How to Grow a Cactus From Seeds

Fill a flower planter with cactus soil. You can buy cactus soil, or make your own. If making your own, use the following ratio: 50 percent coarse sand, 30 percent natural sandy loam and 20 percent grit such as pumice or perlite.

Place two or three cactus seeds on top of the soil. Unlike most seeds, you do not need to bury cactus seeds in the soil.

Sprinkle a small amount of charcoal dust over the seeds and soil. This will help keep algae from growing in the moist conditions.

Water the seeds and soil with distilled water. Use a spray bottle to spritz the seeds and soil gently.

Place a piece of plastic wrap over the top of the planter. Use a rubber band to hold the plastic wrap to the planter. Poke two or three small holes in the plastic for ventilation. Another method is to place the entire planter inside a plastic freezer or sandwich bag. Do not completely seal the bag if you use this method, leave about 1 inch unsealed for ventilation. The plastic over the planter will hold in moisture and help create the humid environment the seeds need to germinate.

Place the planter on a window sill, preferably in direct sunlight. Check the soil every day or two to make sure it stays moist. Water as needed.

Peel back the plastic wrap or bag gradually as the seeds begin to germinate. Do not remove the plastic all at once. Open a larger and larger hole every few days to help acclimate the seedlings to the less humid temperature in the house. Depending on the size of your seedlings, you can leave plastic partially covering them between one month and even up to one year. The added humidity will only help the young plants.