Quick answer: A cat-safe terrarium combines two layers of protection: plants listed as non-toxic to cats by the ASPCA, and a closed or lidded vessel on a fixed shelf the cat cannot knock or reach into. In a townhouse sunroom, give the cat its own cork-topped perch nearby so it has a better place to sit than the glass.
Sunrooms are where plants thrive and where cats like to bask. Put the two together and you get a cat stepping across a terrarium shelf to reach the warmest spot, or batting at fern fronds behind open glass.
Making a terrarium safe is partly about what grows inside and partly about where it sits. This plan covers both, using cork tiles as a soft, grippy landing surface for the cat away from the glass.
Start a Cat-Safe Terrarium With Non-Toxic Plants
The safest terrarium is one that would cause no harm even if the cat reached it. The ASPCA's plant list includes a number of terrarium-friendly plants in its plants non-toxic to cats section. Always check the exact species, since common names are shared between unrelated plants.
| Plant | Scientific name | ASPCA listing | Terrarium notes |
|---|---|---|---|
| Boston fern | Nephrolepis exaltata bostoniensis | Non-toxic | Likes humidity, needs space |
| Nerve plant | Fittonia verschaffeltii | Non-toxic | Classic closed-terrarium plant |
| Polka dot plant | Hypoestes phyllostachya | Non-toxic | Bright leaves, trim often |
| Friendship plant | Pilea involucrata | Non-toxic | Low, spreading |
| Baby rubber plant | Peperomia obtusifolia | Non-toxic | Suits open terrariums |
| African violet | Saintpaulia spp. | Non-toxic | Flowers in bright light |
Non-toxic does not mean edible. Chewing plants can still upset a cat's stomach, so the second layer of protection still matters. Our cat-safe houseplants list for apartments has more options.
Plants to Leave Out Completely
Some popular terrarium and sunroom plants appear on the ASPCA toxic list, including devil's ivy (pothos, Epipremnum aureum) and Aloe vera. Leave these out of any home with a cat that climbs.
Lilies need special mention. The FDA warns that lilies in the true lily and daylily families are very dangerous for cats, and that the entire lily plant is toxic: the stem, leaves, flowers, pollen, and even the water in a vase. Even a small amount can cause kidney failure. Do not keep these in a sunroom a cat can enter, even in a closed case.
Our guide to swapping toxic plants for lookalikes suggests safe replacements, and holiday plants toxic to cats covers seasonal risks.
Choose a Closed or Lidded Vessel
- Closed glass cases with a fitted lid suit ferns, Fittonia and moss.
- Cabinet-style terrariums with a door that latches are harder to open than open bowls.
- Avoid open fishbowl shapes at cat height; paws fit straight in.
- Heavy, wide-based vessels tip less than tall narrow ones.
Closed terrariums also keep soil and stones inside. Loose decorative pebbles and moss can be batted out and chewed.
Fixing the Shelf So It Cannot Be Knocked
International Cat Care notes that cats like high places to sit, so assume a cat will try to reach any shelf. Wall-fix shelving units with anti-tip brackets into studs, and set the terrarium at the back of the shelf, not at the edge.
- Anchor the shelf unit to the wall.
- Put a strip of non-slip mat under the terrarium.
- Leave no gap between shelves wide enough for a cat to sit beside the glass.
- Keep the shelf away from furniture the cat uses as a launch point.
Cork Tile Landing Pads for the Cat
Rather than only blocking the cat, give it a better place to be. Cork tiles are light, warm underfoot and grippy. Glue two or three to the top of a low cabinet or wide windowsill on the opposite side of the sunroom, so the cat has a sunny perch that is clearly its own.
Add a folded blanket and a scratcher nearby. A cat with a warm perch, a scratch spot and a view has much less reason to climb the plant shelf. Our wall shelves and window perches DIY hub has more perch designs.
