Cacti are one of the easiest plants to grow in the home. They can withstand drought conditions, where other plants would have turned crunchy and dry. Although cacti are easy to grow when they are big, starting them from seed can be challenging. You will need lots of patience, and the right conditions for the seeds to germinate. Most cacti started from seeds grow under artificial lights for the first few years.
Buying the Seeds
You can buy cactus seeds at most garden centers, gardening catalogs or online. Some packages are one variety, while others are a mixture of different cactus seed. Pick the kind that you want to plant. We often pick the variety packages, because my mother the different kinds of plants.
Choose the Right Container
Find a shallow ceramic container that has drainage holes at the bottom. Or, you can fill several 2-inch containers with cactus soil. Each pot can hold up to 20 to 30 seeds, so fill as many as you need. Some people sow the seeds this way, but when I prefer to plant 6 to 7 seeds in each container, spacing them out equally. By sowing the seeds this way, the cactus can grow in the same container until they are the size of a marble. When they reach this size, it is time to transplant them into separate containers.
Filling the Pots
Fill your chosen containers with cactus soil. You can find this special soil in the same places where you bought your seeds. If cactus soil is not available or you want to mix your own, combine 4 parts top soil with one part perlite and a handful of coco core. Cactus needs a fine soil, so sift or break up any clumps you find with your fingers.
Water the cactus soil thoroughly. Find a container with sides and fill it with water. Place your filled pots in the water to soak. When the top of the soil is visibly wet, remove the pots.
Sowing the Seeds
Scatter the cactus seeds on top of the soil thinly and evenly. Lightly press the seeds against the soil to ensure the seed coat is in contact. Cacti seeds need light to germinate so don’t cover them with soil. Place the cacti container into a sealable plastic bag. Although a baggie can hold several pots at one time, it is a good idea to place each pot in its own bag. If a fungus starts, it will affect only one pot and not all of them.
Find a Bright Location
Place the baggie in a bright window or under grow lights. The proper distance for the grow lights is 12 to 15 inches away from the surface of the soil. Turn the lights on for 12 to 18 hours a day. You’ll want the soil to remain around 75° to 80° Fahrenheit. If you don’t have a warm area to set for the pots, place a heat pad beneath the container to regulate the temperature. If you have an old aquarium with a light, you can use that instead. Line the glass with foil so it will be bright inside.
Check the soil daily for moisture. If the soil starts to dry out, mist the top with water to keep the soil moist so the seeds can germinate.
Depending on the variety sown, some seeds germinate in a less than a week, while others can take two months or longer. If you notice the seeds turning red or shriveling, that means you are keeping the area too bright.
After the seeds have germinated, continue to grow them in the sealed plastic bag for another three months. After that time, slowly open the bag to allow for air circulation. The first day open the bag an inch. The next day open it a little more. Continue to do this over the course of a week until the bag is fully open. For another two days, leave pots in the open bag.
Water the top of the pots with a fine mist sprayer. Water the soil well, but do not make it soggy. Young cacti need moisture. Older cactus can grow with very little moisture and full sun exposure.
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