Hardy hibiscus are deciduous flowering shrubs that produce some of the most spectacular flowers you can grow. The flowers range in size from 3 to 4 inches wide to as large as 10 to 12 inches wide. They come in a wide variety of colors including various shades of pink, yellow, apricot, red, multicolored and picotee. Growing hardy hibiscus from seed is relatively simple and once established, the showy flowers will attract both hummingbirds and butterflies to your garden.
Fill up 4-inch pots with a good quality seed-starting planting mix until the pots are full to within approximately 1/4 inch from the top.
Set the hardy hibiscus seeds out onto a sheet of white paper. Use a pair of sturdy tweezers or a pair of jeweler's pliers to grasp a seed. Hold the seed firmly with the tweezers or pliers while you nick off a section from the hard seed coat using a utility knife or a hobby knife.
Dust each of the hardy hibiscus seeds with a general-purpose powdered fungicide. The use of a fungicide will help prevent the tender seedlings from dying from a fungal disease.
Poke 1- or 2 1/4-inch-deep holes in the center of each 4-inch pot. You can use the tip of a pen or pencil to create the holes.
Plant one hardy hibiscus seed into each of the holes. Push the seeds gently into the soil to make sure there is good seed-to-soil contact. Sprinkle no more than 1/4 inch of the seed-raising mix over each of the seeds.
Mist the surface of the soil in the 4-inch pots thoroughly with water. The soil should be visibly moist but not so damp it is dripping with water.
Transfer the 4-inch pots into a brightly lit, warm area in your home. The maximum amount of filtered light should be provided daily. For best germination, the temperature should be between 70 and 80 degrees F at all times. If necessary, contact your local plant nursery or garden center and inquire about purchasing a heating mat. A heating mat is used as a source of bottom heat and will help with germination.
Cover the 4-inch pots with a layer of clear plastic wrap. This keeps humidity high, which also aids in the germination of hardy hibiscus seeds. Keep the soil in the pots moist, but do not water so often the soil is sodden wet.
Remove the plastic wrap once the seeds begin to sprout. Germination of hardy hibiscus seeds usually begins in about five days but can require as long as 3 to 4 weeks. Transplant the seedlings once they are large enough, about 3 to 4 inches tall.