Unlike dogs, which are omnivores which are able to consume both meat and plant materials (including your garden vegetables!), cats are obligate carnivores or ‘true carnivores’, meaning that they rely almost entirely on a diet of animal proteins to obtain their nutrition.
Cats may lack the digestive system structure and the various enzymes needed to be able to digest plant material and absorb nutrients efficiently, but they don’t mind the occasional nibble of some plants that they find attractive to them from time to time!
Indoor and Outdoor Cats and Access to Edible Plants
When cats venture outdoors, they have available to them a wide choice of plants to nibble on, often to help them with their digestion, and since they’re very particular, they know what’s edible to them and what isn’t.
Indoor cats, on the other hand, may not have access to any plants at all, or may only have access to indoor plants (houseplants), many of which are toxic to them, and to dogs also!
The types of plants grown as houseplants are typically tropical and subtropical understory plants that are native to hot, humid climates, growing close to ground level, under the shade of dense forest canopies. To avoid being eaten in a forest filled with wildlife, these plants contain irritant or toxic compounds to discourage herbivores. Many contain compounds such as raphides (needle-shaped calcium oxalate crystals), solouble oxalates, irritant latex sap or other means of discouraging predation.
That said, the existence of natural plant defenses is definitely NOT a reason to clear the house of indoor plants, as most plant have some kind of defense mechanism, otherwise they would be what we call ‘edible plants’, and we would eat them too!
To keep indoor kitties happy, we can grow them some plants to munch on, so they leave our houseplants alone. Outdoor cats will also enjoy having their preferred herbs growing in the garden too, so they can indulge themselves as they choose.
In this article, we’ll look at the best herbs to grow for cats, and how to care for those plants whether we’re growing them in pots or in the garden.
The Four Best Herbs for Cats and How to Grow Them
Catnip, catmint, cat thyme, and cat grass are very popular herbs with cats, and each with its own unique qualities and benefits.
Catnip (Nepeta cataria) is an upright herbaceous perennial plant from the Lamiaceae (mint) family, with soft, aromatic, musky-scented grey-green leaves, that’s native to Europe, Southwestern, and Central Asia. It grows into a clump around 60-90 cm (24-36”) tall and wide, with, dense spikes of small white flowers from late spring to early autumn that are very attractive to bees.
Growing – This herb will grow in full sun to part shade, and prefers moist, well-drained moderately fertile soils. This low-maintenance plant thrives in dry soils and is highly drought tolerant. It dislikes conditions that are wet and humid, so it won’t grow in tropical climates. If space is an issue, or in locations where frosts occur, catnip may be successfully grown in pots.
It’s easy to maintain catnip as it has no serious pest or disease problems. Keep snails and slugs away from young plants. Trim the plant after flowering by cutting it back in height to keep it compact and encourage it to grow bushier.
Propagation – If catnip is allowed to finish flowering, it will self-sow very easily from the tiny seeds it produces and will reappear each year on its own in the garden.
- The seeds can also be collected to propagate it. Sow the seeds in seed trays in early spring and then plant them out when the weather warms up.
- It’s possible to propagate catnip by dividing mature clumps in late winter to early spring, before new growth starts to emerge, or in early autumn, which allows plants to establish their roots before winter arrives.
- Propagation can also be carried out using softwood cuttings in early summer, or semi-ripe cuttings in early autumn.
Effect on cats – The herb catnip is well-known for its ability to attract cats and stimulate playful behaviour. The active compound in catnip that affects cats is nepetalactone, which acts as a stimulant, and this is found in the leaves, stems, and seeds of catnip plants.
Although some cats don’t really respond to catnip, others absolutely love it, they will roll around in the plant, rubbing against it, purring, getting generally excited, licking and eating it. After that they usually just settle, chill out and relax due to the mild sedative effect.
It’s estimated that around two-thirds of cats respond to catnip. Whether cats respond to catnip is an inherited trait, based on having specific genes that produce a sensitivity to the compound nepetalactone. When cats brush against catnip leaves, or bruise them, the chemical compounds which they respond to are released. If cats get too excited, it may be necessary to protect your plants! Even big cats, such as lions, may respond to catnip, but not so enthusiastically as domestic cats thankfully!
The ones that are unaffected include cats that are younger than six months, and those whose genetics originate from areas where catnip doesn’t natively grow.
Cat toys can be made by stuffing fresh whole catnip leaves or dry leaves into small cloth bags that are sewn shut. Cloth works well because it allows the herbal aroma to permeate though so cats can smell it.
To dry catnip leaves, prune off branches hang them upside-down indoors in the shade, away from direst sun. Once dry, strip off the leaves, place them in an airtight jar and keep in a cool dark place.
Other uses – Catnip has insect-repellent properties, and can be used for keeping certain insects away, including mosquitoes and cockroaches.
