When to plant -- Plant your seeds when you receive them for best germination.
Getting started -- You may plant each seed in individual, small containers. Or you plant them all in a single
container, but it may be more difficult to transplant them later. Either way, use pots with drainage holes
For soil, use a well draining mix high in organic matter. A typical mix is 2 parts potting soil to 1 part perlite or
coarse sand. An alternate mix is 1 part perlite to 1 part coir fiber, with some slow-release fertilizer
Fill the pots with soil, and water it until uniformly moist (but not soggy).
Place a seed on the surface and drip some water over it to settle it in the
cracks in the soil. Light helps the seeds germinate, so they should not be
buried completely, but if the seed is not settled into the cracks, sprinkle a
thin layer of soil around it, to help keep it moist.
Until the seeds sprout, ensure that the surface soil always stays moist. A plastic dome or bag
is good for maintaining moisture, but leave it open a crack to allow some fresh air in. You may need to drip a few drops of water over the seeds every day to keep the seeds
The ideal temperature for germination is between 65 to 74 degrees F (18-23°C). A little cooler at night is ok.
Avoid letting them get above 77° F (25°C). I recommend placing a minimum/maximum thermometer near the pots.
A fluorescent bulb kept 4 inches (10 cm) away provides the right amount of
light. Protect from direct sun.
They should start germinating in 3 to 5 weeks, but allow up to 8 weeks for any slow ones to sprout.
Increase air ventilation slightly after sprouting to prevent rot, but continue keeping the
soil surface moist for 3 weeks after sprouting.
Lighting -- This Impatiens prefers bright shade, or filtered sunlight. Avoid
strong afternoon sun.
Fertilizing -- For the first month, it's best to give a very dilute (1/8
strength) liquid fertilizer. Hydroponic fertilizer works well for this.
After the first month, feed about every 2 months with a slow-release (pelleted or organic) fertilizer,
or feed monthly with a liquid fertilizer at half strength.
Transplanting -- When your plants are 2-3 months old, you may gently
transfer them to a larger pot. Water the soil first, and avoid letting the
soil ball break apart, which can damage the roots. After transplanting,
give no sun or liquid fertilizer the first week.
Watering -- Aim to keep the soil moist, but not soggy. Never let it dry
out completely. You may use a moisture meter probe to monitor the moisture levels down in the root zone.
Impatiens, it is happiest in moderate daytime temperatures and cooler
nights. It might not thrive if temperatures consistently get over about 85
degrees F (29 C) and nights are warm. I don't think it can survive below 30
degrees F (-1 C).
You may save the seeds each year
and grow the plant as an annual.
40-50% humidity is best. If your indoor humidity drops too low, consider using an ultrasonic room humidifier, which you can buy at
home improvement stores and thrift shops.
It's normal for a leaf to occasionally turn yellow and drop, but if it seems excessive, the plant may need more fertilizer,
or the soil may be too dry down in the root zone.
Pests to watch for -- aphids, scale (dark disks on the stems), mealy bugs.
Start with insecticidal soap before using stronger remedies.