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Perennial hibiscus: A WOW in the late summer garden

Thursday, September 7, 2017

By Marilyn McKinley

OSU Ext. master gardener volunteer

Looking for something that says “wow” in late summer? How about something showy, bright, bold and tropical-looking – which is hardy in zone 5. Look no further than the beautiful and hardy hibiscus. They are easy to grow, even from seed, are fairly care-free, and when nearly everything other perennial has gone to seed your hibiscus will be in its glory.

Here’s a word of caution. Be sure when purchasing, you get the hardy, not the tropical, variety. The tropical are very pretty – with showy colors, but will die with the first frost, never to return. They are nice for a summer patio/deck plant. But why not have the hardy variety? They can be potted too. Hibiscus come in several shades, mostly of the white, pink and deep red family. I have ordered seeds in blue and in yellow. Looking forward to watching them grow, producing big, bright blooms.

They do need sun. Mine are at the south side of the house and do very well there. As I recall, the soil there has not been amended, I simply toss some granular, long-lasting fertilizer when they start to come up in the spring, and wait. Hibiscus are probably the last perennial to come up in the spring. Every year I wonder if they were lost to the winter. But it seems like almost overnight they pop up. Just before they bloom I do lightly restrain them so they stand up straight. Mine are over 5 feet tall now. They will spread by dropping seeds, and little sprouts are easy to transplant. You can also propagate from cuttings. If you choose to start from seeds, soak them overnight in warm water. Plant them twice as deep as they are big, sprinkle with a bit of soil and water. Seeds should germinate in about 3 weeks.

If you would like to take cuttings, take cuttings from new or soft wood. This is best done in the spring or early summer. The cutting should be at least 4 inches, remove all but the top set of leaves. Follow with usual propagation procedures.

I have not had any problems with insects on my hibiscus plants. However, they might be attacked by spider mites, aphids or white flies. A good shot (underside of leaves too) of insecticidal soap should solve the problem.

I have read that occasionally, as in many flowers, there may be a change in the color of the blooms. Rest assured, no matter the color, these beauties will never fail to impress. PLUS – they are not a favorite of deer!

You can purchase these plants locally for a splash of fall color in the landscape that will return each season.

To learn more about perennial hibiscus, go to: http://go.osu.edu/hibiscus.