Cat Grass Seeds

What is cat grass?

Cat grass is a general term for any fast-growing cereal grain grass grown in pots for cats to chew and eat. It is not a single plant species — the name refers to the growing purpose rather than a specific botanical identity.

The most common cat grass species sold and grown in the US:

All four are safe for cats and dogs according to the ASPCA’s plant toxicity database. All are cereal grains — the same crops grown for human food — and contain no compounds harmful to pets.

Cat grass is completely different from lawn grass. Lawn grass seed mixes contain species like Kentucky bluegrass, fescue, and bermudagrass that are not the same as cereal grains and are frequently treated with fungicide coatings. Do not substitute lawn grass seed for cat grass.

Why cats eat grass

Cats are obligate carnivores, yet they consistently seek out and eat grass — a behavior observed in wild cats worldwide. The exact reasons are not fully understood by veterinary science, but several functional theories have consistent support:

Digestive regulation: Grass provides insoluble fiber that moves through the digestive tract undigested. In cats that swallow fur while grooming, this fiber may help move material through the gut or trigger vomiting that clears hair accumulation.

Folic acid supplementation: Fresh grass contains folic acid (vitamin B9), which supports cell division and oxygen transport. A cat’s natural prey contains some folic acid; grass may supplement this when prey is scarce or in the case of indoor cats, absent.

Natural enrichment: Chewing grass appears to provide tactile and sensory stimulation. Indoor cats in particular, lacking the environmental complexity of outdoor life, may seek out grass as a form of behavioral enrichment.

Instinct: Some researchers believe grass eating is simply an inherited behavior from wild ancestors that persists regardless of whether the specific function is relevant in a domestic context.

Whatever the reason, most cats offered cat grass use it regularly. Providing indoor cat grass reduces the likelihood that your cat will target your other houseplants — many of which are toxic to cats. Our guide to plants toxic to cats and our article on plants cats might nibble and what’s safe cover the specific toxicity concerns for common houseplants. Our article on whether cats can eat spider plants addresses one of the most commonly nibbled houseplants.

Where to buy cat grass seeds

Cat grass seeds are sold in three main places in the US:

1. Pet stores and pet supply chains: Sell packaged cat grass kits or loose seed; typically wheatgrass or a mixed cereal blend; often more expensive per ounce than buying seed bulk.

2. Online seed retailers: Bulk seed for sprouting or cat grass at much lower cost per ounce; look for untreated seeds (no fungicide coating); wheatgrass and oat grass are the most commonly sold.

3. Health food stores or sprout seed suppliers: Wheatgrass seed for human juicing consumption is identical to cat grass; health food stores carry it in bulk at good prices; it is always untreated.

Always verify seeds are untreated. Treated seed (coated with fungicide to protect germinating crops) is labeled “treated” on the packaging and may list pesticide active ingredients. Treated seed is not safe for human sprouts or for cat grass. Untreated seed intended for sprouting or consumption is clearly labeled and is what you want.

Seed labels to look for: “sprouting seed,” “microgreens seed,” “untreated,” “food grade.” These designations indicate the seed has not been chemically treated.

Container selection

Cat grass grows in almost any shallow container with drainage holes. The container does not need to be deep — cereal grass roots stay in the top 3–4 inches of soil and do not require depth for good growth.

Good container choices:

• 6–8 inch nursery pots (inexpensive, stack easily)
• Shallow seedling trays with drainage holes (fit 2–3 plantings side by side)
• Terracotta dishes or small planters (attractive on a windowsill)
• Repurposed food containers with drainage holes punched in the bottom

Avoid containers without drainage. Cat grass watered in a container without drainage holes will develop mold at the soil surface within a few days — the most common reason cat grass fails before the cat gets to use it.

Potting mix for cat grass

Cat grass does not need special potting mix. Any standard all-purpose potting soil works well. The grass grows so quickly and is harvested (by the cat) within a few weeks, so nutrient content matters less than drainage and texture.

Good choices:

• Standard all-purpose potting mix
• Seed-starting mix (slightly lighter texture)
• Coco coir mixed with potting soil (excellent drainage and moisture retention)

Our best soil for indoor plants guide covers potting mix selection for indoor growing projects in more detail.

Fill the container to within half an inch of the top. Cat grass sown too shallowly in a deeply filled pot wastes space; the grass roots don’t need depth and filling high gives the cat easier access to the blades without tipping the container.

How to sow cat grass seeds

The sowing process is simple and takes less than five minutes.

1. Pre-soak seeds for 8–12 hours before planting. This is optional but speeds germination by 1–2 days. Place seeds in a small bowl of water, let soak overnight, then drain.

2. Fill the container to within ½ inch of the top with potting mix.

3. Sow seeds thickly — one seed every ¼ to ½ inch across the entire surface. Cat grass is meant to grow as a dense mat, not individual plants. Thin sowing creates sparse patches that cats ignore; dense sowing creates a lush mat they’ll return to repeatedly.

