Frostproof gardenia

Sun

Full sun to partial shade; morning sun and afternoon shade are best in hot climates. Shelter from cold, drying winds.

Water

Keep evenly moist but never waterlogged. Water deeply during dry spells, especially while buds develop; containers need more frequent checks.

Soil

Acidic, humus-rich, well-drained soil, ideally pH 5.0-6.0. Use ericaceous compost in containers.

Height

4-5 ft (1.2-1.5 m)

Spread

3-4 ft (0.9-1.2 m)

Flowers

Fragrant, double white flowers from late spring through summer, sometimes with scattered later blooms in warm climates.

Foliage

Evergreen. Glossy, leathery, dark green leaves held densely on upright branches.

Growth

Slow to moderate

Care needed

Medium

• Deer resistant
• Heat tolerant
• Low allergen
• Fragrant

Northern hemisphere months. In Australia, shift them by six.

Difficulty

Hard

Toughness

Needs looking after

Pick your zone, country, light and whether you have pets.

1. Planting day

   1.6 ft (0.5 m)

2. After 1 year

   2.1 ft (0.63 m)

3. After 2 years

   2.5 ft (0.76 m)

4. After 3 years

   2.9 ft (0.89 m)

5. After 5 years

   4 ft (1.2 m)

About 7 years to full size.

From a typical nursery size, at an average rate for this kind of plant. A rule of thumb, not a forecast.

Cats and dogs

Toxic

Growth rate

Slow

• Water at soil level when the surface begins to dry; avoid repeated drying out followed by heavy soaking.
• Feed with a fertiliser for acid-loving shrubs in spring, following the label; avoid late-season feeding in colder climates.
• Apply 2-3 in (5-8 cm) of organic mulch, keeping it clear of the stems.
• Use rainwater where tap water is hard, particularly for container plants.
• Protect young plants during cold snaps; move containers into a bright, cool, frost-free space before hard frosts.

Pruning. Prune lightly just after the main flowering flush, shortening stray shoots and removing dead or damaged wood. Avoid routine autumn or winter pruning, which can remove the next season's flower buds.

Spring

Plant after the risk of hard frost has passed, keeping the root ball at its original depth.

Spring

Apply acid-loving shrub fertiliser and refresh the mulch.

Late spring

Check soil moisture as flower buds swell and inspect new growth for aphids.

Summer

Water deeply during dry weather and remove faded flowers if their browning petals are conspicuous.

Summer

Lightly shape the shrub after its main flowering flush.

Autumn

Stop feeding and prepare frost protection; move pots under cover before hard frost.

Winter

Keep sheltered container plants slightly moist and check for scale insects and spider mites.

• Plant beside a terrace or entrance where the flower scent can be enjoyed at close range.
• Use as a low, loosely clipped evergreen hedge in warm, sheltered gardens.
• Grow in a large container on alkaline-soil sites, using ericaceous compost.
• Combine with camellias, azaleas and ferns in an acidic, partially shaded border.
• Use the white flowers and dark foliage in a white garden or evening seating area.

Garden styles it suits: Southern, Traditional, Modern courtyard, Sensory garden, White garden and Moon garden.

Plant it with: Camellias, Azaleas, Japanese pieris, Japanese forest grass, Autumn fern and Lilyturf.

Wildlife: Flowers may attract some insects, but the double blooms offer less accessible food than single-flowered shrubs. Dense evergreen growth provides modest shelter for small garden animals.

• Yellow leaves with green veins often indicate iron deficiency caused by alkaline soil or water. Check soil pH, use rainwater and apply chelated iron if needed; grow in ericaceous compost if the ground is unsuitable.
• Bud drop can follow drought, waterlogging or sudden temperature changes. Keep moisture steady, improve drainage and shelter the plant from cold winds.
• Scale insects and whiteflies produce sticky honeydew that supports black sooty mould. Inspect leaf undersides and stems, and treat infestations with a labelled horticultural oil or insecticidal soap.
• Root rot causes wilting and decline in persistently wet soil. Improve drainage, avoid standing water beneath pots and remove badly affected plants.

Toxic to cats and dogs if eaten; leaves, flowers and fruit can cause vomiting, diarrhoea or hives, usually of mild severity. Not known to be toxic to horses. It is not a food plant for people, and ingestion may cause stomach upset; keep it away from children likely to eat plant material.

• Other double-flowered gardenias (Gardenia jasminoides)

  Many cultivars have nearly identical flowers and leaves. Upright habit alone cannot confirm 'Frostproof'; a reliable nursery label is the best identification.

• Crape jasmine (Tabernaemontana divaricata)

  Usually has larger, more prominently veined leaves and pinwheel-shaped flowers, although double forms occur. It is a tropical shrub with much less cold tolerance.

• Sweet olive (Osmanthus fragrans)

  Also has evergreen leaves and powerful fragrance, but its flowers are tiny and clustered rather than large, double and rose-like.

Gardenia honours the Scottish-born physician and botanist Alexander Garden, while jasminoides means jasmine-like, referring to the resemblance of its scented flowers.

Propagation. Take semi-ripe cuttings in summer and root them in a moist, free-draining medium with warmth and high humidity. Seed will not reliably produce plants identical to 'Frostproof'.

Accepted botanical name

Gardenia jasminoides

In the US and Canada

Introduced in Pacific Basin and Puerto Rico.

Native range

Cambodia, China North-Central, China South-Central, China Southeast, East Himalaya, Hainan, Laos, Taiwan, Thailand and Vietnam.

Measured

Average height 300 cm.

Sources: GBIF (CC BY 4.0), USDA PLANTS and Trefle (CC BY 4.0). The care and design notes are LandscapeGPT's own.