Hardy hibiscus, also called perennial hibiscus, produces large, bell-shaped flowers on tall stalks. Standard varieties may reach heights up to 8 feet, while dwarf varieties reach 3 feet tall. While the dinner-plate sized hibiscus flower only survives for a single day, each plant produces so many blossoms that the hibiscus remains in bloom for much of the summer season. Hardy hibiscus is a low-maintenance plant that packs quite the visual punch in the garden.
Work 2 to 4 inches of compost into the top 8 inches of soil in a well-drained garden bed before planting the hibiscus. Compost adds organic matter and nutrients, while also providing further drainage in clay soil and more moisture to sandy soils.
Pinch off the growing tip of each hibiscus plant after transplanting or once the plant has reached 8 inches high if it is an existing plant. Break off the top 1/2 inch of the stem when pinching, as this encourages fuller, bushier growth. Repeat the process a second time when the hibiscus reaches 12 inches tall.
Water the hibiscus thoroughly once a week when it is actively growing, moistening the top 8 inches of soil at each irrigation. Water the plant twice weekly during hot, dry weather or if the soil is drying out quickly.
Spread a 2-inch layer of organic mulch, such as wood or bark chips, over the hibiscus bed. Mulch helps retain moisture in the soil and also keeps down many weeds.
Deadhead hibiscuses one to two times weekly during the blooming period. Break off old, wilted flowers and dispose of them. Deadheading prevents seed production and encourages further flowering.
Fertilize hibiscus plants in spring when they begin actively growing again. Apply a 10-10-10 time-release fertilizer to the bed at the rate recommended on the label.
Cut the hibiscus to the ground with shears after it has died back. Hibiscuses turn brown and die back after the first frost.