Cat Grass Needs Drainage to Get the Best Results, Here’s How

plant pot holes at bottom

Does cat grass need drainage to grow?

Cat grass needs if its growing in soil, or a soil-free medium like coconut coir.

However, you can also grow cat grass in water. In this case, your container does not need drainage holes, but it does need a hydroponic base of pebbles or clay.

Your feline friend loves eating grass, and you are buying it in a container at the supermarket, purchasing a cat grass kit, or growing your own from scratch to keep him or her happy. But maybe you’re wondering how important it is for the cat grass container to have drainage holes.

Here are the answers.


Cat Grass Containers with Soil Need Drainage Holes

One of the most common ways to grow cat grass is by using a potting soil mix placed in a planting container. Then, the grass seeds are sowed on top of the soil and left to sprout. Of course, you need to water them every day to make them grow.

When you buy containers of cat grass from the supermarket that are already growing, sometimes these containers do not have drainage holes.

The lack of drainage causes the grass to die quickly, sending you back to the store to buy more, and that’s the point for the company making this type of cat grass. They want it to die soon, so you have to buy more. 

To avoid this, many people grow their own cat grass using supplies from a plant nursery store or the grocery store.

If you grow your own cat grass in a container with a potting mix, it is vital that the growing container has drainage holes in the bottom.

The reason the container needs drainage holes is that, without these holes, the roots of the grass become waterlogged in the soil. Then, the microorganisms in the soil cause the roots to rot, leading to the cat grass quickly dying.


Growing Cat Grass in a Container with Drainage Holes

potting soil

You can easily grow cat grass at home by getting some planting containers with pre-made holes in the bottom, a bag of potting mix, and some cat grass seeds.

You can also take a potting container without holes and drill ¼ inch (.6 cm) diameter holes every 2 to 3 inches (5 to 7.5 cm) apart on the bottom to provide drainage.

To grow cat grass this way,

  1. Soak the seeds in a jar of water for 12 hours
  2. Drain off the water and let the seeds sprout in the jar for another 8-12 hours
  3. Spread about 1 1/2 inches (3.8 cm) or more of potting mix in a container with drainage holes. Dampen the soil mix before sowing the seeds.
  4. Spread the seeds in a single layer on the soil.
  5. Cover the tray or pot with another tray for 2-3 days to keep it dark. This helps the seeds sprout faster.
  6. Remove the cover, put the tray where it gets sunlight for at least part of the day.
  7. Water the seeds daily, and watch your cat grass grow.

When sprouting cat grass, some people like to cover the seeds with a small amount of soil. But this is optional if you cover the tray with another tray for a couple of days to create dark conditions.

The reason you need drainage holes when growing cat grass in soil in a container is so the roots can breathe in the soil.

The holes allow excess moisture to run out of the bottom of the tray when you water, which also prevents mold and mildew from forming in the tray.


Preventing Mold and Mildew on Cat Grass

Sometimes, adequate drainage in the cat grass growing tray is not enough to prevent mold and mildew from forming on the soil and lower parts of the grass.

Mold and mildew on the soil of cat grass is most often a problem when humidity levels are high.

If you are having a problem with moldy cat grass, one solution is to use grapefruit seed pulp extract or a small amount of lemon juice in the water when you soak the seeds.

Grapefruit seed extract is often available at outlets that sell wheatgrass growing kits and supplies. If you use lemon juice, add one teaspoon to a gallon of the seed soaking water.

You can also place a fan on a low setting near the cat grass, so it blows air over the surface of the tray. Doing this reduces the chances of mold and mildew growth.  


Cat Grass Grown in a Soil-Free Planting Mix Needs Drainage

Picture of wheatgrass from Wikipedia

Potting mix soil is not the only type of planting material you can use for growing cat grass. You can also grow it in a soil-free mix made with a variety of potting materials, including,

  • Coconut coir
  • Vermiculite
  • Perlite

Many people who grow cat grass in a soil-free potting mix make a blend of these materials. One recipe is to mix:

  • Two parts coconut coir
  • One part perlite or vermiculite
  • One half part worm casting or compost

It’s important to know that soil-less growing mediums like coconut coir, vermiculite, and perlite do not contain any fertilizer. That’s why you need to add some worm castings or compost because they contain nutrients that will feed the grass.

The main advantage of growing in a soil-free potting mix is that it is cleaner than using a potting soil mix. If your kitty pulls out grass from the mix, you won’t have bits of soil making a mess on the floor.

When you grow cat grass in a soil-free potting mix, you still need to soak the seeds before planting them, water the seeds every day, and expose the container to sunlight or a grow lamp. Otherwise, the grass will soon turn yellow and die.

Soil potting mixes and soil-free potting mixes both need to remain moist but not soggy at all times while cat grass is growing.


Keeping Soil Mix from Flowing out of Drainage Holes

deep plant pot

One problem with growing cat grass in a container with drainage holes is that some of the soil can escape through the holes as you water the grass, creating a mess.

An easy way to prevent this is to put a layer of material on the bottom of the tray or pot before adding the soil mix. The barrier must allow water to flow through, and it should not contain any potentially toxic substances which could harm your kitty.

A piece of clean, cotton cloth, a paper towel, or a piece of agricultural fabric all work for keeping the soil mix in the container while still letting water drain through the holes.


Growing Cat Grass in Water without Drainage Holes

Growing plants directly in water is called hydroponic growing. Obviously, if your container is going to hold water, you do not want it to have any drainage holes.

When you grow hydroponically, you first fill the container with a base material. The base can be small rocks or a special type of expandable clay material made for hydroponic growing.

Next, you fill the container with water and a small amount of fertilizer and place a permeable barrier on the top of the water to keep the seeds from sinking.

You can use a coffee filter, a paper towel, a piece of agricultural fabric, or a fine mesh screen for this purpose.

Finally, you sow soaked seeds on top of the barrier and let them grow. The roots will grow through the barrier and down into the water.

You will need to top off the water level in your hydroponic container when it gets low from the plants drink it up and as the water evaporates.

You may be wondering why the roots of cat grass grown in water do not drown. The reason is because the barrier fabric allows the roots to have access to air, and because most microbes and molds do not survive in water as they do in soil.

When you grow cat grass hydroponically, be sure to use a sturdy container that can’t easily get knocked over or tip if your cat stands on it. Also, be sure the container is not too high that your cat cannot reach the grass at the top.

Finally, make sure the grass is well embedded in the base material before you give  the grass to your cat. This is so he or she does not pull the grass out when eating it.


Fertilizing Cat Grass Growing in Water

You must add a fertilizer solution to the water in the correct amount to feed the grass when you grow cat grass hydroponically. Otherwise, it will not get green and tasty for your cat.

The best solution for fertilizing hydroponic water is to go to a plant nursery that sells hydroponic supplies and ask for a fertilizer suitable for growing cat grass.

Read and follow the instructions carefully on the fertilizer bottle or package. Over or under-fertilizing your hydroponically grown cat grass will cause it to die quickly or fail to grow at all. Also, adding too many nutrients might make your kitty sick.

Writer: Mary Innes

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