Download PDF

Gardenias

Gardenias are among the most popular shrubs in warm temperate, subtropical and tropical gardens. They are loved for their fragrant cream flowers, which appear for many months during warm weather (spring to autumn). These evergreen shrubs have lush, dark green leaves, which can be grown as a stand alone shrub, a low hedge to around 1m high, as a standard (ball of growth on a straight single stem) or as a pot plant.

Check with staff at your local hardware or garden centre to find a gardenia that will thrive in your region

  • Pots, groundcovers and smaller gardens Where a low-grower is needed select ‘Radicans’. This groundcover form is less fussy than larger gardenias and more tolerant of both cold and dry conditions. It can be used to spill over the edge of a garden bed.
  • Shrubs and taller growers The florist’s gardenia (Gardenia augusta ‘Florida’) grows to 1-1.5m high and wide.
  • Taller hedges or standards The taller growing varieties including ‘Magnifica’ and ‘Professor Pucci’, which can reach 2m high.
  • Star gardenia (Gardenia thunbergia) It has tubular flowers that still carry that gardenia fragrance. It tolerates cold winters but can also withstand hot summers. It is native to South Africa while Gardenia augusta is native to southern parts of China and Japan.

Growing conditions

Aspect Gardenias need a sunny location with full sun but tolerate some shade for part of the day. Gardenias grown with too much shade may fail to flower and
can be susceptible to pests such as scale. Use
EarthCare Enviro Pest Oil insect spray to control pests. Spray both sides of the foliage and repeat 14 days later
if needed.

Soil Gardenias grow in a wide range of soils but do best in a neutral to slightly alkaline soil pH (around 6-7) that is deep, moisture retentive. Apply Seasol Super Compost to the soil before planting to aid healthy growth.

Climate Gardenias are part of the citrus family and require the same growing conditions as lemons. They grow in all but the coldest climates but prefer warm climates. In cold areas give protection from winter cold.

How to look after gardenias with PowerFeed
How to look after gardenias with PowerFeed

General care

Watering Adequate and regular watering are important especially in spring and summer. Water regularly if plants are in hot, dry or exposed conditions or if they are growing in containers.

Feeding and mulching Gardenias are fed during the growing season from spring to autumn with a complete fertiliser such as Seasol plus Nutrients Roses & Flowers. Water it in well after application. Plants also benefit from liquid feed such as PowerFeed PRO SERIES for Roses & Flowers during the growing season. Plants in containers can be liquid fed every two to four weeks while they are growing and flowering. Surround plants with organic mulch such as lucerne, sugar cane or straw.

Pruning Gardenias can be pruned to shape. Deadhead throughout the flowering season.

Watch for Generally gardenias are problem-free but may be affected by scale. Fullers rose weevils may chew buds. Thrips may spoil flowers during dry weather. Use EarthCare Enviro Pest Oil insect spray to control pests. Spray both sides of the foliage and repeat 14 days later if needed.

Buds that fail to open may have formed as the weather is cooling in autumn. Yellowing leaves in winter is due to cold weather and soils. The plant is unable to take up enough nutrients. Overcome by liquid feeding as the warm conditions return in spring and increase watering. If yellowing leaves persist liquid feed with PowerFeed PRO SERIES for Roses & Flowers.