It’s also used traditionally as a mildly relaxing medicinal tea mild and relaxant effects. The active constituents nepetalactone has a similar structure to the valepotriates, a group of chemical compounds found in the roots of the valerian (Valeriana officinalis) plant, which has sedative and anxiolytic (anti-anxiety) properties and has been used for centuries as a natural remedy for promoting relaxation and improving sleep quality. Knowing this, it’s no coincidence that cats also respond to valerian root in a similar way that they do to catnip.
Catmint (Nepeta mussinii) is a compact spreading perennial groundcover plant from the Lamiaceae (mint) family that grows around 40cm tall and wide. It has grey-green foliage and produced blue flowers in the warmer seasons. It grows in full sun to part shade in well-drained soils and is drought tolerant.
This plant is closely related to catnip, being of the same genus, but has smaller and finer leaves which make it easy to distinguish. Catmint also contains nepetalactone, so it’s also attractive to cats, but usually has a milder effect compared to catnip.
Some cats may show interest in catmint and react in the same way, while others may have a more subdued response or not respond at all. It’s worth pointing out that individual cats may have different preferences and reactions to different plants. Some cats may strongly respond to both catnip and catmint, while others may show a preference for one over the other. For this reason, it’s a good idea to offer both catnip and catmint to cats to determine which they prefer.
3. Cat Thyme
Cat thyme (Teucrium marum) is a small, low growing, spreading perennial plant from the Lamiaceae (mint) family, with dense, tiny silver-blue-grey leaves, that’s native to Sapin and the Western Mediterranean region.
This plant typically grows to around 30cm (12”) tall and 45cm (18”) wide but will get larger than that under ideal conditions. It produces lots of attractive small magenta-pink flowers in summer which are attractive to bees and other pollinators.
Even though cat thyme is a type of plant known as germander, and not a variety of thyme, is does bear some resemblance to a thyme herb in its form and appearance.
Growing – This herb prefers a well-drained, moist or dry humus rich soil in a full sun position and will not grow in shade. It’s very hardy and drought-tolerant once established and will grow in windy locations.
Caring for cat thyme is quite straightforward, prune the plant back by 1/3rd after flowering to maintain a tidy growth habit, to encourage the plant to grow bushier, and to stop the plant getting too woody. Give the plant a little general-purpose fertiliser in spring to promote new growth.
Mulching the soil around the plant in extremely hot weather helps keep the roots cool. The plant may be able to survive frosts, but covering the plant when frosts are expected may help protect it.
Most pests aren’t too interested in this aromatic herb, rabbits and deer even leave it alone!
Propagation – Cat thyme may be propagated by division or by taking semi-hardwood cuttings in spring. It can also be grown from seed, sow seeds in spring.
Effect on cats – The aromatic leaves of cat thyme have a unique minty/camphor-like odour, and contains various volatile oils, including thymol, which is also happens to be found in in thyme oil, and thought to be the main compound responsible for its appeal to cats.
Cat thyme acts as a stimulant for cats and they respond to it in a similar way as they do to catnip, but its effects can vary between cats. Cats can get very excited about cat thyme, and rub against it, or even roll around on top of the plant when it’s growing in the garden, which can destroy a plant fairly quickly or make it look a little messy! It survives excessive cat attention much better in pots.
Even though cats are generally very fond of nibbling at this herb, what’s surprising is that the leaves have a somewhat initial bitter taste, which then becomes more strongly peppery with a slight sensation of heat, which isn’t really a flavour we would expect cats to enjoy.
4. Cat Grass
Cat grass (Dactylis glomerata), also known as Cocksfoot, is a dense, cool-season perennial clumping grass from the Poaceae (grasses) family, and is native to Europe, temperate Asia and North Africa.
This deep-rooted, long-lived, mat-forming grass grows to a height of 60-150 cm (2′-5′) and its leaf blades are 30-60 cm (12-24”) long and 5-10 mm (3/16-3/8”) wide.
It produces a continuous growth of young leaves that can withstand heavy grazing, and is used agriculturally for silage, hay and pasture. I can provide forage for livestock, deer, geese, and rabbits. The dense network of non-rhizomatous roots makes it useful for erosion control on cut-down forest land and on slopes.
Growing – Cat grass prefers full sun, and moist, well-drained, rich or moderately fertile soils with an adequate water, but can tolerate shade, high temperatures and drought. It grows best in locations with day-temperatures ranging from 4.3°C – 23.8°C (40°F – 75°F), in temperate and sub-tropical regions, and even though it can grow in the tropics, it dislikes excessive humidity.
This tough grass is easy to maintain and doesn’t really have any diseases or insect problems.
Keep in mind that cat grass it is considered a weed in turf grass (lawns), but if you get any growing in a lawn, it’s easy to identify as it’s faster growing and stands well above a mown lawn in height, and it’s really easy to dig out the clump and transplant it to another location or into a pot.
