Hardy hibiscus are medium-sized perennial plants that produce dozens of large, dinner-plate-sized blossoms in late summer. The plants die down to the roots each winter but quickly grow again the following spring into a dense bush. Planted in a row, hardy hibiscus makes an excellent seasonal privacy screen because of its vigorous growth habit. They are easy to transplant, and survival rates are much higher for hardy hibiscus that are transplanted in very early spring, as soon as the ground can be worked.
Prepare the new planting site. Dig a hole about 18 inches wide and 24 inches deep. Mix the soil you removed with a 5-gallon bucket of peat moss and a 5-gallon bucket of compost.
Drive the garden spade into the ground around the hibiscus. Begin at a point about 12 inches away from the center of the plant and continue in a circle around it. Push the blade of the spade all the way into the ground using your body weight, if necessary. This will cut some of the roots off and make it easier to dig up. Make another round with the spade, driving it even deeper into the ground on the second round.
Insert the spade into the perimeter of the circle made in Step 2 and push the handle down toward the ground. This will loosen the root ball of the hibiscus so you can then remove it from the planting hole with your hands.
Set the hibiscus down next to the new planting hole prepared in Step 1. Add soil to the pre-dug hole so the hibiscus will be growing at the same level it was before transplanting. Enlarge the hole if it is smaller than the root ball. Put the roots of the hibiscus into the planting hole and back fill the hole with the improved soil. Firm the surface of the soil with your foot.
Use your hands to make a ridge of soil around the perimeter of the planting hole. This will catch rainwater and send it down to the roots of the plant.
Place a hose set to a slow trickle near the base of the hardy hibiscus and allow it to slowly water the bush for 60 to 90 minutes.
Put down a 4- to 6-inch layer of organic mulch such as hay, straw or shredded bark around the planting site of the hardy hibiscus.
Provide your hardy hibiscus with the equivalent of an inch of rainfall per week during the growing season.
Fertilize six weeks after transplanting. Pull back mulch. Spread slow-release granulated fertilizer in a circle around the base of the plant, without it touching the plant. Follow the manufacturer’s recommended rate of application. Replace mulch. Fertilize the plant this way every year in early spring.