Answer: First off, regarding lighting, if you want to grow cactus from seed this is important, they will not germinate without light. With fluorescent lighting you can plant at any time of the year. If you are planning on using natural lighting, you should probably wait until the spring (April and May) when the days start to get a little longer. Seedlings should never be exposed to direct sunlight. It is important that you use a sterile mix for starting seed, you will want to look for one designed for cacti and succulents. Fill your pots with the mix. You may want to use one of the "seed injectors" to assure even distribution. A good rule of thumb is 25 - 50 seeds per 3" pot. They should be planted fairly shallow. Sprinkle a thin (very thin) layer of sterile sand (hardware stores sell "play sand", this is sterile when you buy it) over your seeds, just barely covering them. Place your pots in a pan containing shallow water, around 1-2". When the sand becomes moist, remove the pots. <br><br>If possible, place the pots in one of those gallon sized ziploc bags (zipped shut) under light. The cactus seeds need humidity and light to germinate. When germination occurs, take the pots out of the bag, and set in an area with good air circulation. The soil should be kept consistently moist for a few months (approx. 3) and then you should gradually begin to ease up on the watering, let them dry out every now and again and then lightly water. Burpee doesn't currently offer cactus seed but it can be obtained from SBE Exotic Seed at http://www.seedman.com/cacti1.html.
Q&A Library Searching Tips