Have you been led to believe that the Hibiscus is one of those dramatic plants that’s super easy to grow indoors? Don’t fall for it. Hibiscus care indoors can only be done with one species and that’s the Tropical variety.
Some call it the Chinese Hibiscus because they believe it’s native to China, but others believe it to be from farther afield in the Far East. Regardless where the plant’s native origin is, it is only the Tropical Hibiscus that can be successfully container grown indoors.
The other two species are the Perennial Hibiscus and the Hardy Hibiscus. None of those are suited to indoor growing. Even outdoors, these varieties will only bloom from summer through to Fall.
The same happens with the Chinese Hibiscus, but there are steps you can take to encourage this species of plant to bloom and control when it does.
Each bloom is short lasting only a day to two days. With the right care and attention, you can take great delight in watching the blooming process with anticipation and excitement, wondering if the next bloom will be a single, or a double-bloom, what colors the petals will be and what the Corolla color will be.
Every bloom is different, takes a few days to fully open, stays for a few days before closing, then the cycle repeats throughout its season.
With the right Hibiscus care, indoor-grown Chinese Hibiscus plants can be in bloom over the winter. They only need a few months rest, the rest of the year they can flourish, often to the owner’s delight.
Let your Hibiscus brighten up your home by giving it the attention it needs to really start showing off.
The Pampering Your Hibiscus Plant Really Needs
For Hibiscus care indoors, these plants will need more attention than most other houseplants. The payoff is worth it.
Sunlight (and lots of it!)
The Chinese Hibiscus needs at least six hours of full sun daily. This is difficult to achieve indoors, regardless how sunny of a spot you have available, and even at that, the sunlight is going to be filtered so it will need as much as it can get.
The less it gets, the less it blooms so if you’re finding you’re unable to get your Hibiscus to bloom indoors, there’s a good chance it’s because it’s positioned in a spot with too much shade. Try a sunnier spot, (south-facing windows are usually ideal) or an alternative, although pricier, is to mimic sunlight with indoor grow lights.
If you do need to replicate full sun, an option to explore is using fluorescent lighting. The more tubes the better. To encourage growth and bloom, they’ll need between 12 to 16 hours light per day. But, do remember that they need a rest period too. October to February is ideal for dormancy.
The ideal temperature to maintain is between 50oF (10oC) and 60oF (15.5oC)
In the winter months when temperatures are dropping, especially overnight, it may be that a small heater is required to maintain the room temperatures. In the summer, air conditioning and ventilation can be used to cool the room down.
When temperatures drop below 30oF (-1oC), it’s likely to kill a hibiscus.
Surprisingly, for a tropical species of plant, the Hibiscus doesn’t do great in heatwaves. When temperatures soar to 90oF and higher, leaves will yellow and droop and you can also find leaf drop becomes a problem.
Preferable temperatures for a Hibiscus indoors are above 60oF and below 80oF.
How and When to Water Hibiscus
Hibiscus plants are thirsty a lot. That’s why they need more care and attention than most regular houseplants.
The larger the plant and the warmer the room, the more water you’ll need to feed and more often too. The only way to know when to feed it is to consistently check how moist the soil is. Hibiscus plants need to be watered before the soil dries.
In the summer months is when you really need to be careful with watering Hibiscus plants.
Damage happens every time the plant wilts and it does that every time it gets thirsty. The more it happens, the less growth and blooms you get. Watering needs to be done before the soil around the roots of the plant get too dry.
It’s also recommended to water the roots of the plant and never water over it as that can encourage plant diseases because of the high moisture level. In other words, make sure it always has moist soil, but never wet leaves.
The leaves should always be dry, a deep green color, and never wilting.
Humidity is a Necessity
Indoors, whatever you use to heat your home is going to dry the air. A lack of humidity indoors can cause bud and leaf drop on Chinese Hibiscus plants.
