Every day when I let my five cats go outside for a little recreation while I tend my garden, they stop at the first blades of grass they find and chow down on them. After about 30 seconds of gorging, they go on their way; usually one or two will soon regurgitate the greens they've just eaten.

This daily routine of the last 10 years has proved to me that cats not only crave grass, but they also apparently need it.

My kitty with the biggest appetite for grass is Boots, who seems to suffer the most from huge hair balls that get lodged inside her gut. A few minutes after swallowing several mouthfuls of grass, she begins to make quiet sounds of heaving. For about seven seconds, the sounds become louder, longer and less frequent until she finally brings back up what she just swallowed, and often there's a sizeable clump of fur that accompanies the grass that she's coughed up.

After the session, she seems to feel bright, sassy and ready to tackle the day.

To me, the routine is similar to how we humans grab a bottle of antacids and throw back a few tablets after a heavy meal. My cats are using a natural cure for what ails them. Whether they learned this cure from their mother or somehow found it out on their own, it seems to work for them and every cat who has access to soft, green grass.

Not all my cats regurgitate the grass they eat. The two males seem to keep it down without a problem. For them, it must provide other benefits, as a laxative or perhaps as a trace mineral and folic acid supplement. Whatever the reason for their daily greens obsession, it's clear to me that cats feel their best when they eat vegetable matter and benefit from access to a steady supply.

The simplest way is to buy a pot at the pet store for about $6.50. However, the pots are small and usually last one cat no more than a week. A cheaper alternative is to grow it yourself.

Cat grass seed can be found at small garden stores or at food stores such as Central Market, but the price for such specifically labeled packets is exorbitant — usually $3 for an amount of seed that fits in the palm of your hand.

A cheaper option is to buy seed from a farm supplier. It might not be labeled as cat grass, but cat grass is merely sprouted cereal grains such as oats, barley or rye, the three most commonly sold as cat grass. Sources such as Sustainable Seed Company offer them for about $8 per pound.

For five cats, I need about two pounds for a year's worth of cat grass. The only other items I need are pots and a bag of coconut coir, which most garden suppliers carry. I've read that wheatgrass is good, but I've also read that wheatgrass upsets cats' stomachs because the blades are sharper, so I usually stick with oats.

To plant the grass, I fill a pot three fourths full with coconut coir. Then I sprinkle the seed on the surface of the coir so that it completely covers it. Then, I cover the seed with about a quarter-inch of coir. I add enough water to moisten the coir but not enough to water-log it.

Rye and barley sprout the soonest — in about two days; oats take about four days to sprout. During the summer, with warmth and long hours of sunlight, the sprouts grow to about four inches high in about a week. In the winter, it takes about 10 days for the grains to grow to this height.

Once a pot is ready, I put it down on the floor where my cats can eat at will. Because I know that the cats will likely regurgitate the grass, I know that a clean-up will follow. In their designated area, the flooring is vinyl, so wiping up the aftermath is no more of a hassle than cleaning their litter box.

I plant the second pot of cat grass as soon as the first pot is ready. After the first pot has been consumed in about a week, the second pot provides a fresh supply. This successive planting schedule keeps one pot on the floor for the kitties and one pot growing out of their reach.

To replant a cat grass pot, I pull out the roots of the eaten grass and save as much coir as I can, top it off with fresh coir and replant it with fresh seed. I only water the pots while the grass is growing; I stop once I give it to my cats.

There's no need to fertilize the pots or to use fertile potting soil because all the nutrients the grass needs are supplied by the seed. The grass will not reach maturity, so additional nutrients are unnecessary.

I avoid using potting soil for cat grass. Potting soils can have animal waste or bio-solids (human waste from a waste water treatment plant), which can carry pathogens and heavy metals. But if you use soil instead of coconut coir, the instructions would be the same.

The seed packet from Botanical Interests suggests that some cats might binge on the grass when first introduced to it; my mother's cat has been indoors all her life and gorged herself on her first experience.

Although my cats have access to grass outdoors, they seem to prefer their pots of cat grass. Cereal grains grow broad, flat, soft blades that are crunchy and moist, unlike the tough, sharp blades of native grasses.

When I treat my cats to a fresh pot, they always get excited and begin nibbling on it as soon as I set it down. It's an easy and inexpensive treat that keeps them healthy and happy while they fulfill their work of rodent control and keeping me company.

Barley (left), oats (top) and rye are cereal grains most suited for growing as cat grass.

  

Photo by Marshall Hinsley

Barley (left), oats (top) and rye are cereal grains most suited for growing as cat grass.