|I have several large Hawaiian/Australian tree ferns growing in my greenhouse, and I've had some spores germinate on their own. How can I propagate them in quantity?|
|That's exciting that you've had spores of your tree fern (Dicksonia) germinate in your greenhouse. If they have grown into plants, that's a good sign that you will have success in propagating larger numbers. Use fresh spores if possible, or store them in a cool, dry place until you are ready to sow them.
Sterilize all containers, soil, and pieces of glass to be used for covering the pots by baking or steaming for one hour at 250 degrees F. Use a soil that contains large amounts of leafmold or peat moss and coarse sand or perlite. Level the surface of the growing medium and scatter the spores, without pressing them into the soil. Cover the pots with glass or use another means of keeping the surrounding air moist. Keep the pots in light but not direct sunlight. Keep the pots constantly moist by watering from the bottom.
Once the prothallia emerge, remove the glass and transplant when they become crowded.
Good luck with your project!