Cacti are members of the Cactaceae family. They are distinctively different from other plants, as they are the only ones that can survive in an extremely hot and dry climate. They are succulents, which means their form is such, that they can conserve water. They make for beautiful ornamental plants, and those who have them, can go on and on about the different types, the vivid and vibrant colors of their flowers, set against a dry arid background. So now, you are tempted to grow a cactus, or perhaps are keen on adding more variety to your plant collection. Well, buying one from a nursery could be an easy option, but there are more exciting alternatives. It can be propagated through seeds, cuttings, or divisions.
How to Grow Cactus from Seeds
Although cactus seeds follow the usual steps of germination, propagation from them is a slow process, as, unlike other plants, they don't germinate within a week. Depending upon the variety of the plant, and the quality of the seeds, they generally take anywhere between 2 to 16 weeks to germinate.
Cactus seeds can be bought from nurseries, or collected from the pods of a plant that has flowered. Remove the entire intact mature pod from the plant, then with a sharp pen knife, very gently cut open the pod. Spread a sheet of paper on a flat surface, and shake the seeds off from within, without touching them. Leave them on the paper to dry at room temperature. If you manage to collect a large quantity and do not wish to germinate all of them, then store them in a dry airtight container.
To grow cactus from seeds, complete water drainage of the soil is essential. Of all the different types of soil, the soil mix for cactus should be free draining, and should not act like a sponge by retaining moisture. It should not be rich, and must be devoid of all organic materials, as moist organic matter can promote the growth of fungus and damping of the seeds. The gravel or sand you add to this mix should not be fine. Fine sand tends to bind the soil, whereas gravel that is slightly big in size will allow the water to flow freely. The soil mix should contain one part washed sand, one part free-flowing soil, and one part perlite. The seeds can be grown in large or small containers, or even in Styrofoam cups. At the base, layer some bricks and charcoal pieces, fill the soil up to three quarters of the pot, gently pat it down to eliminate air pockets and flatten the surface.
Sow seeds in early spring, this way, the germinated ones will have enough sun as they establish themselves. Sprinkle them evenly on top of the soil. For very fine types, mix with a little sand for even distribution. Cover them with a sprinkle of very fine sand. There are two ways to water your container. For plastic or earthen pots, spray mist, or place the pot in a shallow tray of water until the top of the growing medium becomes moist. If you are using a Styrofoam cup, spray mist. As cactus is quite susceptible to damping, add a little liquid fungicide to the water, before watering the seeds. The water should drain out completely. Cover the pot with a clean plastic sheet, and leave it undisturbed in a place that receives sunlight, but not direct heat. One can even use fluorescent bulbs for germination, instead of natural light. Turn off the light at night though. The soil should not dry out, at the same time it should not be too damp. Spray mist only when you feel the soil is beginning to dry out.
Depending upon the variety and quality of the seeds, they will germinate within a few weeks. Once the seedlings are one or two inches tall, gradually acclimatize them to warmer, drier, and sunnier conditions. Water as per need, but never over water. As cactus is a slow grower, it may take a couple of years before one can transplant it into individual pots.
Growth of a cacti may be a time-consuming event and painfully slow, as seeds take time to germinate, but in a few years, when they bear bright colored flowers, or take unusual shapes, you will realize that it was all worth the wait!