How to Grow Tropical Hibiscus
Sunday, June 21, 2015 at 4:00PM The temperature is approaching triple digits outside, and the humidity is climbing. It feels like the tropics. Many perennials and flowering shrubs have retreated from the heat, but there are some tropical plants that revel in the steaminess. Our climate in Alabama is semi-tropical, which means we can enjoy tropical plants outside in the summer, but when frost arrives, these plants will perish unless brought inside. I once rejected tropical plants, because without a greenhouse I don't have a lot of indoor space to over-winter them. However, I have learned to embrace my tropical side, and now I enjoy the bright colors typical of places like South Florida and Hawaii.
Tropical hibiscus (Hibiscus rosa-sinensis) is an evergreen shrub that grows up to fifteen feet tall in frost-free climates, though it can be pruned to control size. It has glossy green leaves and trumpet-shaped blooms, in bright shades of yellow, orange, salmon, and peach, up to six inches or more in diameter.
With their bright colors, deep throat and bulls-eye shape, the flowers are attractive to pollinators such as butterflies and hummingbirds.
Hibiscus plants need full sun and well-drained soil that stays moist but not wet. They will also grow well in containers. They should receive at least an inch of rain each week. They enjoy hot, humid weather, but when the temp goes above 95 degrees (35 degrees C), they are likely to drop their flower buds, especially if they are not getting enough water. These plants also need to be fertilized twice a month, preferably with a high quality organic fertilizer that contains micronutrients.
If your hibiscus is bothered by pests, such as white flies, aphids or mealy bugs, a strong spray of water may be enough to dislodge them. Larger infestations can be treated with horticultural oil or insecticidal soap.
So what do you do when winter comes? To over-winter your plant, you will need to bring the plant indoors once the temperature drops toward the 30's. Once inside, hibiscus plants will like the same temps that humans enjoy. It won't kill them, but they are decidedly uncomfortable with temps in the 50s! So an unheated garage or basement may not be warm enough.
1. First, remove all spent flowers and any dead leaves or stems.
2. Clean the pot of any debris.
3. Prune the plant and cut the stems back to within 4-5 inches of the trunk.
4. Hose thoroughly to remove insects from the plant.
5. Allow to completely dry before bringing inside.
6. Do not repot in the fall.
7. The plant must be allowed to rest between October and February. Do not do anything to stimulate growth. Allow the soil to become almost completely dry between waterings. Do not let water sit in the saucer beneath the pot. Provide only bright indirect light. These measures will cause the plant's leaves to yellow and fall off, therefore inducing dormancy.
By February to March, your hibiscus will begin to grow new leaves. When night-time temps remain above 55 degrees (13 degrees C), it is safe to put your plant back into the garden. Place in a shadier spot for a few days, then begin exposing it to sun. Begin with an hour a day, then each day increase the amount of sun it receives by an hour until it is ready for its permanent full-sun location. Begin fertiliztion after the hibiscus has been in the garden for two to three weeks.
Many hibiscus plants will never bloom as well after their first winter indoors. If you didn't pay much for your plant or if you don't have room indoors, you may decide to just chunk it when frost arrives, then purchase a new one next year. That way you can be sure you will have plenty of gorgeous flowers each year. 
Hibiscus, tropical hibiscus in summer flowers
Reader Comments (15)
Very handy and helpful information Debs. Nothing like hibiscus blooms to bring a touch of the tropics to the garden!
Dear Deb, Hibiscus were growing well in San Diego, before the climate changed so drastically that is! They were always prone to white fly infestations, but with the very high dry heat that we are having in the recent years, they just don't seem to do so well anymore. I don't grow them for that reason but also because they need a lot of water, which we don't have.
Your two hibiscus look very lovely and your climate in the summer seems to be a good location for them to thrive. Overwintering a hibiscus inside, would be way to much tinkering for me, I certainly would prefer to buy a new one each year.
Wishing you a lovely beginning of summer!
Christina
Your hibiscus are gorgeous - what happy blooms! I've never grown one but I'd bet they'd do quite well here in GA.
Hibiscus are so beautiful, and there's so many gorgeous tropical ones! I have resigned myself to only buying hardy hibiscus, though, as my indoor plant space is very limited thanks to my plant-eating cat. I also like how sometimes they braid the trunk of hibiscus - it's a little different and lovely!
Lovely hibiscus, I have only seen them on holiday to Cyprus. But I found a hardy hibiscus in my new garden so that was a nice surprise, a Hibiscus syriacus, it will be exciting to see what colour the flowers turn out to be and if they are single or double – time will tell :-)
Hi Deb: Thanks for the info. I think people even grow Tropical Hibiscus here in the Midwest (same method of bringing them inside for the winter). Actually, our summers are hot, but not too hot--so very good for Hibiscus. I love Hibiscus, but I don't have any myself because I don't like to have too many houseplants (mainly because of my cats--same issues as Indie). My mom has Hibiscus plants in Florida, though, and she's lucky because they can stay in the ground year-round. Beautiful photos!
Your Hibiscus are beautiful. I usually just sigh and pass by them with longing in my eyes when I see them in the local garden centers. I inherited a hedge of them with our former house but we had horrible problems with the giant white fly so I eventually gave them up. Water is now an issue too but I did fall prey to H. acetosella a few years ago, which requires somewhat less water - it doesn't have the fabulous huge flowers of yours, however.
You have made me realise why my Hibiscus in pots never do well for me. They are house plants for us, I must try again and succeed this time!
Love your Hibiscus Debra. My first encounter with this plant was when we used to holiday in Spain. Dont think I ever saw a yellow one.
I didn't realise you had such a tricky climate. My Hibiscus is lurking in the shade, but I plan to take cuttings and spread those pretty flowers to the sunnier side of the path.
I'd be dropping my buds in triple degree heat. LOL Wimp that I am, I whine when it gets into the eighties.
I don't think I have ever had the pleasure of growing a hibiscus, but I have always admired their trumpet shaped flowers. I particularly like the bright orange-red one. Beautiful!
we're not in a tropical climate but I do see hibiscus plants around. Yours are spectacular.
Thanks for inspiring me to write a blog post on one of my own Hibiscus plants, Deb! :-)
http://www.gardenofaaron.com/2015/06/the-blue-bird-and-purple-coneflowers.html
PS - I gave you props in my blog post...
Didn't know it needed to go dormant in the winter. I have one I put in the greenhouse. The rest stay outside and freeze back to the ground. It takes them until late June to regrow enough to put on buds. I'm expecting some blooms any day now.
I've never grown these but think they're beautiful! I love the variety of deeply saturated colors. :o)