Use a fibre based house plant compost and water moderately allowing the surface of the compost to become slightly dry between watering. Plants require a bright position and a temperature of at least 15°C (60°F) to promote compact growth and flowering. This minimum temperature is especially important when planting rhizomes. Plant rhizomes about 2cm below the surface of the compost and water lightly. Place the potted rhizomes in a light position out of the midday sunlight.
To help produce an upright plant, use plant supports which clip onto the 12cm pots. Most varieties will start flowering after about 3 months of good growth and continue blooming for the rest of the summer. When in full growth, never allow the pots to dry out completely; as roots appear through the pots drainage holes, start feeding regularly with a high potash slow release Dibleys fertiliser tablet once a month.
In the autumn the plants will stop flowering. Stop feeding and reduce watering; allowing the soil to dry completely as the leaves start to die back. Store the pots in a dry place at about 10°C (50°F). You can harvest the rhizomes from the pots and store them for the winter in a dry dark place at about 10°C (50°F).