Planting and Caring:
In warmer climates, tropical hibiscus is grown as a perennial garden plant and is used as a woody shrub for hedges and screens. In colder climates, it is often planted in large containers as a patio or deck specimen. Tropical hibiscus can grow as high as 12 or 15 feet, but when brought indoors, it is usually trimmed back to 5 or 6 feet.
Tropical hibiscus is generally free of pests and diseases, but try to maintain consistent soil moisture and air temperature to help prevent yellow leaves. Spider mites and aphids are common insect pests. Plants can develop bacterial diseases due to transmission from insects, rain, and fog; symptoms are leaf wilt, dwarfing, stem rot, and distortion of leaves.
While most plant tags will tell you that tropical hibiscus takes full sun to partial sun, in reality, if you live somewhere hot and bright, you should go more towards a partial sun location. In Northern climates, however, your hibiscus will probably be happier in full sun. If your outdoor plant is consistently producing hibiscus flowers, it is happy, so keep doing what you’re doing. If your plant is not producing buds and flowers, try moving it into an area that has either more or less sunlight.
For growing in a container, use a well-drained potting mix, preferably one formulated for tropical plants. Outdoors, your soil should have lots of organic matter, and it helps to add a layer of compost.
Tropical hibiscus is a thirsty plant and will thrive and produce blossoms only if it is given enough water. Depending on heat, wind, and humidity, your plant may need to be watered daily, or even twice a day in extremely dry conditions. It may need 1 to 2 inches of water per week. However, the soil must be well-drained. If your hibiscus is dropping leaves, or you’re seeing yellowing leaves at the top of the plant, chances are it’s not getting enough water. If your hibiscus has yellowing leaves in the middle or toward the bottom of the plant, chances are it’s suffocating from too much water.
When you buy a potted hibiscus, it likely has a slow-release fertilizer mixed into the soil, so it will not require much feeding in the first few months. After that, regular feeding with a diluted fish emulsion fertilizer will keep it blooming vigorously.