Growing Agapanthus Indoors
I note that I have no idea why it is called Lily of the Nile when in fact it is native to Cape Province in South Africa and nowhere near the Nile River.
Grow this plant in full sun. If you find the leaves are getting long and strappy looking (falling over) then it is not getting enough sunlight. Supplement the light with grow-lights.
The container soil should be a good potting soil as this plant loves a fertile soil. As with most container plants, do not use garden soil as it compacts too easily.
Feed while it is actively growing and flowering. Feed weekly with a regular strength house-plant food (balanced formula is fine) I note it should be actively growing in the spring and summer.
Water to keep damp (drying out slightly between waterings) and after bloooming during the fall and winter allow the pot to be more dry than wet. This allows the bulb to rest and mimics the drier season in South Africa.
Growing Agapanthus bulbs will become quite large and multiply in the pot. A bulb can withstand extreme crowding with no problem so do not be in a hurry to divide the plant.
If flowering is reduced because of crowding, then dig up the root mass (in the early sprig just before active growth) and divide all the bulbs apart. Replant several bulbs to a pot to start the process again.
You may find slugs and snails like this plant so if you summer it outdoors, do check for hitch-hikers.
And overwatering is the likely cause of any fungal problems or rotting bulbs.
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