The Ornithogalum dubium plant is from the lily family and is native to South Africa. The flowers are also known as sun star or orange star. You can grow Ornithogalum outdoors as a perennial in U.S. Department of Agriculture (USDA) Plant Hardiness zones 8 through 11 or in colder zones as an annual. You may also grow the flowers indoors in containers in any zone. The long, leafless stems of the plant make for wonderful cutting flowers and are often used by florists for their beautiful color and long-lasting flowers.
Water thoroughly after planting to soak the soil. Make sure the soil is draining well as the bulbs will rot if left in standing water. Water from beneath if the plant is in a container and take out the tray after a few hours if the plant has not soaked up all the water. Keep the soil moist during the growing season, then cut back to once a week while the foliage is dying off. Withhold water while the plant is dormant, just don't let it totally dry out. Start to water again when you see the plant begin to grow again.
Work compost into the soil if the water is not draining well, or use a top-dressing to enrich the soil. A handful of compost is enough for a container, or two handfuls for outdoor beds.
Use a bulb fertilizer in early spring once a year. Follow the manufacturer's suggestions on the amount to use per how many bulbs you've planted.
Cut flowers anytime for use in vases. Prune off foliage only after it has turned yellow and is dead. Before this it is still gathering sunlight to use for the next year's growth.
Mulch over the soil to protect the bulbs from frost during the winter if planted outdoors. Indoors, keep the container in a cool, dry area for three months after the foliage dies off, as the bulbs need a rest period before they start a new growing season.