How to Grow Mandevilla
Mandevilla sanderi
A vigorous tropical climbing vine with glossy dark green leaves and large trumpet-shaped flowers in pink, red, or white that bloom continuously from spring to frost. Grows outdoors year-round in frost-free climates (zones 10-12) or as a summer patio plant in cooler regions.
Yearly Lifecycle
Care Essentials
Feed every 2 weeks with a high-potash liquid fertiliser from spring through autumn to promote continuous flowering.
Watch For
- Mealybugs and scale insects
- Spider mites in dry conditions
- Whitefly under glass
Track your Mandevilla care schedule — pruning, feeding, and seasonal tasks
Start planning freeCare Requirements
☀️ Light
Full sun to bright indirect light
Mandevilla thrives in at least 6 hours of direct sun per day. In the UK, a south- or west-facing wall or patio position is ideal; indoors during winter, place in the brightest available spot.
💧 Watering
Water freely in summer, sparingly in winter
Keep compost consistently moist (not waterlogged) from spring through autumn. Reduce watering significantly once brought indoors; allow the top half of the compost to dry before watering again during the dormant period.
🌱 Fertilizing
High-potash feed every 1-2 weeks in the growing season
Apply a liquid tomato fertiliser or high-potash feed fortnightly from late spring until early autumn. Avoid high-nitrogen feeds, which promote leafy growth at the expense of flowers. Stop feeding entirely once plants are brought indoors.
✂️ Pruning
Hard prune in early spring before growth begins
Cut all stems back to 2-3 buds from the base in late winter or early spring. This stimulates strong new growth that will carry the season's flowers. Pinch out growing tips during summer to encourage branching and more flower buds.
❄️ Overwintering
Bring indoors before 10°C; keep barely moist at 10-15°C
Move containers inside before the first frost, typically late September to October in the UK. Place in a frost-free but cool spot (10-15°C); a heated conservatory or spare bedroom works well. Water sparingly — just enough to prevent the compost drying completely — and withhold all feeding until growth resumes in spring.
Growing Tips
Flowers on new wood
Hard prune stems back to 2-3 buds in early spring to encourage vigorous new growth, which carries all the season's flowers. Without pruning, plants become bare and woody at the base.
Bring in before 10°C
Move containers indoors when overnight temperatures approach 10°C (late September in most of the UK). Even a light frost will blacken foliage and set the plant back significantly.
High-potash feeding
Feed with a high-potash liquid fertiliser (such as tomato feed) every 1-2 weeks from late spring through to early autumn to sustain continuous flowering.
Provide firm support
Twining stems need an obelisk, trellis, or wires to climb. Train new growth early in the season; stems become woody and difficult to redirect once mature.
Pests & Diseases
Pest Mealybugs
Identification: White waxy cottony deposits in leaf axils and along stems; sticky honeydew on leaves.
- Dab colonies with a cotton bud soaked in rubbing alcohol.
- Spray with insecticidal soap or neem oil, ensuring thorough coverage of leaf undersides.
- Apply a systemic insecticide containing acetamiprid or imidacloprid as a drench or spray.
Pest Spider Mites
Identification: Fine webbing on leaf undersides; leaves develop pale stippling and bronze discolouration.
- Increase humidity by misting and grouping plants.
- Spray forcefully with water to dislodge mites, then follow with insecticidal soap or neem oil.
- Apply a bifenazate-based miticide; repeat at 7-day intervals for 3 applications.
Pest Scale Insects
Identification: Brown or tan shell-like bumps on stems and leaf undersides; sticky honeydew and sooty mould.
- Scrape off scales with a soft toothbrush and spray with horticultural oil when plants are dormant.
- Apply insecticidal soap to crawlers (juvenile stage) in late spring.
- Use a systemic neonicotinoid drench to kill crawlers feeding on treated tissue.
Disease Root Rot Phytophthora spp. / Pythium spp.
Symptoms: Yellowing and wilting foliage despite moist compost; brown, mushy roots when the rootball is examined.
Treatment: Remove the plant from its pot, cut away all blackened roots with sterile scissors, and repot in fresh, free-draining compost. Water with a phosphonate-based fungicide drench.
Prevention: Never allow pots to sit in standing water; use a gritty, free-draining mix and a pot with adequate drainage holes. Water only when the top 2-3 cm of compost has dried out.
Disease Powdery Mildew Erysiphe spp.
Symptoms: White powdery coating on upper leaf surfaces and young shoots; affected leaves may curl and distort.
Treatment: Remove badly affected leaves. Apply a sulphur-based fungicide or potassium bicarbonate spray at weekly intervals until symptoms clear.
Prevention: Ensure good air circulation around plants; avoid wetting the foliage when watering and do not overcrowd containers.
Log Mandevilla in your garden — track growth, care, and harvests year after year
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