cats and cat grass

I’ve started growing cat grass for my kitten. It took some experimentation, but I was eventually able to come up with a method I’m happy with. I grow it a squat 8-oz mason jar with a frog lid screwed on it. It doesn’t require soil or a grow medium.

The instructions are as follows (UPDATE: see cat and cat grass 3.0 for the most recently updated variation of these instructions):

Grow Cat Grass!


  • cat grass seeds
  • water
  • measuring teaspoon
  • spoon or chopstick
  • 16-oz wide-mouth mason jar
  • 8-oz wide-mouth mason jar
  • canning lid for wide-mouth mason jar
  • mesh sprouting screen for wide-mouth mason jar
  • rust-proof frog lid for wide-mouth mason jar (can omit if your cat only nibbles on the grass; see Day 3 for explanation)
  • spray bottle
  • bowl to set tipped mason jar in


Day 0

On the morning of Day 0, measure out two (2) teaspoons of cat grass seeds and place in the 16-oz mason jar.

Add enough water so the seeds are completely submerged.

Allow the seeds to soak 8-12 hours. I put the canning lid on top of the jar with a gap in it for air flow. I doubt I really needed to use the lid at this point, but did so with the idea of preventing air-born contamination.

Note: I am following a standard seed-sprouting method. Soaking the seeds starts the germination process.

On the evening of Day 0 (12 hours), screw the mesh sprouting screen on the mason jar and drain the water out.

Rinse the seeds with another dousing of water, swirling the seeds about. Drain. Repeat 1-2 times. The reason for the extra rinsing is to clear away any mold spores and other contaminants.

Set the mason jar tipped at an angle in a bowl to allow residual water to drain. The reason for this is to try and prevent rotting and mold growth.

Place it away from a window.

Note: some sprouting instructions direct you to place the draining jars in total darkness, e.g., in a cupboard, to encourage sprouting. Other seed-sprouting sources say it’s unnecessary and are against placing the jars in enclosed spaces due to lack of air flow; their reasoning is that lack of air flow increases potential for mold growth. I found that leaving the jar on the kitchen counter, away from a window, works fine.

Day 1

On the morning (24 hours) and evening (36 hours) of Day 1, rinse and drain.

Day 2

By the morning of Day 2 (48 hours), I typically see actual grass shoots beginning to form. Proceed with the following steps if you see the beginnings of grass shoots. Otherwise, wait until the evening of Day 2 and reassess.

After rinsing the sprouted seeds, transfer them to the shallower 8-oz mason jar, spreading the seeds out on the bottom using a spoon or chopstick.

The reason I sprouted the seeds using the 16-oz jar is because the 8-oz jar is too small and squat to allow for rinsing and draining. I prefer the 8-oz size as the final container because its shape and size prevent it from being tipped over when my kitten is munching on the grass. It also allows for improved air flow so mold is less likely to develop.

Let the 8-oz jar with germinating seeds sit upright on the counter away from the window, and use the canning lid to cover the jar, leaving a gap. This allows for air flow to try and stave off mold, but also decreases the rate of moisture evaporation so the seeds don’t dry out completely.

Note: some methods of growing cat grass involve using either soil or “soil-less” grow mediums like coconut coir by now, and/or containers with drainage holes. I’ve found that the grass grows fine with water, alone. I like how clean and simple the water-only method is. I would have preferred a built-in drainage system, but couldn’t come up with a set-up that worked for me.

On the evening of Day 2 (60 hours), use a spray bottle to water the seeds. Drain off excess water. Repeat 1-2 times. I use the spray bottle so the seeds aren’t disturbed.

Leave the jar on the counter away from the window, and use the canning lid to cover the jar, leaving a gap.

Day 3

On the morning of Day 3 (72 hours), water the seeds using the spray bottle and drain. Repeat 1-2 times.

Set the jar before a window so it can get some indirect sunlight and green up. Avoid direct sun rays to prevent excessive drying.

The frog lid is added on this day. It will prevent the grass from being pulled up in clumps by my kitten when the grass is ready to be munched on. If your cat only nibbles on the grass, you can skip the frog lid.

By the morning of Day 3, the grass is probably approaching the top of the jar, so, after watering and draining, screw on the frog lid. If the grass is not close to the top, wait until the evening, rinse and drain, and then screw on the frog lid.

The blades of grass grow up around the wiring of the frog lid. The frog lid is screwed on before the grass reaches the top so grass blades don’t get twisted around. However, it is more difficult to drain off excess water with the frog lid on, so I wait until the blades are close to the top of the jar.

On the evening of Day 3 (84 hours), water (through the frog lid, if the frog lid is already one), using the spray bottle. Drain. Repeat 1-2 times.

Days 4-6

Continue watering twice a day using the spray bottle, making sure to drain off excess water, and continue to sit the jar in front of a window or under a grow light.

If you see mold growth at any time, dump out the seeds and thoroughly clean the jar and lids. You’ll need to start over again.

By Day 5 or 6, the grass is usually tall enough to offer to my kitten. Wait another day or two if you would like the grass to be taller.

I continue to water the grass using the spray bottle twice a day, shaking off excess water, for the duration of the grass’ short and brutish life.

The grass usually gets decimated by my kitten in under a week, at which time its remains go into the compost bin. Otherwise, keep an eye out for mold growth at the roots. Toss the grass right away if you see any.


  • KissyCat – How to Grow Wheatgrass for Your Cat in 10 days (YouTube) – KC’s human uses a jar sprouting method, then spreads the germinating seeds on a plate and waters them using a spray bottle. The best part of the video is the appearance of the cute black and white cat, supervising the process, and eventually enjoying the grass.
  • Korean Gardener – How to Grow Wheatgrass (YouTube) – KG uses a jar sprouting method, then grows the grass (actually barley, not wheat) in a variety of containers, with and without soil. She shows that they are all successful. She waters with a spray bottle as well as under a faucet. The grass is harvested and made into juice for human consumption.
  • Sew Historically – How to Grow Wheatgrass Without Soil – SH soaks and grows small portions of wheatgrass in glass bowls, rinsing the seeds under a faucet. The grass is harvested and used for human consumption.
  • Sproutpeople – Growing Sprouts and Microgreens – this is a storefront selling seeds for sprouts and microgreens. The owners are long-time growers and sellers, with information on the process of sprouting, which I found helpful. They recommend using a grow medium for growing cat grass.

I am not affiliated with any of these brands.

I also viewed a number of other websites and how-to videos. The links I chose have the most relevance to my method.