How to Grow Carnation
Dianthus caryophyllus
Carnations are classic cut flowers and cottage garden perennials for full sun and well-drained, neutral to alkaline soil. Plant 30cm apart with good air circulation to reduce disease. Pinch out growing tips when young to encourage bushy, multi-stemmed plants. Feed with balanced fertiliser in spring, then high-potash every two weeks when flowering. Deadhead regularly to keep blooms coming from May to August. Cut back by a third after the main flush to encourage a second wave. In cold regions, mulch the crown lightly in winter.
Yearly Lifecycle
Care Essentials
Feed with a balanced fertiliser in spring as growth resumes, then switch to a high-potash feed every two weeks during the flowering season.
Watch For
- Aphids
- Carnation tortrix moth
- Fusarium wilt
- Powdery mildew
- Rust
Companions
Roses, Lavender, Salvia, Gypsophila
Pet Safety
Care Requirements
Light
Full sun; at least 6 hours per day
Carnations need full sun for the best flowering. In shade they become leggy and produce fewer blooms.
Watering
Water at base; avoid wetting foliage
Water regularly during dry spells but ensure excellent drainage. Always water at soil level to avoid fungal disease.
Fertilizing
Balanced feed in spring; high-potash when flowering
Apply a balanced fertiliser as growth resumes in spring. Switch to a high-potash liquid feed every two weeks once flower buds form.
Pruning
Pinch when young; deadhead and cut back after flowering
Pinch out tips on young plants. Deadhead regularly. Cut back by one third after the main flush to encourage a second flowering.
Soil
Well-drained, neutral to slightly alkaline
Carnations dislike acid or waterlogged soils. Add lime to acidic soils and grit to heavy clay. pH 6.5-7.5 is ideal.
Growing Tips
Pinch for bushiness
Pinch out the growing tip above the fourth or fifth node on young plants to encourage branching and more flower stems.
Deadhead for longer blooms
Remove spent flowers to just above a leaf node to prevent seed set and keep new buds forming through summer.
Cut back after main flush
Once the first flush is over, cut stems back by one third to a strong sideshoot to trigger a second wave of flowers.
Good drainage is essential
Carnations rot quickly in waterlogged soil. Add grit to heavy soils and avoid watering into the crown.
Pests & Diseases
Pest Aphids
Identification: Clusters of small green insects on growing tips and flower buds, causing distorted growth.
- Squash by hand or blast off with a water jet.
- Spray with a fatty acid-based insecticide.
- Encourage ladybirds and lacewings.
- Spray with a contact insecticide containing deltamethrin.
Pest Carnation Tortrix Moth
Identification: Leaves spun together with silk threads; inside you find a small green or brown caterpillar.
- Unroll spun leaves and remove caterpillars by hand.
- Apply Bacillus thuringiensis (Bt) spray.
- Spray with a pyrethrin-based insecticide.
Disease Fusarium Wilt Fusarium oxysporum f. sp. dianthi
Symptoms: Plants wilt and collapse despite moist soil; stems turn brown at the base. Affects one stem or the whole plant.
Treatment: Remove and destroy affected plants. Do not compost. Avoid replanting carnations in the same spot.
Prevention: Use well-drained soil. Avoid overwatering and wounding stems. Buy disease-free stock.
Disease Powdery Mildew
Symptoms: White powdery coating on leaves and stems, causing yellowing and reduced vigour.
Treatment: Remove badly affected growth. Spray with a fungicide approved for ornamentals.
Prevention: Space plants well for air circulation. Avoid drought stress. Water at soil level.
Disease Carnation Rust Uromyces dianthi
Symptoms: Orange-brown pustules on the undersides of leaves, with yellow spots on the upper surface.
Treatment: Remove and destroy affected leaves. Spray with a suitable fungicide if severe.
Prevention: Avoid overhead watering. Ensure good air circulation. Remove fallen debris.
Spacing & Planting
| Plant spacing | 30 cm |
| Row spacing | 35 cm |
| Mature height | 55 cm |
| Mature spread | 30 cm |
Space 25-35cm apart for good air circulation. Pinching out encourages branching and more stems.
