Germinating the seeds
Seeds germinate well if they are fresh. Use any small containers or cups that have drainage holes.
I recommend using well-draining soil, such as cactus mix, or a mix of 1 part potting soil to 1 part perlite or coarse sand. Fill each container almost to the top with soil. After filling the containers, water the soil so that it is uniformly moist, but not soggy. Place 1 or 2 seeds on top, and drip some water on the seeds to settle them in the cracks in the soil. Don't bury them completely, because the seeds need light to germinate.
Until the seeds sprout, ensure that the surface soil never dries out. The best way to do this is usually to place the pots in a plastic dome or bag. Leave it open a crack for fresh air to enter. Every day or 2, drip a few drops of water on the surface to keep it moist.
Keep the pots at about 60-74 degrees F (16-23°C), in bright light out of direct sun. Avoid letting them get above 77°F (25°C) . I recommend keeping a minimum/maximum thermometer near the pots. A fluorescent bulb placed 4 inches (10 cm) away provides the right amount of light.
The seeds should start sprouting within 4 weeks, but allow up to 8 weeks for any slow ones. Increase the air ventilation slightly after they sprout, but continue keeping the soil surface moist until the seedlings are 4 weeks old. After 4 weeks old, you may remove them from their plastic container, and allow the soil surface to dry out between waterings.
Lighting -- Give your seedlings bright light, but avoid strong sun for the first few months. Then gradually give them more sun, until eventually they are in a half day of sun, with some protection from hot afternoon sun. After about 8 months they should be ready for full sun, except in hot climates, where they should have a little afternoon shade.
Watering: Aim to keep the soil lightly moist most of the time. Avoid letting the soil completely dry out, but avoid keeping it constantly soggy. And of course don't let the pots sit in a tray of water.
Fertilizing -- For the first 2 months, feed weekly with a dilute (1/8 strength) liquid fertilizer. Hydroponic fertilizer is ideal for this. After 2 months, feed about every 2-3 months with a general-purpose granular fertilizer.
Transplanting -- Repot your plants to a larger container once they are 3-4 months old. Water the soil well before repotting to keep the soil ball from breaking apart, which can damage the roots. For the first 2 weeks repotting, protect from strong sun and give no liquid fertilizer.
After a few years, they should be ready for a 5 gallon (20 liter) pot. A mature colony of plants will need a larger container eventually. Use cactus soil when you repot.
Climate -- Protect your plants from frost for at least the first winter or two. Also keep the soil fairly dry during the winter, unless temperatures are above freezing. They will bloom the soonest if protected from frost. During the summer, it's best to give them some afternoon shade if temperatures get above 90 degrees F (32°C).
By the way, the leaves will develop a white powder on them. This is normal!
Have fun growing them!
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