How to Care for a Sun Star Flower

When the garden cries out for exotic color, the flame-orange sun star plant (​Ornithogalum dubium​, USDA zones 9-11), also called sunshine lily, more than meets the challenge. This South African bulbous plant reaches just 12 to 15 inches high and grows best in climates with dry summers, according to the University of Arkansas Cooperative Extension Service. In late winter or spring, depending on location, clusters of dainty, star-shaped spring blooms nod above its drooping, grassy leaves.

Sun star flower care is a snap. Simply give this easy-care plant a sunny site with well-draining soil where its toxic compounds won't threaten children or pets.

Sun Star Fertilizer Requirements

A sun star's bulb contains enough nutrients for its first growing season. Additional fertilizer isn't necessary, but working 2 tablespoons of 0-46-0 superphosphate fertilizer into the surrounding 10 square feet of soil prior to planting encourages strong root development. Sprinkle the granules evenly over the soil's surface, work them into the top 6 to 8 inches and water thoroughly.

An established sun star benefits from light fertilizing between the time its flowers fade until its new spring growth emerges. Every other month, dose it with a half-strength solution of water-soluble fertilizer. A 15-5-15 formula works well.

One manufacturer recommends mixing 1 teaspoon of its fertilizer granules in 1 gallon of water; so at half-strength, the sun star would get 1/2 teaspoon. Mix the solution in a 1-gallon watering can and pour it evenly around the base of the plant. Regardless of the brand, use only one-half of the recommended amount. Overfertilizing sun star causes brown leaf tips.

Watering Sun Star

Sun star thrives in evenly moist soil but tolerates dry soil much better than wet. One inch of weekly water when it's actively growing is ideal. Give it supplemental water only when rainfall isn't enough.

A rain gauge keeps track of rainfall. Check weekly and water when the gauge's moisture level measures less than 1 inch. One inch of water amounts to about 6 gallons for every 10 square feet of soil. If the gauge reads 1/2 inch, for instance, give the sun star 3 gallons of water for every 10 square feet. Water slowly, pausing if necessary to let the soil absorb the moisture.

Stop watering when the blooms die back in early summer, when rising temperatures trigger the plant's dormancy. Resume when the new leaves emerge in fall or winter.

Sun Star Flower Pruning

As each flower cluster fades, cut it off at the base of the stem. Sun star's leaves continue photosynthesizing food for the bulb to store over the winter. The orange star plant leaves turning yellow begins to happen as summer progresses. Eventually, the yellowing foliage gradually dies back.

When the leaves are dead, cut them back at the base. The University of Illinois Extension notes the importance of leaving the foliage on plants until it naturally dies back; otherwise, plants will be unable to store enough food reserves for healthy growth.

Use clean, sharp stem cutters to remove the stems and leaves. Sanitize the cutters in rubbing alcohol between cuts to avoid spreading disease. Wear waterproof gloves while pruning to protect your skin from sun star's potentially irritating sap.

Potential Problems for Sun Star

Insects rarely trouble sun star. Rust and leaf spot diseases are occasional problems. Prune any leaves with pale or brownish spots and dispose of them in sealed plastic bags. Sanitize pruning tools by wiping or dipping in rubbing alcohol between cuts and after finishing.

Keep the soil around the plant clear of debris; it may harbor the rust or leaf-spot fungal pathogens. Although unsightly, the diseases rarely do enough damage to warrant fungicidal treatment, according to the University of California.