As these are tropical, they do well with high humidity. In greenhouse conditions, they can cope with humidity levels as high as 90%. Indoors, do not try that.
A healthy range for indoors, according to Mayo Clinic is between 30% and 50%. For a hibiscus, the higher the better. For you, as high as you can comfortably tolerate. A dehumidifier is the most accurate way to control humidity indoors.
An alternative to a dehumidifier is to use a plant humidifier tray to create a damp microclimate under the soil so that the water consistently evaporates, increasing the humidity levels around the plant only, rather than the entire room.
Hibiscus are heavy feeders and need a frequent dose of balanced fertilizer.
A 20-20-20 or other balanced fertilizer should be used twice per month during the growing season when it’s outdoors. Once you bring it indoors, reduce the frequency to once monthly and apply at half the usual strength until October when it’s best to let the plant rest and start feeding it again around late February.
Your Two Pruning Options
Pruning is done to stimulate growth and to keep things under control. If you don’t cut a Hibiscus back, it can keep growing to a height of 15 ft, possibly higher. Not ideal for indoors.
Indoor growers have two options they can choose for pruning. Either go all-in around February and prune every branch back by two-thirds, or go slow-and-steady by regularly trimming back longer branches by two thirds at a time.
The latter option will mean the plant can have a longer bloom season. If you take it all back it once, you’ll have more blooms at once.
Timing the Move!
This is super important to avoid over stressing your plant. Don’t leave things until right before the end of the summer before you bring your plant indoors. By that time, the humidity levels are higher outdoors and the temperatures far lower.
Leaving things too late to move your plant will shock it. In response, you’ll need to contend with yellowing leaves and bud drop with a high likelihood of less blooms next season.
Instead, plan to move your Hibiscus indoors around August. Monitor temperatures so that you’re moving your plant when the conditions between outdoors and indoors are as close a match as possible.
Winter Care Begins with Hygiene
In the warmer weather, Chinese Hibiscus look gorgeous on the decking or patio areas, bringing color to the garden. And they do need that spell outdoors to take advantage of the warmer weather, and brighter sunlight.
They’re best brought in before the end of the summer though but when you do, hygiene is crucial to make sure there’s no pests lingering anywhere in the soil, or on the leaves.
Spider mites are one pest that’s attracted to the warmth and dryish topsoil of Hibiscus and they will multiply and thrive given the chance, so take care to eliminate any pests by showering or bathing your plant outdoors before you bring it in.
To wash these thoroughly, use a garden hose spray. Not a watering can with a super soft pour.
This will need repeating two to three times weekly over the course of two to three weeks to make certain that any pests are washed away and any eggs that hatch are gone before you bring the plant indoors.
Once inside, it’s a breeding ground for any lingering pests and since your plant will be under some stress from being acclimatized and then moved indoors, any further stress has a lot more potential to damage it, possibly killing it.
After a few weeks of repeatedly showering your Hibiscus, for the last treatment, it’s advisable to add a horticultural oil to the water.
Studies have found that applying a horticultural oil to plants is effective at controlling pest insects and limiting the potential of some plant diseases. These are pesticides and there are some that are petroleum based and others that are plant-based.
Examples of natural products are cottonseed and soybean oil. Both oil-based and plant-based pesticides work the same way. They’re thick enough to suffocate most insects that can attack plants.
The most crucial steps for Hibiscus care indoors are to provide enough light, maintain a consistent temperature above 50oF and high humidity with consistent watering at the root zone because the instant the soil around the roots become dry, it disrupts the plant’s growth cycle and kills it a little bit each time.
Keep the soil moist, give it plenty of light, keep it warm, feed it plenty and don’t be afraid to take the pruners to it! It will reward you with colorful blooms for longer.
Growing up with a mom who filled her home (inside and out) with all sorts of plants, Lisa got her start in gardening at a young age. Living now on her own with a home and yard full of plants (including an indoor greenhouse), she shares all the gardening tips she’s gained over the years.