Advice · 4 min read · Updated 6 November 2026
Cat-safe plants for a catio: what to grow and what to avoid (UK)
Why planting matters in a catio
A bare mesh box keeps a cat safe but does not give it much to do. Plants add scent, shade, places to hide and something to chew, which is especially important for cats that spend most of their time indoors. The catch is that cats in an enclosure cannot wander off to find something better, so anything you put in reach will get sniffed, brushed against and often nibbled.
That means plant choice is a safety decision, not just a style one. Plants outside the mesh can matter too, because pollen and leaves blow in and climbers grow through.
Plants that are generally considered safe
| Plant | Why cats like it | Growing notes |
|---|---|---|
| Cat grass (oat, wheat or barley) | Chewing aid, may help with hairballs | Sow in pots every few weeks for a steady supply |
| Catnip (Nepeta cataria) | Strong scent, rolling and play | Hardy perennial, gets flattened so grow spares |
| Catmint (Nepeta x faassenii) | Milder scent, flowers for bees | Tough, drought tolerant, good in troughs |
| Valerian | Scent many cats love | Tall, best in a deep pot or bed |
| Silver vine | Alternative for cats unmoved by catnip | Usually bought as dried sticks or a climber |
| Spider plant | Dangling leaves to bat | Better in covered or sheltered catios |
| Thyme, lemon balm, rosemary | Texture and scent | Low and bushy, useful edging plants |
Even safe plants can cause mild stomach upset if eaten in quantity, so watch new additions for the first few weeks.
Plants to keep out of and away from the catio
- All true lilies and day lilies, including the pollen and vase water, which can cause kidney failure
- Lily of the valley
- Foxglove
- Daffodil, tulip and hyacinth, especially the bulbs
- Yew, including clippings
- Ivy and English ivy climbing up the mesh
- Rhododendron and azalea
- Oleander and cherry laurel
- Autumn crocus
Lilies deserve particular attention. Only a small amount of pollen groomed off a cat's fur can be dangerous, so it is safest not to grow them anywhere the cat can reach, including just outside the mesh or in cut flowers on a windowsill next to the cat flap.
How to lay out a planted catio
Keep most plants at the edges in sturdy, heavy pots or troughs that cannot be knocked over. Raised planters work well because they double as a lookout. Leave a clear walkway and open floor so the cat is not forced to push through foliage to reach its shelf or bed.
Plant a sacrificial pot of cat grass and accept it will be grazed down. Rotating two or three pots, with one recovering in the house or greenhouse, keeps the enclosure green year round.
Soil, compost and garden chemicals
Cats will dig, so use peat-free compost without added fertiliser pellets or slug bait in any container inside the enclosure. Cocoa shell mulch is best avoided, as it contains the same compounds as chocolate. Do not use slug pellets, weedkiller or insecticide in or right next to the catio, and keep treated lawn areas outside the mesh until the product has fully dried.
If you use a tray of soil or sand as a digging spot, expect it to be used as a toilet and clean it like a litter tray.
Checklist before adding any new plant
- Check the full botanical name, not just the common name
- Look it up on a reputable pet poison list or ask your vet
- Check what is growing just outside the mesh as well
- Remove fallen flowers, berries and bulbs promptly
- Pot it in something heavy enough not to tip
- Watch the cat with it for the first few days
Garden centre labels rarely mention pets, and common names can be misleading. Several unrelated plants are sold as some kind of lily, for example, and catmint and catnip are different species with different strengths of scent. The botanical name on the label is the reliable way to check.
Seasonal planting through the year
A catio can stay green all year with a little planning. In spring, sow fresh trays of cat grass and divide catmint so you have spare plants ready to swap in when the originals get flattened. Spring is also when bulbs are at their most tempting, so make sure neighbouring borders do not have daffodils or tulips growing right up against the mesh.
In summer, herbs such as thyme and lemon balm grow fast and release scent in the heat, and taller valerian gives shade at floor level. Water pots in the evening so the compost is not soggy when the cat wants to lie on it in the morning.
Autumn is the time to clear fallen leaves and berries, especially from yew, holly and cotoneaster hedges near the enclosure. In winter, bring a pot of cat grass indoors to keep it growing, and use evergreen, cat-safe grasses or bare branches for texture outside. Avoid bringing seasonal plants such as lilies, poinsettia or mistletoe into rooms next to the cat flap over Christmas.
Frequently asked questions
What should I do if my cat chews a lily?
Treat it as an emergency and contact your vet straight away, even if the cat seems well. Lily poisoning can cause kidney damage that is only treatable if caught early, and signs such as vomiting or lethargy may not appear for some hours. Take a photo or a piece of the plant so the vet knows exactly what was eaten.
Is catnip safe for every cat?
Catnip is not considered toxic and many cats enjoy it, but not all cats react to it, and kittens often show no interest until they are a few months old. A few cats become over-excited, so give it in moderation. Eating a lot can cause a mild upset stomach, which usually passes on its own.
Can I grow climbers on the outside of the mesh?
You can, but choose a non-toxic climber and keep it trimmed so stems do not push through or loosen the mesh. Avoid ivy, wisteria and clematis next to a catio, as cats may chew leaves that grow through. Climbers also add weight and hold moisture against timber, so check fixings and posts more often.
plants toxic plants lilies catio design
Related services
We cover 250 towns and cities, including Peterborough, Bristol, Bath, Birmingham, Coventry, Nottingham.