Building a Simple Terrarium Cabinet
If you cannot find a closed case the right size, a small glass-fronted cabinet makes a sturdy alternative. Many second-hand display cabinets have a door that closes with a magnetic catch; add a simple hook-and-eye latch higher up, where a paw cannot work it loose. Line the shelf inside with a plastic tray so water and soil stay contained.
Ventilation still matters for the plants. Leave the door ajar only while you are in the room, or drill a few small holes in the cabinet back near the top, too small for a claw. Condensation on the glass each morning is normal for a humid planting; if it never clears, open the door for an hour while you are home to let the air change.
Stand the cabinet on the floor or a low, wide plinth rather than on top of other furniture. A heavy cabinet at low height is far harder for a cat to topple than a light case set high on a shelf, and it keeps the plants away from the cat's preferred lookout points.
Before planting, rinse any decorative stones and moss and keep spare materials sealed in a cupboard. Small loose items left on a windowsill are exactly the kind of thing a curious cat bats onto the floor and chews.
Townhouse Layout Tips
Townhouses often have a sunroom at the back of the ground floor with the cat's routes running past it. Look at how the cat currently enters the room and where it heads.
- Keep the cat's perch near the sunroom door so it does not cross past the plants.
- Place the terrarium shelf along a wall the cat does not normally walk.
- Close the sunroom when you are out if the cat is a determined climber.
- Keep watering cans and plant food in a closed cupboard.
For broader ideas on combining plants and cats, see the cat-safe plants indoor garden hub, and for a room with the same materials, our toxic plant swap for a sunroom with cork tiles shows another layout.
Daily Habits That Keep the Glass Safe
Close the lid after misting and check it is seated. Wipe up any spilled water, since a damp shelf can make a cat slip. Trim fronds that push against the glass or poke out of the lid gap; moving leaves invite a paw.
If you add any new plant, check it on the ASPCA list by scientific name first. Keep a note of what is in each terrarium so you can tell a vet quickly if needed.
If Your Cat Gets Into the Terrarium
Remove the cat, take a photo of the plants and note what was chewed. If any part of a lily was involved, the FDA advises calling your veterinarian or a pet poison control centre immediately; with other plants, call your vet for advice, especially if you see drooling, vomiting or lethargy.
Then look at how the cat got there. Usually there is a launch point, such as a chair or a gap on the shelf, that can be moved or closed.
Terrarium Safety Checklist
- Use plants listed non-toxic by the ASPCA.
- Leave out lilies, pothos and aloe.
- Choose a lidded or latched vessel.
- Anchor the shelf and place the glass at the back.
- Give the cat a cork-topped perch elsewhere.
- Trim leaves that poke out.
- Know what is planted in case of an accident.
Terrarium and Cats FAQ
Which terrarium plants are safe for cats?
Several common terrarium plants appear on the ASPCA's non-toxic list, including Boston fern, nerve plant (Fittonia verschaffeltii), polka dot plant, friendship plant (Pilea involucrata), baby rubber plant and African violet. Check the scientific name before buying, because common names are shared, and remember chewing can still cause mild stomach upset.
Can I keep lilies in a closed terrarium if I have a cat?
It is best not to. The FDA says every part of true lilies and daylilies is toxic to cats, including the pollen and vase water, and a small amount can cause kidney failure. Pollen can escape when you open the case, so keep these lilies out of a cat home entirely.
How do I stop my cat climbing the plant shelf?
Anchor the shelf, remove nearby launch points such as chairs and leave no space beside the glass for a cat to sit. Then give the cat a sunny, cork-topped perch elsewhere in the room with a blanket and a scratcher, so it has a better place to settle than the shelf.
What should I do if my cat chews a terrarium plant?
Remove the cat, photograph the plant and note how much was eaten. If a lily was involved, call your vet or a pet poison control centre straight away, as the FDA advises. For other plants, call your vet for advice, especially if you notice drooling, vomiting or lethargy.
