My Calla Lily bulbs are planted in a pot every spring (I bring them into the house in the winter and store them in a cool dark place). During the summer they get many blooms, but only a few of them turn white. Most of them remain green. I occasionally fertilize them and I try to keep them watered sufficiently. The plant itself is lush and looks very healthy in all other respects. Why don't the majority of the blooms turn white?
Calla Lily Blooming Green Only
Certified GKH Gardening Expert
Calla lilies' flowers normally start out green and will gain color as the flower ages. This is normal. If the buds are not opening fully, they likely need more water. They should be watered at least daily and twice a day if the temps are over 80 F, especially if they're in containers. You can also add some phosphorus, such as bone meal, to the soil.