Hardy hibiscus is a flowering perennial shrub that reaches heights of up to 15 feet. The large tropical-looking flowers come in a variety of bright colors. The hardy hibiscus is related to the tropical hibiscus, but is able to withstand colder weather than its tropical relative. According to Jennifer Schultz Nelson in the July 12, 2009 article "Hardy Hibiscus," this hardy perennial will thrive to U.S. Department of Agriculture plant hardiness zone 4. The colorful flowers of this cold-hardy perennial make a bold statement in the garden.
Fill a bowl with warm water. Place the seed into the water and leave it to soak for one hour before planting, according to the Clemson University Extension.
Fill a 2- to 4-inch planting pot with a mix of equal parts top soil, coarse sand and vermiculite. As an alternative, pick up a seed-starting soil mix from your local nursery.
Wet the soil in the planting pot until it is damp all the way through. Press one seed into the pot and cover it with 1/4 inch of soil.
Put a clear plastic bag upside down over the pot and faster it with a rubber band or twist tie.
Place the pot in a sunny windowsill. Water every few days to keep the soil damp but not saturated. There should be visible moisture droplets on the inside of the bag. If the plastic bag appears dry on the inside, remove it, water the soil until it is damp, and replace the plastic bag. Keep the pot in a place where the temperatures remain above 65 degrees F at night. The seedling will germinate in 2 weeks to 2 months.
Remove the plastic bag as soon as the seedling begins to sprout. Move the pot to an area that gets indirect or dappled sunlight.
Plant seedlings outside or into a more permanent pot when they have four true leaves on them. Wait until all frost has passed before planting seedlings outside.