Hibiscus rosa-sinensis

Hibiscus requires bright, humid conditions with good ventilation

The introduction of outdoor air into a space, for example, a greenhouse. This airflow can reduce temperature, replenish the gases absorbed by plants and keep down fungal diseases like grey moulds. , protected from direct sunlight and a minimum night temperature of 7ºC (45ºF). Plants can be placed outdoors in summer but need to be brought indoors before temperatures drop below 12ºC (59ºF).

Spring and summer

• Re-pot in February or early March using a peat-free, ideally one formulated specifically for houseplants. Soil based compost
  Can refer to either home-made garden compost or seed/potting compost: • Garden compost is a soil improver made from decomposed plant waste, usually in a compost bin or heap. It is added to soil to improve its fertility, structure and water-holding capacity. Seed or potting composts are used for growing seedlings or plants in containers - a wide range of commercially produced peat-free composts are available, made from a mix of various ingredients, such as loam, composted bark, coir and sand, although you can mix your own. such as John Innes No 2 are also suitable
• Increase watering as the increasing light levels and temperatures stimulate growth
• Begin feeding weekly with a balanced liquid fertilizer for house plants, about six to eight weeks after re-potting

Overwintering

• A warm, humid glasshouse with minimum night temperatures of 7-10ºC (45-50ºF) is ideal, but a warm conservatory or south-facing windowsill will suffice
• Avoid placing plants near open fires, radiators or draughts and move away from windows in frosty weather
• Increase humidity
  The concentration of water vapour in the atmosphere. This affects the rate at which plants transpire (lose water from their leaf pores), which in turn affects how much water their roots absorb from the soil. If air humidity is low, plants transpire quickly and become at risk of wilting if water is lost from the leaves faster than it can be absorbed by the roots. Different plants require different levels of humidity to thrive. Many tropical houseplants need high humidity and are best grown in a steamy bathroom, misted regularly or placed on a saucer of damp pebbles. In a greenhouse, humidity can be raised in hot weather by damping down (wetting) the floor or overhead misting. by placing the plant on a tray containing damp gravel or clay pellets. Plants can be grouped together to maintain a humid microclimate
• Reduce watering as growth slows and only water when the top layer of compost is dry. Cease feeding
• In cool conditions plants will overwinter in a semi- dormant
  Dormancy refers to a period of inactivity in plants, during which they slow down or stop their growth, conserving energy and resources. This is a natural process that helps them survive harsh conditions, such as winter or drought. Dormancy in seeds is a mechanism that prevents them germinating until environmental conditions are favourable for growth. condition

Plants can be kept small and bushy with regular pruning and may live for up to 20 years.

• Shorten the previous season’s growth in February or early March to leave a framework from which new flower-bearing shoots will develop. Stronger growth can be reduced to 4-7 cm (2-3in) from the base
• Remove thin unproductive shoots and prevent overcrowding
• Trim the tips of young plants to encourage bushiness

Softwood tip cuttings or semi-ripe cuttings taken in late spring or early summer, root readily;

• Dip 7-10cm (3-4in) long cuttings
  A method of growing new plants from parts of an existing plant, such as sections of root, stem, leaf or bud. When prepared correctly and planted in the right conditions, they can produce roots and eventually become independent plants. There is a wide range of different methods for taking cuttings, depending on the plant and time of year. in rooting hormone
  A commercial product, usually containing natural or synthetic plant growth hormones and fungicide, that can help to stimulate root production in cuttings. Coat the base of the cutting with the powder, liquid or gel, and insert into moist potting compost. With some plants, such as dahlias and lobelia, cuttings rarely root without rooting hormone, but with others, such as coleus and lavender, cuttings root so readily that it isn’t required. and insert into trays or pots of sandy cutting compost
  Can refer to either home-made garden compost or seed/potting compost: • Garden compost is a soil improver made from decomposed plant waste, usually in a compost bin or heap. It is added to soil to improve its fertility, structure and water-holding capacity. Seed or potting composts are used for growing seedlings or plants in containers - a wide range of commercially produced peat-free composts are available, made from a mix of various ingredients, such as loam, composted bark, coir and sand, although you can mix your own.
• Ideally use a heated propagator
  A heated propagator is a portable heated structure with a vented lid and adjustable, constant, thermostatic temperature control. It provides a warm, humid environment to help seeds germinate and cuttings to root quickly. , although placing pots within plastic bags in warm windowsills can be effective
• Provide bottom heat of 24-27ºC (75-80ºF) and high humidity
  The concentration of water vapour in the atmosphere. This affects the rate at which plants transpire (lose water from their leaf pores), which in turn affects how much water their roots absorb from the soil. If air humidity is low, plants transpire quickly and become at risk of wilting if water is lost from the leaves faster than it can be absorbed by the roots. Different plants require different levels of humidity to thrive. Many tropical houseplants need high humidity and are best grown in a steamy bathroom, misted regularly or placed on a saucer of damp pebbles. In a greenhouse, humidity can be raised in hot weather by damping down (wetting) the floor or overhead misting. to encourage rooting in about two weeks
• Pot rooted cuttings in 9cm (3½in) pots and leave undisturbed over winter

Unfortunately houseplants are not reliably listed in the RHS Plant Finder, as stocks offered in garden centres tend to be sourced abroad making it difficult to identify availablity. Also the range of available Hibiscus rosa-sinensis cultivars is continually changing with new introductions, so it is difficult to make recommendations.

For a variegated

Variegated means having leaves or other plant parts with streaks, blotches or patches of different colours. Typically, these would be a combination of two colours, such as green and gold or green and white. form, consider Hibiscus rosa-sinensis ‘Cooperi’ (v) AGM, a compact plant with heavily marbled olive-green and white leaves, sometimes tinted pink and bearing red flowers, height 1-2m (3-6ft)

RHS Find a Plant

Generally trouble free but may suffer from common glasshouse pests such as aphids, red spider mites and glasshouse whitefly.

Flower buds

A bud is a small, undeveloped shoot that contains the potential for new growth. Buds are typically found on stems, where they can be apical (found at the tip) or axillary (found between leaf axils) and may develop into leaves, shoots or flowers. and leaves turn yellow and drop in winter when light levels are low indoors but plants can survive in this semi- dormant

Dormancy refers to a period of inactivity in plants, during which they slow down or stop their growth, conserving energy and resources. This is a natural process that helps them survive harsh conditions, such as winter or drought. Dormancy in seeds is a mechanism that prevents them germinating until environmental conditions are favourable for growth. state if watering is reduced.