How to Grow Barrel Cactus From Seeds

Fill a 6-inch ceramic pot with a commercial potting soil for cactus and succulents. Use a container with a drainage hole in the bottom. Moisten the potting soil slightly, using a spray bottle. The potting soil should be barely damp.

Scatter the barrel cactus seeds on top of the potting soil. Sprinkle a scant layer of sand over the seeds, using just enough sand to barely cover the seeds.

Place the container in a clear plastic bowl with a snap-on lid. Place the pot in moderate sunlight in a warm room where the temperature will be between 70 and 80 degrees Fahrenheit.

Check the pot every two to three days. If the potting soil is dry, pour a small amount of lukewarm water into the bottom of the plastic bowl. Allow the potting soil to absorb water through the drainage hole until the soil is barely damp, then discard the excess water. Never allow the potting soil to become too wet, as the cactus seeds will rot. Remove the plastic lid and wipe the inside of the bowl with a paper towel if droplets form inside.

Remove the pot from the plastic bowl when the cactus seeds germinate, which may take a few weeks or several months. Place a thin layer of fine, clean aquarium gravel on top of the soil around the seedlings. Move the pot into direct sun and water only when the soil feels nearly dry. Place the pot where the seedlings will have good air circulation.

Transplant each seeding into a 2- to 3-inch ceramic pot when the cactus seedlings have roots that are at least an inch long. Wait several months and don't be in a hurry to transplant the seedlings, as the cactus will tolerate the move better if the roots are well developed.