Germinating the seeds
Your seeds should be planted immediately for best germination. Stored seeds don't germinate well.
Getting started - Soak the seeds overnight in a cup of water. If your seeds arrived wet, rub off any gelatinous coating on a towel before soaking them.
Cold treatment. Your seeds should be given a 6 week cold treatment in the refrigerator for best germination. This tricks them into thinking winter has passed, so they germinate better. The instructions below explain the process.
Prepare a soil mix of about 2 parts potting soil and 1 part perlite or coarse horticultural sand. An alternate mix is equal parts of coir fiber and perlite (use small- or medium-grade perlite, not big chunks). Fill a small, plastic ziplock baggie a small amount of the soil mix, place the seeds on top, and cover them with some soil. Add just enough water until the soil is evenly moist (there should be no water on the bottom) and zip up the baggie.
Instead of a baggie, you may use a small plastic Tupperware-type container. You will be digging the seeds out later, so don't use a big container and lots of soil, or the seeds will be difficult to find.
Place them into a refrigerator that stays above 37º F (2ºC). Inside the door is usually the warmest part of a refrigerator. Mark your calendar to remove them after 6 weeks.
After cold-treatment -- Use pots about 3-4 inches tall (8-10 cm) and 3 inches wide, with drainage holes. Use the soil mix mentioned above. You may add some granular fertilizer, but don't add lime to the mix, because they prefer slightly acid soil. Place a seed in each pot, cover with 1/4 inch (6 mm) of the mix, and water the soil until evenly moist, but not soggy. If your tap water is very high in minerals ("hard water") it's best to use bottled water or rain water.
Until the seeds sprout, keep the pots between 60-78 degrees F (15-25°C) during the day, and a bit cooler at night (50 to 70°F / 10-21°C). Avoid letting them get above 80 degrees F (27°C). I recommend placing a minimum/maximum thermometer near the pots. Give them some air circulation to prevent stem rot later. The seeds sprout at different times, usually beginning between 6 and 12 weeks, and continuing for another 2-4 months.
Once they sprout, give them bright light, but shade them from strong sun exposure. Water them enough to keep the soil surface from drying out (but again, avoid keeping them soggy). Avoid transplanting them the first year.
Lighting -- Lapageria prefers part sun, with protection from hot afternoon sun. Lapageria likes its roots cool, so try to keep the pot shaded in warmer conditions.
Climate -- Lapageria prefers mild daytime temperatures and cooler nights. It's happiest between about 40 and 85 degrees (5-29°C) with cooler nights (below 65°F / 18°C). Adult plants are said to tolerate down to the low 20s (-5°C) if given overhead protection. But protect your seedlings from frost the first 3-4 years. You may grow them indoors or in a greenhouse provided that the air is cool and over about 40-45% humidity with good air circulation.
Support -- Adult plants prefer to twist around a trellis, fence, wires, etc. Your seedlings will not need a trellis for at least 2 years, since they are slow growing when young.
Fertilizing -- Seedlings grow slowly the first 2 years and don't need much fertilizer during this time. The first 6 months, feed every 2 weeks with a small amount of dilute (1/8 strength) liquid fertilizer. Hydroponic fertilizer is ideal for seedlings, because it is easily absorbed and contains all essential nutrients. After 6 months, you may switch to a granular fertilizer that contains micronutrients, feeding every 4 months. When growth speeds up after about 2 years, increase the feeding to every 2-3 months, except when temperatures are cold.
Potting up - When your seedlings are 12-18 months old, they may be gently transplanted to 2-quart (2 liter) pots, which can hold them for another 1-2 years. They may then be transferred to 5 gallon (19 liter) containers, which can be their permanent home.
Pests to watch for -- Protect from snails and slugs, which love Lapageria. Watch for aphids on the new growth, and spider mites under the older leaves (tiny "dots" on the leaves). Scale (small discs) and mealy bugs may appear on the stems or leaves. Try using insecticidal soap before using stronger remedies, since some may harm the plant.
If you have any questions, please email me.
Have fun growing them!
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