Hibiscus is a flowering indoor plant, which can bloom nearly all year round.  It has large, colourful flowers, and is native to the tropics.

Size and growth rate

This plant comes in varying sizes.  The normal height is from 6 inches to 1 foot, but they often grow to as much as 5 feet if not cut back.  They grow quickly with good care and will need a yearly pruning to keep them in bounds.

Flowering and fragrance

Flowers appear where the leaves branch at the top of the stem and bloom for 1 to 3 days, depending on the plant variety.  They have no distinctive fragrance.

Light and Temperature

Hibiscus like the sun and can spend the summer outdoors where the temperatures stay about 65 degrees F.  Its favourite winter temperature is between 50 and 60 degrees F, when it remains dormant.

Watering and Feeding

Water regularly and generously in the growing season, and mist during daylight hours.  Feed with liquid fertilizer at ½ strength during active growth.

Soil and Transplanting

Use humus-rich nutritious potting soil. The best time for transplanting is in early spring.

Grooming

To stop a plant from getting too big, and to enhance its compactness, cut it back in early spring and remove leggy growth.

Propagation

Prepare cuttings by removing to top shoots (3-5 inches long) in spring.  Put them in potting soil and cover them with a plastic bag with air holes in it.  In 3-5 weeks they will develop roots, but until then, do not use fertilizer.  The new shoots should be pinched back to ensure compact growth. If desired, give them a decorative tree shape, but wait to do this until the “trunk” has reached the desired height.

Environment

Hibiscus cannot withstand extreme fluctuations in temperature and humidity.

 

A YEAR WITH YOUR HIBISCUS

February: Transplant your Hibiscus to a larger tub or pot.  Use a good commercial potting soil and gradually increase the amount of water you give your plant, but keep it in a cool spot (54 degrees F) if you let it lie dormant in the winter.

March-April: Raise the temperature to between 68 and 75 degrees F.  Water frequently and add liquid fertilizer.  From now on, leaves and buds will develop rapidly.  You may like to force some blooms by letting the plant dry out a little between watering.

May-October: Dry heat from radiators or forced air will not find favour with your Hibiscus.  Mist it regularly and maintain a constant temperature.  Add liquid fertilizer every time you water it.  Remove withered blooms and clip back leggy growth.

November:  Reduce water and fertilizer gradually and lower the temperature so that your Hibiscus can prepare for its winter rest (unless you want it to keep growing).  Give it as much light as possible and keep watering and feeding, though more moderately than in summer.

December-January: The winter months give your plant time to rest, and the temperature should be lower.

 

CULTIVATE YOUR HIBISCUS TWO WAYS

Let it go dormant over the winter months: The traditional method is to give the plant less food and water in October and November.  Then you cut the plant back and put it in a cool spot. This method yields a profusion of blooms during the plants growth period and none while it is dormant.

Let is grow all year:  To keep it going all year, mist it regularly.  Also, regular watering, feeding and giving your plant as much light as possible. Meanwhile be sure to cut back leggy leafless shoots.

 

PLANT DOCTOR

Aphids: Often to be found at the tips of shoots and on the buds.  They cause uneven curling of leaves or lack of growth.  Check your Hibiscus every time you water it.  Spray with insecticide.

Spider Mites:  Tiny insects that latch on to the underside of leaves.  The leaves develop white or brown spots and finally, they wither and drop off.  You can fight spider mites by removing infested leaves and spraying your Hibiscus with a pyrethrin spray.

Yellow Leaves: Caused by lack of water, or root damage. They may also be the result of over-feeding.

Bud drop: Due to drafts and extreme differences in night and day temperatures, or insufficient light.

Thickened, hard leaves with malformed ribs: Not enough warmth.

This information is also available in a PDF.