Beginner Gardening: Gloriosa supurba (Fire Lily) bloom issue., 1 by Len_G

Len_G wrote:
This is my first successful year at growing Fire Lilies. I have two growing now and I am generally pleased with the outcome.

Since it was such a cold spring this year, I chose to start them indoors. Once they started growing, they really took off, one in particular...it is just over 5' high. The other, is a mere 3'. Both have branched and are starting to get flower buds on them. The 3' plant has one very healthy flower growing so far, the rest that are coming up darken and stop growing.

With the 5' plant, however, all the flower buds that have begun to grow, have, so far, turned dark and stopped growing for some reason. I water regularly, checking the soil first to see if they do need watering. I feed them a 24-8-16 all purpose plant food when I do water them. The rest of the plant is very healthy, I check it daily for any pests that may have made a home in them and I have found nothing.

(They are in direct sunlight from early morning until about midday then are in partial to full shade during the hottest period of the day. Since I live in a high rise, there is usually a breeze.)

Am I doing something wrong?