Materials - play sand, regular soil (not potting soil), pumice, dixie cups, and clear plastic dome.
Punch holes in the bottom of the dixie cups using a big sewing needle. Mix regular soil and pumice. Fill the dixie cup 3/4 full of the mixture (pumice and regular soil). Pour play sand over the mixture, leaving about half inch space from the top. Soak the dixie cups 'pots' halfway or less in lukewarm water until the sand on top is moist. Remove the dixie cups from the soaking tub and allow to drain. Sprinkle the cacti seeds over the sand in the pots and barely cover the seeds with sand (just enough sand layer to almost cover the seeds). Cover the dixie cups with a clear plastic dome. You can get these plastic domes from 7/11 or Circle K convenience stores. I think they're used for shaved ice or yogurt ice cream cups. Place the pots in filtered light and the seeds germinate in 3 to 5 days. Tip the plastic dome when there's too much moisture inside to prevent mold. Remove the dome 3 days after germination. Keep the soil moist but not soggy or bone dry.
The seedlings are ready to transplant into more dixie cups after a year. Transplant 4 or more seedlings in each dixie cup. When the seedlings are pushing against each other, it's time to transplant again.
I've planted rare/expensive cacti this way. I'm also a member of Central Arizona Cactus and Succulent Society -
would this work if one were to replace pumice with hammered lava rock? basically just a larger grain, right? if so, i might be the next one in on this project. i've been sitting on seeds for a bit now. i'll have to check what they are tomorrow.
What kind of substrate you using??? I got some Aloe seeds I got to plant soon. I used jiffy starter soil last time. But its a pain to water cuz that substrate likes to float. Since you got to plant the seeds in a shallow hole it tends to make them float out and all over the dang place
