likely a sign your terrarium needs a misting of water. Mist your terrarium lightly using a spray bottle. Your terrarium does not need watering like a regular houseplant would. Use distilled or rainwater rather than water from the faucet. Mist your terrarium when the plants and moss need it, not on a schedule. Your terrarium may need misting when you first bring it home, as it adjusts to its new home. Once established it may only need misting once every few months. Your terrarium has a bottom layer of charcoal forming a false bottom which keeps the water clean and acts as a reservoir. It’s best not to oversaturate the soil or soak the plants.
Condensation will form readily on the inside walls of your terrarium as a natural part of the water cycle. You can carefully run a finger around the walls to clear the excess or use a microfiber cloth which also helps to keep the glass clean. If you over-mist, leave the lid off for a few hours to let excess water evaporate.
The plants in your terrarium will grow over time and eventually you will need to trim them with small scissors and remove the trimmings with tweezers. Always remove any dead leaves and trim off dead plant tissue. Rotting plant material can lead to disease. You can often use the cuttings to grow new houseplants. You may want to replace plants that have grown too big.
Low Light Problems
If a pink/colored plant is growing green leaves in low light, trim off and remove all the new growth, and move the terrarium to a position with more (indirect) light. Do the same for etiolated (stringy) growth. If you see white fuzzy mold remove with a moistened Q tip as soon as possible and move the terrarium to a position with more (indirect) light. Use room temp chamomile herbal tea to prevent and treat mold in terrariums. It doesn't harm the plants but can only help with mild mold problems. Use with a spray mister or a clean eye dropper.
Moss can loss color over time. In the wild moss gets nutrients from rainwater. If you don't use rainwater to occassionally spray your terrarium, you can use MaxSea 16/16/16 seaweed based plant food to provide nutrition for the moss. I sell this at shows or you can buy it at local garden centers. FYI...This is the only plant food I know of that is safe for moss, and only if used diluted as stated below! Other fertilizers will easily kill moss. Dilute the MaxSea with distilled water at 1/4 teaspoon per gallon of water. Spray lightly if the moss loses color, or no more than once a month. Avoid spraying the soil or gravel. You can spray slow-growing plants like fittonia but generally your terrarium does not need to be fertilized. I use worm castings as part of the substrate and that is usually enough to sustain the terrarium for a long time.
If you see small dark winged insects then you have fungus gnats in your terrarium. Fungus gnats are attracted to humidity so often appear around houseplants. If you leave your terrarium open for any time do it away from any infected houseplants. They are harmless thankfully, but can be annoying. They are attracted to fresh air so should rise upwards when you remove the terrarium lid. You could use a plastic bag to trap them, attach some sticky tape to the opening, or just squish them against the glass. If you kill the gnats as you see them, you should find they die off quite quickly. I have never seen them become a long term major problem in a terrarium. Avoid using any spray or insecticide, even if it is organic or "natural". Moss, delicate plants and springtails can easily be killed off by such treatments. If the fungus gnats stick around you can sprinkle crumbs of Mosquito Bits or Dunks onto the substrate and add it to the water. They contain a specific bacteria that kills fungus gnat larvae as well as moquito larvae. When you mist with water the bacteria is released into the soil.
Small sewing scissors work well to trim plants. Look for scissors that are 4" to 5" long with a roughly 2" blade. Scissors in the classic style (no rubber grip on handles) have thinner, more precise blades. Keep a look out for rust on the blades. Cleaning and drying well after use can help prevent rust. Store in a dry plac Wiping the blades with petroleum jelly (wipe off the excess) is a good extra step that won't harm the plants. I've heard nail clippers can be used too. I use electrical tweezers to pick up trimmed plant pieces. Tweezers roughly 6" to 7" long with a pointed tip work well. You can try regular tweezers if they are long enough.
Medium or Tall Terrariums
Aquarium scissors can be used to trim plants in most terrariums. Some versions have curved blades that make it easier to trim moss. Use aquarium tweezers to pick up trimmed plant pieces and to clean the walls with a piece of microfiber cloth. Aquarium tools are often carbon coated to prevent rust.
Surgical Scissors (Amazon) also work well but they are generally shorter in length.