The Gloriosa lily (Gloriosa rothschildiana) is also called the glory lily. It is a climbing lily that can grow six feet or so with tuberous roots. The leaves are smooth, green, and have tendrils that anchor the lily when it is climbing. The flowers are red at the upper halves and yellow at the lower halves. The petals spread so you can see the yellow center and long stamens. Gloriosa lilies flower in the summer. They are hardy from zones nine to eleven, but are also frequently grown in the house on trellises or along bookcases or other objects to climb. All parts of the plant are poisonous if ingested and seed pods should only be handled when wearing gloves.
To grow gloriosa lilies outside, first prepare an area for them by mixing in three inches of compost with your soil. Gloriosa lilies like full sun to light shade. Afternoon shade is helpful in areas with a strong sun.
Plant gloriosa lilies after all danger of frost has passed and the soil has warmed up. Dig holes three to four inches deep and six to eight inches apart. Do not touch the tip of the bulb or you will reduce the chance it will grow. Simply lay the bulb on its side and cover it up. Now water it in well so the soil settles around the bulbs. Water once a week with an inch of water. Make sure that the place you plant the bulbs drains well, as they will rot if kept too wet.
While the plant is blooming, water once every two weeks with half strength water soluble fertilizer, such as 10-10-10. Do not fertilize the plant when it is not blooming.
When the blooms are finished, leave the plant to grow for the rest of the season. Do not cut it back until the leaves are yellow or the bulb will not have enough energy to grow next year.
If you live in a zone where it gets colder than zone 9, you will either have to dig the bulbs up and store them in slightly damp peat moss in the house in a cool, dark area for the winter then plant them in the spring, or treat them as an annual and just replace them in the spring with new bulbs.
You can propagate gloriosa lilies in two ways. The easiest way is to divide the tubers when you dig them up for the winter. Be very careful doing so as the tubers are very brittle.
You can also propagate the lilies from seed. When the blossoms have formed seed pods, let them grow and ripen, then dry out. Wear gloves when handling them. Separate the seeds from any pulp and let them dry out somewhere cool and dry for a couple of weeks.
When the danger of frost has passed and the soil has warmed, plant them one inch below the soil and about six to eight inches apart. Water them in well and make sure you water them one inch a week. They will sprout and grow just as they would from their tubers, although it will take a little longer for them to bloom this way.