Hibiscus syriacus Red Heart, Rose of Sharon, Shrub,Cold Hardy,Perennial
Late summer color can be hard to come by in perennial gardens. Rose of Sharon (Hibiscus syriacus) blooms into fall with large funnel-shaped flowers that can be white, pink, red, lavender or bi-color, with single or double layers of petals. The shrub grows 8 to 12 feet tall and is hardy in U.S. Department of Agriculture plant hardiness zones 4 through 9and areas of higher zones where temperatures are not extreme. As flowers fade, those that were pollinated develop into large seed pods. Harvest those pods, and you can have as many of these easy-to-germinate shrubs as you wish.
Sow rose of Sharon seeds 1/4 inch deep in full sun in the fall; they will come up in the spring. To start seedlings indoors to have ready for spring, start them 12 weeks before the last frost in your area in sterile potting mix.
The seedpods of rose of Sharon are upright and rounded with five lobes that contain three to five seeds each. The seed pods mature from green to woody and brown over six to 14 weeks. The seed type is referred to as dehiscent, meaning that it splits open along a seam to disperse its contents when ripe. In the case of rose of Sharon seeds, each lobe splits open when the pod is dry to release the seeds.
Because the pod naturally opens when it is dry, volunteer rose of Sharon plants pop up wherever the seeds fall. When you want to control propagation of new plants, you have two options. You can pick the seedpods when they turn light brown and store them in a container until they break open or you can tie small paper bags over the pods while they are still on the shrub to catch the seeds when the pods open.
Save rose of Sharon seeds in a cool, dry place. Place the harvested seeds in an envelope labeled with the variety and the date. If you plan on holding the seeds over until spring, the seeds stay fresh for up to one year when you seal them in a jar and keep it in the refrigerator. Pouring a small amount of rice or powdered milk in the bottom of the container prevents any moisture from causing the seeds to mold and spoil.
USDA Zones: 5 - 10
Height: 48 - 60 inches
Bloom Season: Summer through fall
Bloom Color: Mix
Environment: Full sun
Soil Type: Moist, well-drained, pH 5.8 - 6.8
Average Germ Time: 14 - 21 days
Light Required: Yes
Depth: Cover lightly, seed should be visible
Sowing Rate: 2 - 3 seeds per plant
Moisture: Keep seed moist until germination
Plant Spacing: 36 inches
Materials: seeds,summer,bloom,HIBISCUS,Rose of Sharon,Perennial,USDA Zones 5 to10,Cold Hardy