Ornithogalum caudatum. commonly called the pregnant onion plant, has a bulb that resembles an exceptionally large onion. Smaller bulbs grow in under the skin of the main bulb, making it appear pregnant. The bulb protrudes above the soil level and has a cascade of drooping, spear-shaped leaves emerging from it. Ornithogalums are usually grown as houseplants or as potted summer plants. They cannot tolerate freezing weather and must be brought inside for winter.
Place the plant in an area that receives bright, indirect sunlight, such as a south-facing window. Areas with morning sun and afternoon shade also will work. Direct afternoon sun will burn your ornithogalum.
Water the plant when the top 2.5 cm (1 inch) of soil begins to feel dry to the touch. Pour water into the drainage tray under the pot and allow the soil to soak up the water for two or three hours, then drain the excess moisture from the tray. Plants do not require watering more than once a week, as ornithogalum is extremely drought tolerant.
Prune the leaves off the plant once they yellow and die back naturally. Ornithogalum constantly produces new foliage as the old foliage dies. Cut the leaves off cleanly at the base with a pair of shears. Cut back foliage to the green portion if the leaf tips begin to brown.
Remove the small bulbs produced by the ornithogalum once they fully emerge and separate themselves from the main bulb. Set these small bulbs on top of the soil in a new pot, where they will quickly root. Place new bulbs with the pointed ends facing upward, as roots are produced on the rounded ends.
Ornithogalums do not require fertilisation. The main stalk of the plant may begin to peel as old foliage dies off. There is no need to remove the peels.