Propagation – This grass is normally propagated from seed, but does not produce seed in the tropics, so seed can be purchased for the purpose.
It can also be propagated from slips; these are individual plants that are separated from the side of the main clump and transplanted elsewhere, and this is best done in early spring.
How to grow cat grass from seed
- Fill a seedling tray with premium potting mix and water it gently to moisten it.
- Sprinkle the seeds on the surface and cover them very lightly with a fine layer of potting mix.
- Cover the seedling tray with cling wrap or a plastic bag to retain the humidity and allow light in, but punch a few holes for ventilation.
- Place in a location that is not exposed to harsh direct sunlight and is at room temperature, and make sure to keep the potting mix moist by gently misting it with a spray bottle if it begins to dry out.
- When the seedlings emerge (in around 3 weeks), remove the plastic bag or cling wrap cover, and place in a protected sunny position that’s not too windy, exposed and hot.
- After the seedlings grow to around 10cm high, transplant into a larger pot.
When the cat grass grows to around 15cm high, it can be introduced to pet cats for eating.
Benefits to cats – Cat grass is named as such because cats are attracted to it and love to chew it. It’s a healthy treat that’s primarily used as a dietary supplement to aid digestion, help eliminate hairballs, and provide essential nutrients.
It provides numerous health benefits by adding many essential nutrients to a cat’s diet, as it contains vitamins A, B & D, folic acid (vitamin B9), niacin (vitamin B3), fibre, and the green plant pigment chlorophyll.
There’s an old myth that cats only eat grass when they’re sick, but that’s not the case. They enjoy eating various grasses, including barley grass, wheatgrass, and oat grass, which are safe for cats to consume. The exact compounds in cat grass that make it appealing to cats are not well understood, but taste might be a key factor.
Grasses help their digestive system and the fibre, which they can’t digest, helps them push out hairballs that they’ve swallowed when grooming themselves.
Unlike many of the other cat herbs which require full sun, cat grass tolerates shade, and grows reasonably well, albeit more slowly, when kept inside near a bright, sunny window. This makes it a handy plant to have available for indoor cats, who don’t have access to any grass to chew when their tummies are upset.
How to Grow Cat Herbs in Pots
It’s best to grow cat herbs in low, wide, heavy stable pots such as terracotta squat pots to prevent the container tipping over when cats bite and pull at the plants or rub against them.
This is important when pots of cat herbs are brought inside the house for indoor cats. Tall, light plastic pots are easily knocked over, spilling plenty pf potting mix on the floor, which can get really messy, especially if the plant was just watered!
Use a premium grade potting mix, add slow-release fertiliser to the pots in spring to keep them growing through summer, and water them regularly when the weather is hot or windy.
Don’t sit the pots in saucers of water, as this can cause the roots to rot, especially in cold, wet weather. In the warmer seasons, if the pots have pot saucers or drip trays under them that catch the water, the excess water after watering should dry out after an hour or two, if it doesn’t, pour the water out from the pot saucer/drip tray.
Why You Should Grow Two Pots of Each Herb for Indoor Cats
Most herbs require a fair amount of sunlight to grow and develop their aromatic oils, and because most cat herbs are full sun plants, they should receive at least 6-8 hours of direct outdoor sunlight.
The light indoors is far less intense, but our eyes adjust to the reduced light intensity by dilating our pupils to let more light into our eyes to allow us to see clearly, making it seem much brighter in the house than it really is. Don’t be fooled thinking there’s enough light inside!
If pots of cat herbs are kept indoors, their growth will slow, and they will gradually decline from lack of light. All plants require sufficient light for photosynthesis, the process where the energy from sunlight is converted to chemical energy by forming sugars from carbon dioxide (CO2) in the air and water from the soil.
To avoid this problem, we can grow two pots of each cat herb. This way, one pot can come indoors for two or three days for the cats to munch on, while the other is outside. Then they’re swapped over, giving the plant a chance to recover and replenish its energy in full sunlight.
When pots of cat herbs are kept indoors, it’s best to sit them close to a bright, sunny window that receives midday or afternoon sun to maintain plant health. Keep the pots at least 30cm (12″) form the glass, don’t ever put them right against the windowpane, as plants will get burnt as there is lots of heat build-up and a lack of air circulation near the glass when the sun is shining.
Having two pots of a cat herb also provides more for cats to eat and prevents the plants from being nibbled back too hard. If plants are reduced by more than half their size, it can seriously weaken them, so if they’re ever eaten back hard like that, place them back outside to allow them to regrow and regain their strength and vigour!
As a final note, it’s worth mentioning that the effects of the cat stimulant herbs, catnip, catmint and cat thyme, are temporary and wear off after a short period, and cats don’t get addicted to them either!