We just planted three Hardy Hibiscus that we purchaed from Garden Harvest Supply. The plants are thriving! We need a little help to know your recommendation for winterizing. Mulch…Burlap…Fertilizing? Thanks for helping with this. Mark and Jacquie S.
Answer: Thank you for purchasing some of our wonderful Hardy Hibiscus plants. They are such a great way to create that tropical feel in our yards for those of us in the northern areas. Hibiscus need a dormancy period during the winter. As a broad category, these plants are hardy from Zones 4-9, but some varieties have lower tolerance for cold. Check the information for your specific variety and check your Zone.
For winter care, wait until there has been a killing frost, one that turns the leaves brown, and then trim the stems back. Hardy hibiscus are considered a perennial plant, not a shrub, so they will die down to the ground each winter. To help them survive the cold, cover the plants with a thick, 8- to 12-inch layer of mulch, chopped leaves or pine needles. This will help protect the root ball.
Mark the placement of the plants since these are slow starters in the spring. It’s very easy to think you have lost them, so have patience. The soil temperatures need to reach the 70-degree range to bring them out of their winter sleep. Once you see their new sprouts emerge, give them a dose of a slow-release fertilizer, such as Neptune’s Harvest. Also watch, as some varieties like to self-sow, and you may have some new plants to share with your friends.