How to Plant & Take Care of Hibiscus Plants in South-Central Pennsylvania

Locate a place in your landscape that receives full sun and the air circulation is good, but not so strong as to wind-burn the plant. In the spring when all danger of frost has passed, dig a hole as deep as the root ball and two to three times the width of the diameter of the ball. If your soil tends to hold water, mix leaves or compost with the soil you took out of the hole, before using it as back-fill. Add just enough organic matter that the soil becomes loose and will drain well.

Loosen the container from the plant, and gently slide it out. If the roots are circling the root ball, spread them out. Place the plant into the hole with the roots fanned out. Fill the hole half full of the soil you dug out. Water it with enough water to settle the soil. You want the soil to make good contact with the roots and not have any air pockets. Allow the water to absorb into the ground, then add the rest of the soil until it is even with the ground and water thoroughly.

Spread a layer 2 to 3 inches deep of mulch around the base of the shrub. To deter disease do not let the mulch contact the shrub’s stem. Mulching the plant will help retain soil moisture.

Fertilize with an all-purpose fertilizer for flowering plants. Apply the fertilizer after planting and twice per month throughout the growing season. Liquid fertilizer will need to be applied more often than granular or slow-release products.

Continue to water weekly so the plant receives 1 inch of water per week in the absence of rain. Hibiscus likes moist soil, but not so wet that the water pools. Space waterings throughout the week to keep soil moist.

Prune the plant into a hedge or train it into a tree form by pruning away lower branches as they appear. When pruning, sterilize your pruning tool by spraying it with disinfectant before use, when moving to another plant and when you are done. To create a bushier plant, pinch back the growing tips. This should be done when the growing tips are 8 inches long, then let them re-grow and pinch them back again at 12 inches. Deadhead flowers to encourage the growth of new flowers.

Watch for aphids, whiteflies and Japanese beetles throughout the growing season. If you should see them, treat with horticultural oil by mixing 1 ounce (2 tablespoons) of oil in 1 gallon of water in a container. Transfer to a spray bottle and apply to the plant every seven to 14 days. Shake the spray bottle often while treating to keep the liquid thoroughly mixed.

Cut the stems back to 3 to 4 inches long in September when hardy hibiscus ends its flowering season. The plant will re-grow in the spring. It may be slow to emerge, but once it does, it will grow quite quickly and begin blooming in July.