Germinating the seeds
Seed pre-treatment -- Scratch each seed a few times over a nail file or sandpaper to make it easier for water to enter. Then drop the seeds into a cup of water and soak them overnight (no more than 24 hours).
Planting -- Start with small pots or cups that are about 3 inches tall (8 cm), with drainage holes. Use a well-draining soil mix, such as 2 parts potting soil to 1 part perlite or coarse horticultural sand.
Fill each pot with soil and water it. Then put 1 seed in each pot, cover with 1/4 inch (6 mm) of soil, and water the top layer lightly. I get good germination at 65-77 degrees F (18-25°C). I've never tried sprouting them outside this temperature range. It's possible that very warm or cold temperatures may inhibit germination, so i recommend placing a minimum/maximum thermometer near the pots.
They should start sprouting within 2 to 4 weeks, but allow up to 8 weeks for any slow ones. Once they sprout, give bright, indirect light. Protect from strong sun exposure.
Watering -- Carmichaelia likes soil that is lightly moist throughout. Avoid letting the soil dry out completely, but also avoid keeping it soggy. You may use a moisture meter probe to monitor the moisture levels deep in the root zone. Don't let the pots sit in a tray of water.
Temperature & humidity -- Carmichaelia grows well between 45 and 80 degrees F (7-27°C), with cool nights. Since the plant is so rare, i have no information on well it will do outside that temperature range. Feel free to experiment with rooted cuttings. Your plants can be grown indoors, provided that the air isn't too dry. Between 40 and 80% humidity works well. If the humidity drops too low in winter, consider using an ultrasonic humidifier, which are sold at home improvement stores and thrift shops.
Lighting -- It prefers mostly sunny conditions. In warmer climates, some protection from strong afternoon sun may be needed. Also keep the pot shaded in warmer climates, to keep the roots from overheating.
Fertilizing -- The first 6-8 weeks, feed every 7 days with a very dilute (1/8 strength) liquid fertilizer. Hydroponic fertilizer is ideal for this, because it is easily absorbed and contains all essential nutrients. I use General Hydroponics Flora fertilizer, using 1 teaspoon/gallon (5 mL per 4 liters). After 6-8 weeks, you may switch to a granular fertilizer that contains micronutrients, following the dosage on the package. Or continue feeding weekly with liquid fertilizer at 1/8 strength.
Transplanting -- When your plants are 4 inches (10 cm) tall, transplant to larger pots. Water the soil first, to keep the soil ball from breaking apart, which can damage the roots.
Once the plants get about 12 inches tall (30 cm), transplant them to a 2-5 gallon pots (8-18 liters). After 2-3 years, they might need 10 gallons (40 liters) or more.. although smaller pots might work if the trees are pruned back regularly. You may prune the plants to any size that is convenient.
Pests to watch for -- mealy bugs, scale (small brown disks - hard to see), spider mites, slugs & snails. Try using insecticidal soap before using stronger remedies, since some may harm the plant.
Enjoy your plants!
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