Hydrangea planting, care & varieties

Hydrangea is without doubt a beautiful flower-bearing plant.

Key Hydrangea facts

Name – Hydrangea
Family – Hydrangeaceae
Type – shrub

Height – 3 to 6 ½ feet (1 to 2 meters)
Exposure – part sun and shade

Soil: soil with heath   –   Foliage: deciduous   –   Flowering: end of spring → fall

Easy to grow and to care for, hydrangeas are amazing all summer long with their magnificent flowers in hues from pink to blue. Moreover, it’s one of very few shrubs that thrive in full shade!

• Find our articles and pages related to hydrangea
• Another name for this shrub is Hortensia.

How to plant hydrangea correctly

Hydrangeas are best planted in fall. Heath-amended soil is mandatory for this plant, especially if your soil is otherwise chalky.

Choosing a partly shaded spot is enough to guarantee magnificent flowers and give your shrub the best it needs to develop harmoniously.

For plants that have been purchased in pots or containers, it’s possible to transplant until spring and even summer as long as both hot and cold spells are avoided.

If you are hoping to see your plants grow large and wide, plant them 30 to 40 inches (80 to 100 cm) apart.

• Check our page on the best way to plant heather plants

Indoor hydrangea

At the end of winter, it’s possible to purchase hydrangea in pots. Their beautiful blooms will decorate your home.

Caring for indoor hydrangea

• Choose a rather cool and well-lit spot, but not in direct sunlight.
• If the temperature exceeds 70° F (21° C), the plant may stop blooming.
• Water so that the soil mix always stays moist but without drowning the roots.

After flowering, what are the options?

• If you don’t wish to plant it outdoors in the ground, don’t plan on keeping it, it won’t bloom again.
• What’s best is to plant it directly in the ground in good heath soil towards April or May and it will bloom again the following year.
• With the pot-in-pot technique, you can coax it into blooming again. Conveniently, you can transfer it back indoors in fall while it’s still flowering!

Pruning and caring for hydrangea

Even though hydrangeas are very easy to care for and practically don’t need any attention, an annual pruning will significantly boost blooming.

• After flowering, remove wilted flowers regularly (deadheading).
• Prune hydrangeas after freezing is over, in March.

Good idea: keep a few flowers on the shrub; they’ll dry out and make fantastic dried-flower bouquets for Christmas.

• For further guidance, refer to our page on pruning hydrangea.

Let’s hear the advice of Hubert Buquet

Master Gardener in the renowned Valloires Gardens, in France

Diseases and parasites that attack hydrangea

Hydrangeas are rather sturdy, but there are a few weak points that open the door to diseases.

If white balls appear along the stems, you are certainly facing an invasion of hydrangea scale insects.

• Scale insects – techniques and organic treatments to avoid them

If whitish felt covers the underside of leaves, it is surely an attack of powdery mildew.

• Powdery mildew – techniques and organic treatments to avoid it

If your soil is too chalky or alkaline, your hydrangea may sag and show signs of exhaustion, and leaves will turn yellow.

This is a form of chlorosis.

• To correct this, fertilize the soil with special hydrangea fertilizer. Additionally, spread as much heath as possible onto the surface of the soil. Mulch with pine bark to reduce pH a bit.

Spots appearing on hydrangea leaves might result from a Septoria infection. Hydrangea is one of the plants septoria infects.

• Learn all about Septoria and how to treat this fungal disease.

Types of hydrangea

Hydrangeas differ in so many ways! For one thing, there are nearly 80 classified species, and each has hundreds of cultivars or varieties. Those most commonly found in gardens are shown here:

• Hydrangea macrophylla – also called bigleaf hydrangea
• Hydrangea petiolaris – a wonderful climbing hydrangea

Every year, new hydrangea varieties appear that are always more unique!

All there is to know about hydrangea

They are found in most gardens and appear almost all over the planet.
Native to Asia, they generally bloom from the beginning of summer to the end of fall.

With the exception of specific white-flowered varieties, the color of their flowers depends on the acidity of the soil where the plant has its roots.

The more acidic the soil, the bluer the flower. Any hydrangea planted in pure heath will almost certainly bear stark blue flowers. Liquid-form aluminum sulfate will also help your hydrangeas’ flowers to turn blue. Lastly, another great way to turn your hydrangea blue is to apply slate mulch, which naturally releases alumina.

Pink to red are the colors for more neutral or chalky soils. If you want to turn your hydrangea from blue to pink, try adding shale mulch.

If you wish to decorate a north-facing wall, train a climbing hydrangea.