Gardenia

These small shrubs produce highly fragrant creamy-white flowers in summer, 5–10cm (2–4in) across, set against glossy, dark green leaves. As houseplants, they grow to about 45cm (18in) tall, but can grow larger in a conservatory.

Gardenias need bright light, but not strong sun, high humidity and consistently moist, ericaceous peat-free compost. They prefer 21–24°C (70–75°F), with slightly cooler night-time and winter temperatures, but always above 16°C (60°F). They can also be grown outside in summer, in a warm, sheltered spot in partial shade.

Gardenias can’t tolerate waterlogged or dry compost, a hot, dry atmosphere, strong summer sun or deep shade. Most are tender, so must be kept indoors over winter. They dislike large temperature fluctuations, which can cause the flower buds to drop.

Gardenias are acid-loving plants, which means they need an ericaceous peat-free compost, with a pH below 7 – see our guide to soil pH. If you live in a hard water area, then water gardenias with rainwater whenever possible, to maintain the compost’s acidity.