Amorphophallus (or Devil's Tongue) bulbs are hardy down to -10C, so can be planted direct outside but may require winter protection. For best results in the first year, it is best to start them off under cover in the spring and move them outside once they have started to grow.
— Plant your Amorphophallus bulbs straight outside during spring between April and May, in a rich but loose and free-draining growing medium. Alternatively, you can start them off indoors between March and May to give them a head start. If planting in containers, you can use multipurporse compost. Add plenty of bark or leaf mulch to the compost for best results.
— Grow in borders or containers in a warm and sheltered but shaded position – under the canopy of a tree is ideal.
— Plant the bulbs 5-10cm deep, with the emerging shoot or the slightly concave side facing upwards. If it is difficult to see which side is which, plant the bulb on its side and shoots will make their way upwards. Space the bulbs at least 15-20cm apart.
— Water-in after planting and keep well hydrated throughout the growing season, not allowing the soil to dry out or become waterlogged. While the bulbs are still dormant in spring, only water when the soil appears to be drying out.
— Amorphophallus may not flower every year. After flowering, spent flower stems can be cut back to ground level.
— In mild areas, or if grown under the cover of trees, bulbs can be left in the ground with a thick mulch to protect them from frosts. In cooler or exposed areas, grow in containers and bring them inside to a frost-free place over winter.