China Rose, hibiscus rosa sinensis

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Evergreen indoors and flowering from March right through to November, China rose (Hibiscus rosa sinensis) is the exotic hibiscus grown in pots at a modest 1⅓ to 5 feet, though it reaches 13 feet in the wild. Give it a well-lit spot that never freezes and it blooms for months on end.

They are plants that boast rare beauty and bloom over an extended period of time. In our latitudes they are mostly grown as indoor plants, however they can be grown outdoors wherever the climate permits, that is, as long as it never freezes outside.

Planting and re-potting of China rose

If the China rose you have just purchased is already bearing flowers, do not re-pot the plant because this may disturb it. Hibiscus rosa sinensis likes feeling a bit tight in its pot.

• Repotting China roses is generally performed in March, before plant growth resumes.
• Choose a pot that is slightly larger than the previous one.
• Place at the bottom of it a bed of gravel or clay beads to ensure drainage.
• Ideally, prepare one part soil mix and one part heath.

If you wish to grow your China roses outdoors, it must not freeze in your area. Growing outdoors is only possible in zones with mild or tropical climates.

• Choose a sun-bathed area, sheltered from stronger winds.
• Plant your China rose in a mix of garden soil, soil mix and heath.

If it freezes in your area, choose a different hibiscus variety, althea or rose mallow.

Propagate China roses through cuttings in spring or summer.

Caring for and pruning China Rose

Your China roses will be all the more beautiful and full of flowers if you prune them at the beginning of spring.

• Prune lightly, focus on remodeling the silhouette delicately in March.

During the growth phase, add flower plant fertilizer to spur vegetation and ensure that your China roses will bloom spectacularly.

• Both plants called “China rose” — Rosa chinensis and Hibiscus rosa-sinensis — flower on current-season growth, so pruning before the growing season encourages new shoots that carry the blooms.
• Make each cut just above an outward-facing bud, so the new shoots grow away from the centre and keep the plant open.
• While shaping, cut out dead, spindly or crossing stems, taking them back either to the base or to a healthy bud or side shoot, so light and air reach the plant’s centre.
• For many soft-stemmed houseplants, pinching out the tips of long shoots during active growth encourages branching; bare lower stems, however, usually signal too little light, which pinching alone will not fix.
• Reduce or stop feeding when the plant itself slows down or goes dormant rather than simply when flowering ends, because unused fertiliser salts accumulate in the pot while roots take up little.

Watering China rose

Watering China roses in fall and winter

When your hibiscus has entered dormancy, start reducing water input to match ambient temperatures.

• The cooler it is, the less water a plant needs.
• Conversely, if temperatures hover around 65°F (18°C), it will be necessary to water more.

Watering China roses in spring and summer

This is the period when water needs are the highest.

• Watering once or twice a week should be enough.
• It is crucial to not drown roots and let the ground dry off before watering again.

Empty the saucer under the pot soon after each watering, since potted plants left standing in water are prone to waterlogged, poorly aerated soil, which can lead to root rot.

Diseases and parasites that attack China rose

China rose leaves start to wither and leaves turn themselves inside-out:

• This is often due to excess heat or exposure to the sun is too strong.
• It may help to place the pot in a basin of soft or non-hard water for a short while and then drain it out.

Hibiscus rosa sinensis leaves are sticky and pasty and little insects invade leaves:

• This is an aphid attack, here is how to fight them.

Flower buds fall off before blooming;

• This is often related to excessive air dryness.
• Avoid setting the plant near a radiator or an overly exposed window.
• Place the pot on a bed of gravel or clay pebbles doused in water.

Leaves are covered with a white cottony felt:

• This is most probably an attack of scale insects, here is how to fight scale insects and treat the plant.

Leaves drop off unexpectedly and suddenly:

• This is connected to excess water. Wait until soil surface is dry before watering again.
• Avoid cold breezes or sudden changes in temperature.

Reading the symptoms: what your China rose is telling you

Most China rose troubles show up on the leaves or the buds, and each sign points to a different cause. Use the table to match what you see with the likely explanation and the fix.

Watering and air moisture explain most of these signs, so adjust those first before reaching for a treatment.