A quick care guide for our Classic Terrariums.

These minimalist designs typically feature pin cushion moss, with many also including a small fern nestled among rocks or driftwood. They’re easy to care for and accessible to anyone, even if you don’t think of yourself as having a green thumb.

This short guide covers the two main essentials—light and water—and also includes quick tips on placement and maintenance. It’s designed to help you keep everything thriving with minimal effort and a few easy routines.

Light

Terrarium lighting is one of the most important factors in keeping your plants healthy over time. Most terrarium plants, especially mosses and ferns, evolved to grow in dappled shade on the forest floor, where they receive bright, filtered light.

To mimic that indoors, one option is to place your terrarium near a bright window but out of direct sun. Short periods of sun may be okay, especially in the morning, but be cautious. Too much can cause overheating, drying, or scorching, and you may need to mist more often to compensate.

The brighter the light the better, as long as it’s indirect. Avoid placing your terrarium in direct sun, which can heat the glass and dry out the plants.

If natural light is limited, a small LED grow light on a timer can provide consistent, gentle light each day. I usually prefer this method, as it lets you keep your terrarium on a desk or shelf away from windows, and you know it's getting proper light year round. Aim for 8 to 12 hours of light per day.

Crisp moss or wilting ferns may indicate too much heat or sun, or possibly not enough water. Watch your other plants for pale or stretched-out growth as a sign of too little light. When the lighting is right, your terrarium should stay green, compact, and thriving with very little effort.

Water

Watering a terrarium isn’t about following a strict schedule. It’s about reading the environment and responding to what you see. In open-top terrariums like our classic designs, moisture consistently evaporates, so regular misting helps keep the moss soft, green, and healthy.

We chose pin cushion moss specifically for its durability. It holds up well in open-air conditions and can even bounce back after drying out, which makes it especially forgiving for beginners or busy owners.

Use a fine spray bottle to mist the moss lightly a few times a week—just enough to rehydrate without soaking. You can also place a loose-fitting cover over the top to slow down evaporation and reduce how often you need to mist. I’m happy to recommend lid options if you’re interested.

If your terrarium includes a fern, it may need a little extra care. Add a small amount of water once a week directly at the base of the plant using a squeeze bottle or the tip of your mister. This helps keep the roots hydrated without oversaturating the surrounding moss.

You’ll quickly learn to read what your terrarium needs with a glance or a gentle touch. If the moss feels dry or stiff, it’s time to mist. Pin cushion moss also tends to fade or lose its vibrant color when it’s too dry. If it feels cool, springy, and green, you’re in a good place.

Avoid overwatering. Standing water or soggy soil can lead to mold, rot, or decline. The substrate should stay lightly moist but never appear wet or waterlogged. Gentle, consistent care keeps the balance just right.

Placement

Where you place your terrarium plays a big role in how well it does over time.

Moss and ferns prefer a calm, stable environment with consistent indoor temperatures and minimal airflow. Room temperature is ideal—anywhere between 60 and 80°F—and the more consistent the conditions, the better.

A bright room is perfect, as long as the container isn’t sitting in direct sunlight. Desks, shelves, or tabletops a few feet from a window usually work well. As mentioned earlier, terrariums can also thrive in darker areas if you use a grow light.

If placing your terrarium on a windowsill, east- and north-facing windows are generally best. West- and south-facing windows can work too, but be cautious, they often get stronger sun that may be too intense for moss and ferns.

Try to keep your terrarium away from heating vents, air conditioners, or drafty windows. If that’s your only option, just know you may need to mist more often to keep up with the dry air.

Maintenance

Terrarium maintenance is remarkably simple. Pin cushion moss grows slowly and often won’t need trimming or reshaping for years. In many cases, your terrarium can go months without any real maintenance at all, especially if the conditions are right.

If your terrarium includes a fern, occasional trimming can help keep it neat and prevent overcrowding. Snip back any fronds that are getting too tall or reaching beyond the space. You can also remove any parts of the fern that aren’t thriving to encourage healthy new growth.

There’s no need to fertilize. Both moss and ferns are adapted to nutrient-poor environments and will do just fine with light and moisture alone.

Beyond that, it’s mostly about wiping the glass if it gets dusty or smudged. With just a few minutes of attention now and then, your terrarium will stay vibrant, balanced, and beautiful for a long time.

Have questions?

Every space is different, and your terrarium will find its own rhythm in your home. If anything looks off or you’re not sure what you’re seeing, feel free to reach out with a photo. I’m always happy to help.

Enjoy the calm and curiosity your new terrarium brings.