Getting started -- Use well-draining soil. A good mix is 2 parts potting soil to 1 part perlite or coarse sand.
Use small containers or cups that have drainage holes at the bottom. Fill them to within 1/2 inch (15 mm) of the top with soil. Water it so it is uniformly
moist, but not soggy. Place 1-2 seeds on top of each pot, and drip a few drops of water on them so they settle in to the cracks in the soil. The seeds need some light to
germinate, so don't bury them completely.
Until the seeds sprout, ensure that the surface soil never dries out. If you place a plastic dome or bag over the
pots to maintain moisture, leave it open a crack to allow some fresh air in. You may need to drip a few drops of water on the seeds each day to keep them moist
For lighting, a fluorescent bulb kept 5 inches (12 cm) away provides the right amount of light. The ideal temperature
for germination is between 65 and 75 degrees F (18-23°C). I recommend placing a thermometer near the pots to ensure they stay at the right temperature.
The seeds should start germinating in 3-5 weeks, but allow up to 8 weeks for any slow ones to sprout, especially at cooler temperatures.
Lighting -- This Impatiens prefers bright shade or filtered sunlight. Avoid prolonged direct sun, unless it's early-morning sun. Once the plants are a few months
old, you may experiment with giving them more sun.
Transplanting -- When your plants are a little taller than their pot, gently transfer them to a larger pot, about 1 gallon (4 liters) in size. Once they reach
about 2 feet tall (60 cm), transplant again to their final container, which should be about 2-5 gallons (7-20 liters) in size, depending on how large you choose to let your
Transplant carefully to prevent the soil ball from breaking apart. Watering before you repot will help prevent this. After
repotting, avoid packing the soil down, and give no fertilizer or direct sun the first week. Double this time if the soil ball breaks apart.
Watering -- Aim to keep the soil evenly moist, but not soggy, most of the time. You may use a
meter to monitor the moisture down in the root zone.
Climate -- Impatiens usambarensis comes from a climate that is mild all year. I know it can handle temperatures in the 80s (30°C), however
it is untested in warmer areas like Florida. It should do fine wherever the common Impatiens walleriana is grown, since they come from similar areas in Africa.
The plant probably has a few degrees of frost tolerance since it can grow back from the base, but i recommend protecting it from temperatures below 35° F (1°C).
The humidity should be above about 40%. If your room humidity is too low, consider using an ultrasonic room humidifier,
which you can buy at home improvement stores and thrift shops.
Fertilizing -- Your Impatiens has average fertilizer needs. About every 2 months, give a slow-release (pelleted) fertilizer.
It's normal for an older
leaf to occasionally turn yellow and drop, but if it seems excessive, the plant may need more
fertilizer, particularly nitrogen. Also check that the soil is moist enough down in the root zone.
Pests to watch for -- aphids, spider mites (tiny "dots" and webbing under the leaves), whitefly, mealy bugs.
Certain spider mites can't be seen but may deformities of the new leaves. Be careful when choosing chemical remedies, because some may harm the plant. Email me if you