Smooth hydrangea
Hydrangea arborescens · Hydrangeaceae
📷 H. Zell · CC BY-SA 3.0
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The gardener's calendar
Smooth hydrangea is in full bloom: enjoy it, watch watering in hot weather and let spent flowers feed pollinators before pruning.
ID card
- Common name
- Virginia sweetspire
- Family
- Hydrangeaceae
- Type
- Deciduous shrub
- Adult height
- Up to 2.5 m
- Flowering
- June to September
- Exposure
- Full sun to partial shade
- Hardiness
- Excellent (-25 °C)
- Origin
- North America
✓ Taxonomy verifiedSource: AI estimate · hardiness: reliability high.
Expert tips
The key tip
Hydrangea arborescens flowers on new wood: cut back hard in March and apply compost to the surface.
The common mistake
Light pruning or pruning in autumn, thinking you're protecting it; this produces late and spindly flowers.
The pro's trick
If the year was cold and winters harsh, cut back to 10 cm from the ground: the plant will bounce back even more vigorously and flowers will be bigger and more abundant.
Care
Watering
Water regularly during the growing season to keep the soil moist but not waterlogged. In summer, increase frequency during prolonged dry spells. Reduce watering in autumn and winter. Mulching helps retain moisture.
Exposure
Plant in full sun for generous flowering, or in partial shade in very hot regions. Virginia sweetspire tolerates indirect light well. At least 6 hours of direct sunlight promotes beautiful blooms.
Pruning and maintenance
Prune in late winter (February-March), before growth resumes. Remove dead wood and cut back stems by half to encourage dense branching. Flowers appear on new growth, so generous pruning stimulates flowering.
Fertilizing
Apply balanced fertilizer in spring when growth begins. During intense flowering periods, monthly applications of mild fertilizer support flower production. Prefer organic fertilizers or those specially formulated for flowering shrubs.
Soil and planting
Virginia sweetspire prefers rich, well-drained soil that is slightly acidic to neutral. Enrich the soil with compost or peat at planting time. It tolerates ordinary soils but develops better in fertile, moist potting soil.
Health and common problems
Generally robust, it may suffer from powdery mildew in humid, enclosed conditions: ensure good air circulation. Aphids may appear in spring on young leaves. Regular watering and good foliage hygiene prevent most issues.
Did you know?
Virginia sweetspire originates from eastern American forests and was introduced to Europe in the 18th century, where it became well established. Unlike other hydrangeas, its flower color remains pure white or slightly pink and does not vary according to soil pH, making it a predictable choice for gardening.
Where to buy it
Best planted in autumn so the roots settle in before summer, or in early spring once the frost has passed. Pick a plant with healthy foliage and roots that are not exposed. Best time: March, October, November.
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Tips generated and checked by Viridia — adapt them to your local climate.