Question
Thank you for your response, Greg.
Can you give any advice regarding transplanting? They are now 1/2 inch high. There are at least 20 cacti per container. I don't imagine that they have a great deal of roots at this point. When planting the seeds initially, I was instructed to simply spread them ON TOP of the soil. What do I do with a 1" tall cactus? Lay it ON the soil and let the roots find their way or attempt to plant this tiny plant IN the soil? And once transplanted, should you water right away or wait until the shock subsides? Thanks a lot for any help you can provide.
Brian
Followup To
Question -
Hello Greg:
I recently visited New Mexico and brought home a couple of cactus growing kits for my kids. We started them two weeks ago today. They are a mix of varieties, and have grown to about 1/4 inch high already. The containers are plastic, about 2" across, and have a clear plastic lid, which I removed 3 or 4 days ago. I watered the soil initially from the bottom, and then added about 1/4 inch of water a week ago. There are at least 12 - 15 plants per container. The instructions provided nothing further. Now what? Do we wait until they get a certain size to thin them out by transplanting each plant? What about watering? The directions stated that they should be kept out of direct sunlight, which we've done. It seems like a lot of plants per container. Can you offer any advice? Thank you.
Answer -
Dear Brian,

You can thin them out once they are about an inch tall. Water them only when the soil is dry, but don't let it stay dry for too long. Everything else you've done sounds like you're doing the right things. Just be patient. Depending on the species, cacti grow pretty slow. Extra light and water will only cause damage.

Remember, cacti in the wild live under a "host" plant for years that keeps them from direct sunlight and keeps the soil moist for longer periods. Sounds like your doing great so far! Good luck.

Sincerely,

Greg

Answer
Dear Brian,

You'll need to plant them vertically. You can support them with popcicle sticks if need be. You can water them initially, but wait until the soil is dry before watering again. The best way to water is to sit the pot in a shallow dish of water and allow the water to seep up into the pot, that way the plant is not disturbed. Make sure and watch for fungus and if you see some, remove it ASAP! Hope this helps.

Sincerely,

Greg