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Growing requirements for hydrangeas

Hydrangea paniculata 'Pinky Winky'
Photo: Lise Servant
 Hydrangea paniculata 'Pinky Winky'


Hydrangeas require little care. They flourish in partial shade or full sun and will adapt to a variety of soil types, as long as they are well drained and remain cool during the summer. The ideal pH is between 5.5 and 6.5. When planting, amend the soil with compost and water regularly to encourage root establishment. Thereafter, simply water during dry periods and add an annual layer of compost to keep them nourished. Mulching helps to retain soil moisture during the summer and provides winter protection for less hardy species. The size varies depending on the hardiness of species and cultivars.


All parts of the plant are poisonous.

Why won’t my hydrangeas bloom?

Often, hydrangeas will “refuse” to bloom. Several factors might be involved: pruning at the wrong time, stems and buds having frozen, pests, lack of sunlight and moisture, inadequate fertilization, etc.

Choose an appropriate site

Hydrangeas bloom very little in the shade, a little more in partial shade and abundantly in the sun. Flowering decreases as light levels decline. Avoid very hot locations and be sure to apply mulch at the plant’s base during the summer to keep the soil cool. To prevent stems and buds from freezing, less hardy species should be planted in a sheltered spot away from winter winds and snow accumulation. At the beginning of the cold season, it is best to cover them with shredded-leaf mulch (30 cm).

Balance fertilization

Plants grown in soil that is too rich produce a lot of foliage, but no blooms. Nitrogen-rich fertilizers applied to flowerbeds or a surrounding lawn will stimulate foliage development but interfere with flowering. Applying a layer of compost annually will provide more than enough nutrition to meet their needs.

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