How to Grow Wheatgrass for Cats

By the Countertop Harvest team · Last updated October 20, 2026 · How we choose products

A pot of wheatgrass gives an indoor cat something safe and green to chew. Veterinarians at VCA Animal Hospitals explain that "cat grass" usually means cereal grasses such as oat, wheat, barley and rye (VCA), and Texas A&M's College of Veterinary Medicine describes it as a source of environmental enrichment, especially for indoor cats (Texas A&M Vet Med). VCA says it is ready to eat in 10 to 14 days (VCA). This guide covers what the vets say about cat grass, how to grow it, and how much is sensible.

Why cats eat grass, and whether they need it

No one knows for sure why cats eat grass. Dr. Lori Teller at Texas A&M says veterinarians haven't agreed on one answer; one theory is that it is fiber that acts as a mild laxative or triggers vomiting (Texas A&M Vet Med). VCA describes a similar theory, that wild cats may have eaten grass to bring up hair, bones or feathers from their prey (VCA).

Cat grass isn't essential. Dr. Teller says it is not a required part of a cat's diet if the food is well balanced, though many cats enjoy it and it may provide some vitamins A and D (Texas A&M Vet Med). VCA adds that grass provides roughage that can help digestion (VCA). We think of it as a treat and a bit of enrichment rather than a supplement.

How much is too much

VCA's advice is moderation. Cats lack the enzymes to digest large amounts of grass, so overeating can cause vomiting, and if the cat doesn't vomit, the fiber could build up and cause an intestinal blockage (VCA). VCA's rule of thumb is that treats of any kind, grass included, should make up no more than 10% of a cat's total calories (VCA). Dr. Teller adds that if a cat eats grass voraciously, it may be worth asking a veterinarian whether its diet is meeting its needs (Texas A&M Vet Med).

How to grow wheatgrass for a cat

VCA's step-by-step method is simple, and it works for wheat, oats or a mix (VCA).

1. Pick a shallow, heavy container with drainage. VCA prefers a heavier pot because it is less likely to tip when a cat paws at it or tries to walk on it (VCA).
2. Fill it about three-quarters full of regular potting soil (VCA).
3. Sow thickly. Sprinkle seeds evenly over the surface, cover them with ¼ inch of soil and water with a spray bottle (VCA).
4. Cover until they sprout. VCA covers the pot loosely with plastic wrap and keeps it at room temperature, out of direct sun, until sprouts appear in 3 to 7 days (VCA). Keep the seeds constantly damp for those first days (VCA).
5. Move it to the light. Once the seeds sprout, remove the wrap and move the pot somewhere with direct sun (VCA).
6. Water sparingly. VCA keeps the soil damp but not wet, because too much water can cause mold, and re-waters when the surface feels dry (VCA).

Some growers soak the seed first. VCA says many gardeners plant straight from the packet (VCA), while Botanical Interests suggests soaking its wheatgrass seed for 12 to 24 hours to speed germination (Botanical Interests, wheatgrass).

When to offer it and how long it lasts

VCA says the grass should be ready in 10 to 14 days, or when it is about 4 inches tall, and that a pot should last up to three weeks (VCA). When blades wilt or yellow, pull out the old shoots and sow again (VCA). For a steady supply, VCA plants several pots about a week apart and rotates them (VCA). We set the pot down for a supervised nibble and then put it back up on a shelf, which keeps the grass from being flattened.

Which seeds to use

Wheatgrass seed is hard red winter wheat (Triticum aestivum), according to Botanical Interests (Botanical Interests, wheatgrass). Its cat grass seed is oats (Avena sativa), with germination in 3 to 8 days and 10 to 15 days to maturity (Botanical Interests, cat grass). Either works; VCA suggests trying one or two kinds and seeing which your cat prefers (VCA). If you'd like seeds, here are Botanical Interests' wheatgrass seeds and oat cat grass seeds.

Cat grass isn't catnip. VCA points out that catnip is a member of the mint family (VCA).

Plants to keep away from cats

Dr. Teller notes that homegrown cat grass is safer than grass outdoors, which may have been exposed to chemicals or contaminated water, and that the bigger concern is a cat confusing cat grass with a toxic plant (Texas A&M Vet Med). A few to know:

• Lilies. K-State Extension warns that even a very small amount of a true lily or daylily, such as a piece of leaf, petal or pollen, can be life-threatening to a cat and needs immediate veterinary care (K-State Extension).
• Lemongrass. It looks like grass, but the ASPCA lists lemon grass as toxic to cats, with stomach upset as the sign (ASPCA, Lemon grass). See our lemongrass guide.
• Other houseplants. K-State notes that common houseplants containing calcium oxalates, such as dumb cane, can cause drooling, mouth irritation and stomach upset (K-State Extension). The ASPCA keeps a full list of plants that are toxic and non-toxic to cats (ASPCA).

If you think your cat has eaten a toxic plant, the ASPCA asks you to call its Animal Poison Control Center at (888) 426-4435 or your veterinarian; a fee may apply (ASPCA, Lemon grass).

Common problems

Mold on the soil

Too much water. VCA warns that overwatering can cause mold and ruin the crop (VCA). Let the surface dry before watering again.

Thin, pale grass

It needs more light. VCA moves sprouted grass into direct sun (VCA).

Cat knocks the pot over

Use a heavier, shallow container, as VCA suggests (VCA).

More quick crops: sprouts in a jar and microgreens. You can also find a guide by plant.

Sources

• VCA Animal Hospitals (Malcolm Weir, DVM, and Lynn Buzhardt, DVM): Where the green grass grows, grass treats for cats
• Texas A&M College of Veterinary Medicine & Biomedical Sciences, Pet Talk: The basics of cat grass (2019)
• K-State Research and Extension, Douglas County: Plants and pets don't always mix
• ASPCA Animal Poison Control Center: Toxic and non-toxic plant list, cats
• ASPCA Animal Poison Control Center: Lemon grass
• Botanical Interests product page: Wheatgrass juice seeds (Triticum aestivum)
• Botanical Interests product page: Cat grass seeds (Avena sativa)

All sources accessed October 20, 2026. This guide is general information and is not veterinary advice. Ask your veterinarian about your own cat.

Frequently asked questions

Is wheatgrass safe for cats?

Cat grass, which includes wheat, oat, barley and rye grasses, is offered by many cat owners. VCA veterinarians recommend moderation, because overeating can cause vomiting and, rarely, a blockage. Keep treats including grass to no more than 10% of calories.

How long does cat grass take to grow?

VCA says sprouts appear in 3 to 7 days and the grass is ready in 10 to 14 days, or at about 4 inches tall. A pot lasts up to three weeks.

Do cats need cat grass?

No. Texas A&M veterinarian Dr. Lori Teller says it isn't required if the cat's diet is balanced, but many cats enjoy it and it can be enrichment for indoor cats.

Is wheatgrass the same as catnip?

No. VCA notes that catnip is a member of the mint family, while cat grass is a cereal grass such as wheat or oats.

Why does my cat throw up after eating grass?

VCA explains that cats can't digest large amounts of grass, so eating a lot can cause vomiting. Offer small amounts, and ask your vet if your cat eats grass voraciously.