Hibiscus, swamp mallow – whatever…by Tina Clinefelter

The plant name ‘Hibiscus’ can cover a whole swoop of different species including the rose-of-Sharon I mentioned a few weeks ago. This is the small shrub Hibiscus syriacus and I was researching a variety that would not self-sow with the enthusiasm of some of the older types. Rose-of-China is a tropical hibiscus houseplant; by all means let it enjoy a summer vacation outside, but bring it into the house in the fall. The hardy, perennial hibiscus that I researched for a neighbor recently also goes by the name of ‘swamp mallow’ or ‘rose mallow’, so, you see, it is very important to know the plant’s proper name so you get the proper information on care and cultivation.
My friend’s question concerned pruning – how much and when, and as I hate to waste good research I’ll share it with you all. As I now have hibiscus seeds, I may also be able to share plants with you next spring – I’ll keep you posted!
There’s an ad running on TV at present – Big! Big!! BIG! Just keep in mind that hibiscus needs space. There’s nothing shy about this plant with its large leaves and ‘in-your-face’ blossoms so it performs well as a specimen plant, but it also can become a stunning hedge. In a garden bed it definitely is a ‘back-of-the-border’ flower, and it will also do splendidly in a boggy area. Full sun is a must for a shady area will cut back on flower production and promote spindly stems that will need to be staked. It prefers rich soil, but will be happy in most ordinary garden soil as long as water is provided during drought conditions – wilting is a sign of thirstiness!
Now for the pruning requirements: cut the stems back to about 8 inches in fall and mulch with fallen leaves (chopped); when growth begins in late spring cut off all the dead stems entirely. Pinch the new stems back when 1-2 feet tall to promote bushier growth.
There are some insect pests that attack hibiscus but Japanese beetles are likely to do the most damage – get out there in the early morning mists with a container of soapy water and flick the sleepy bugs to their doom! Other pests include aphids, whiteflies and scale, and rust and leaf spots can occur; overall a vigorous and problem-free plant!
So, let’s move on to my new garden progress: I have installed a Viburnum dentatum 'Christom' variety 'Blue Muffin' and in order to do this (not knowing where the electrical and utility lines were buried) I called the PA One Call System. I just dialed 811 and chatted with a cheery young lady who took all my details – address, phone, email address, county, township, nearest intersections, area of proposed digging and size of digging area, who would be doing the digging and when said digging would be completed. The very next day, in my absence, the lawn was marked with paint and flags, crossing the macadam road to the pole, and an email arrived confirming the electrical services had been marked and that water/sewer were not in that area! I was impressed!
The viburnum seems to be doing well, but is probably too small to give me much of a show next year, but I look forward to its glossy foliage, white flowers and glorious blue berries in fall in the coming years!
A quick closing note: ticks are terrible this year, and the Extension Office has a great fact sheet with good colored photos from Ohio State University. If interested, call 726-0022, leave your name and mailing address, and I’ll get a copy to you.