You see them in your office or local hardware store, maybe even your local Mexican restaurant. But many people never stop to think that cacti actually start out as seeds. I mean it makes sense being a plant and all. But I get the same reaction all the time when I tell people I sell cacti seeds. “Cacti grow from seeds?!?”
The reality is that cacti do grow from seeds, and anyone can grow them. It’s not that difficult and is more than rewarding in the end. I warn you though, the hobby of cacti growing and collecting can be nothing short of addicting, and there is a growing community of cacti growers, particularly the Sacred species, which includes San Pedro Cactus, Peruvian Torch, Dona Ana, certain Ariocarpus species and even Peyote, which is illegal in the United States but it extremely coveted and legal to grow elsewhere around the world.
With a growing interest in starting cacti from seed, I see many people asking about how to begin. This method will not work for every species of cactus, but is ideal for those of the trichocereus, carnegiea, astrophytum, obregonia, lophophora and ariocarpus genus. It will work for other cacti seeds as well. The first consideration to make is soil mix. While you can make your own cactus soil mixtures, this is not really worth it for the new grower. Unless your making a large volume of soil mix, it will be more expensive to buy the multiple materials needed when you could easily buy a commercial cactus potting mix. When it comes to commercial cactus soil, I prefer Shultz’s and am not a fan of Miracle Grow. If it is the only option, it will serve the purpose. Some growers will add perlite (up to 50%), which is a white, porous volcanic glass that is used for drainage. Its nooks and crannies provide an enormous amount of surface area to hold water without letting the soil get soggy. If I am going to add perlite, I find that it is beneficial to use a mixture such as this for the bottom layer. For the top layer, strain out the larger debris so you end up with only the finer particles.
Your next consideration is the pot. This is not a hard choice. I prefer small Chinese soup containers and other take-out containers. Fill your pot with either cactus soil or the soil/perlite mix so that you leave at least an inch of room left. Use a mister to moisten your soil without it getting soggy. Put about half an inch of the finer (strained) soil above that. The finer layer serves to keep the seeds from landing on any debris that they will have a hard time anchoring their root into. Then mist the top layer before you add your cacti seeds. While the seeds of astrophytum are a little larger, those of trichocereus, ariocarpus and especially obregonia are particularly small. When you look at a san pedro cactus or a peruvian torch, you wouldn’t expect that they come from such small seeds. Misting before applying the seeds keeps them from being sprayed away so that they become unevenly distributed. After misting, take your seeds and press them into the surface of the soil. You can crowd them because you will be able to separate them later. Do not cover them at all with soil because cactus seeds need light to germinate.
Cover the whole container with clear plastic wrap. If using a take-out container, you can simply keep the lid on loosely so that air will still get in. Keep your soil temperature at about 70-75 degrees F and provide window light until the seeds sprout. Eventually you can put them under fluorescent lights. The seedlings will not have to be transplanted for at least six months. For continued growing support, please check out World Seed Supply’s venting technique.
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