Growing Hibiscus

Growing Hibiscus is an easy way to bring big color to your garden. The enormous (up to 8-inch) blooms of the Hibiscus appear in mid to late summer and are available in a host of colors from yellow through red to blue. Although hibiscus plants thrive in rich soil, they do surprisingly well in average soil that is kept moist.

Growing Hibiscus Successfully

Variety: Hardy Hibiscus Hibiscus moscheutos
Zones: 5 to 10
Soil Type: Moist, organically rich soil
Soil pH: 6.1 to 6.5
Sunlight: Full sun to partial shade
Availability: Sold as seeds or nursery grown container plants. Hibiscus don't mind crowded roots, so don't be put off by an otherwise healthy plant that seems root bound.
When to plant: Hibiscus seeds can be planted six weeks before the last expected frost. Young plants can be put in the ground after the threat of frost has passed.
Planting Method
Seeds: Hibiscus seeds should be planted in small pots of potting soil. Seed should be nicked on the flat bottom part with a utility knife before planting. Keep soil moist.
Live plants: Hibiscus plants should be placed in a sunny location that is protected from winter winds. Hole should be as deep as existing container and three times as wide. Amend the backfill soil with organic material for best results.
Watering: Hibiscus plants should be well watered so as not to allow the soil to become dry.
Fertilizing: Feed Hibiscus plants throughout the growing season with a balanced 10-10-10 fertilizer mix.
Diseases
Sooty Mold: appears as a black powdery substance on the leaves of the plant. Sooty mold usually forms in the presence of aphids or mealy bugs. Mold should be wash from leaves with warm, soapy water. Addressing the insect infestation will limit the appearance of sooty mold.
Pests
Aphids: Small, soft-bodied insects that suck moisture from plants. Ladybugs are a great way to control aphids. Consider insecticidal soaps as an alternative to pesticides.
Thrips: These tiny, yellow or tan insects eat the pollen from plant blossoms. An infestation of thrips can lead to undersized or malformed fruit. Remove infected blossoms and treat plant with insecticidal soap.
Japanese Beetles: These ½" long metallic green beetles have no natural enemies in the US. Japanese beetles are voracious leaf eaters. The best way to remove Japanese beetles is to kill their larva. The larvae are usually found under turf grass and can be eliminated using grub-specific pesticides or organic treatments like milky spore. Adults may be captured in traps, but don't place traps near the plants you want to protect.
Mealybugs: Tiny beetle-like insects with a white furry coat, mealybugs suck sap from a plant. Mealybugs secrete a sticky substance that promotes the growth of sooty mold. Treat the infected plant with insecticidal soap. Make sure to apply soap to the joints where leaves meet the branch-a favorite mealybug hideout.
Saving Seeds: As Hibiscus flowers fade, the seedpod will appear as a brown swollen area behind the bloom. Remove the seedpods and split them open when they've turned dark brown. Remove the seeds and allow them to dry in a cool, dry place. Store the seeds in a paper bag until the spring.