Question: How do I go about starting cactus seeds indoors?
– Tampa, FL
Answer: The best times for sowing cactus seeds are late winter and early summer. Use a commercially prepared seed-starting mix or create your own soilless mix composed of equal parts peat moss, perlite, and vermiculite. To reduce the chances of damping-off, pour boiling water over the medium three times, allowing it to drain each time.
Next, fill a shallow container with the moist medium and sprinkle the seeds (which should be fresh and from a reputable source) onto the surface. Large seeds should be pressed lightly into the surface with
a flat object. Enclose the container in a plastic bag to maintain high humidity and place it where it receives indirect light and a temperature between 70 and 90 degrees Fahrenheit.
Providing bottom heat will improve germination. In general, expect most cactus seed to germinate within two weeks to a month. When the seedlings emerge, remove the plastic bag and gradually acclimate the seedlings to full sunlight.
Do not allow the medium to dry out, and water the seedlings with a dilute liquid fertilizer at least once a month. Don’t rush to transplant the seedlings. Keeping them in the flat for six months to a year encourages the development of strong roots.