4. Press seeds gently into the soil surface with your palm. Seeds should be in contact with soil but not buried deeply — no more than ¼ inch of soil covering them, if any.

5. Water gently with a watering can or mister. The soil should be thoroughly moist but not dripping.

6. Cover the container with a clear plastic bag or humidity dome for the first 3–4 days. This maintains the consistent moisture needed for quick, even germination. Check once daily; remove the cover when you see green shoots breaking the soil surface.

7. Move to a bright location. A south- or east-facing windowsill works well. Supplemental grow light is not necessary but speeds growth if your windows are limited.

Growing conditions

Cat grass grows successfully at normal indoor temperatures — there is no need to adjust your thermostat or provide special conditions.

Water when the top ½ inch of soil feels dry. Cat grass wilts visibly when dry — this is not permanent damage, but consistent drought stress speeds up yellowing. Overwatering causes mold at the soil surface, not root rot; the fix is simply to water less frequently and ensure drainage holes work.

From seed to cat: the growth timeline

At the 10–14 day mark, simply set the container in front of your cat and let them investigate. Most cats discover it within minutes. Cats typically bite or pull at the grass, chewing off sections 1–2 inches long. The plant regrows from the cut point, which extends usable life somewhat.

Extending cat grass life

Individual containers of cat grass typically remain fresh for 2–4 weeks before yellowing progresses to the point where cats lose interest. Several techniques extend that window:

Cut back heavily grazed sections. When a cat flattens and heavily chews one area, the remaining short stems may yellow faster. Trimming the patch level with scissors encourages fresh regrowth from the same root mat.

Move to a brighter location as the grass ages. Older grass benefits from more light to sustain chlorophyll production. If your primary windowsill is moderate light, moving the aging container to a brighter spot adds a few days.

Avoid overwatering. As grass ages, it needs slightly less water than during the active growth phase. The most common cause of early yellowing in cat grass is continued frequent watering after the mat is fully established.

Setting up a rotation

The best long-term cat grass strategy is a staggered rotation of 3–4 containers, each started 10–12 days apart. When the oldest container yellows, you compost it and start a new one — the freshest container takes its place as the active one.

A simple rotation schedule:

• Container 1: Week 1 (just sprouted)
• Container 2: Week 2 (at peak)
• Container 3: Week 3 (older; still usable)
• Container 4: New this week (just seeded)

When container 3 is composted, container 4 moves to the active position and a new container 1 is seeded. The rotation is self-sustaining with one new seeding every 10–12 days.

Common problems

Mold on the soil surface: White or gray fuzzy mold appears in the first week, particularly under the humidity cover. Cause: poor air circulation combined with wet soil. Fix: remove the plastic cover earlier (at day 2–3), water slightly less, and improve airflow around the container. Surface mold does not harm the seeds but can spread to seedlings in very wet conditions.

Seeds not germinating: Most often the seeds are old (buy fresh seed for best results; cereal grain seed stays viable for 1–2 years stored cool and dry) or the soil was allowed to dry out during the first 3–5 days. Consistent moisture during germination is essential.

Yellowing before the cat uses it: Usually a light problem or the grass has outgrown the pot. Ensure at least 4 hours of bright light daily. Cat grass grown in low light goes yellow within 10–12 days regardless of watering.

Cat ignoring the grass: Some cats take a few days to investigate and accept a new item. Place the container where the cat frequents, not in an out-of-the-way location. Cats that have never had access to cat grass may take 1–2 weeks to begin using it regularly.

Cat grass vs. catnip and catmint

Cat grass, catnip, and catmint are three different plants frequently discussed in the context of cat-friendly gardening. They serve completely different purposes:

• Cat grass (wheatgrass, oat grass): Grown for cats to eat and chew; provides fiber and nutrients; calming, not stimulating
• Catnip (Nepeta cataria): Triggers a brief euphoric response in approximately 50–70% of cats through the compound nepetalactone; eaten or rolled in; stimulating
• Catmint (Nepeta spp.): Ornamental plants with mild catnip properties; less intense response than true catnip; useful as a garden perennial

See our catnip vs. catmint guide for a detailed comparison of those two plants, and our catmint care guide for growing catmint as a perennial in US gardens.

Cat grass complements both — it’s the functional, nutritional component while catnip and catmint provide enrichment and behavioral stimulation.

For gardeners interested in other fast indoor growing projects, our guide to growing herbs indoors covers basil, parsley, cilantro, and mint with similar setup requirements to cat grass — and for households without drainage-friendly windowsills, our guide to growing lavender indoors addresses the different needs of woody herbs in containers.

The ASPCA’s Animal Poison Control Center plant database is the authoritative US resource for verifying plant toxicity to cats and dogs — useful for checking any plant in your home where a cat might investigate.