Look forward to spectacular summer blooms with our June A-List gift with purchase

Back by popular demand! Spend €80 in one transaction at our stores in June and get a compact mophead hydrangea in pink, blue, white, or red if you’re a member of our A-List!

When it comes to flamboyant summer blooms, nothing will never surpass the beauty of hydrangeas. Hydrangeas are such reliable flowering shrubs and they suit gardens of all sizes. They flower for much longer than most other plants, months rather than weeks. Many people are unaware of just how many different types and colours of hydrangeas come in. The best-known hydrangeas are the mopheads and the lacecaps, which are traditionally pink or blue depending on your soil pH.

Mophead hydrangeas

Mophead hydrangeas (Hydrangea macrophylla) are the ones with the big showy flowers, which bloom during the summer months and especially during wet summers. One would be forgiven for thinking mopheads were only available in pink or blue, as this is what you tend to see in many people’s gardens. This is not the case and a visit to our garden centres will reveal that they are available in a vast array of colours including whites, reds, and even black-stemmed varieties.

This is the variety of shrub we’re giving away as our June gift with purchase. Your colour options are blue, pink, white and white fringed with red. How do I get the free hydrangea? First step: get the Arboretum app and join A-List.

Download the Arboretum app!

Colour change in hydrangeas

The most common question we’re asked regarding hydrangeas is how to keep blue hydrangeas from changing to various shades of pink. The cause of this strange phenomenon is soil type; alkaline soils cause blue hydrangeas to turn pink, so to prevent it happening you will need to raise the pH level by adding aluminium sulphate to the soil. If you are living in an area where the soil is alkaline, a good option is to grow your blue hydrangeas in pots filled with ericaceous compost. That way, your plant is contained in more acidic soil that will keep the blue colour. Pink and red hydrangeas will generally stay the same colour, as will whites.

Hydrangea care

As a rule, do not prune macrophylla hydrangeas. This is because macrophylla hydrangeas flower on old wood (the previous year’s growth) and pruning them later than July will result in no blooms the following year. One exception to this is Hydrangea arborescens ‘Annabelle’, a late-summer-flowering hydrangea that flowers on the current season’s growth, therefore it can be pruned back hard in the winter. You may prune damaged stems, of course, and to rejuvenate plants that are five years and older. In this case, prune back a third of the older stems each summer to keep the plants actively growing.

To be successful with hydrangeas you must plant them in soils that can retain moisture. This is especially important during dry summers – they are thirsty plants! They are happiest when they receive morning sun followed by afternoon shade.

Are there other types of hydrangea?

Hydrangea anomala petiolaris is a climbing plant that is perfect for covering a shady north or east-facing wall, fence, or house wall. It typically sheds its leaves in winter after turning yellow in autumn. Initially, it will need wires or a trellis, but after a season or two, it will produce self-clinging roots.

Hydrangea Paniculata

The panicle varieties of hydrangeas are known for their almost pyramidal flowerheads, unlike the round flower heads of mophead and lacecap hydrangeas. Panicle hydrangeas thrive in direct sun and can also grow well in partial shade. They require moist, well-drained, fertile soil. Similar to Hydrangea arborescens, panicle hydrangeas flower on the current year’s growth, so they should be pruned in early spring.

Lacecap hydrangeas

Lacecap hydrangeas (Hydrangea macrophylla normalis) are less flamboyant than the mopheads but tend to be more delicate looking and fit in better with natural woodland gardening. Once again, the lacecaps come in a huge variety of colours, ranging from pinks and purples to blues and whites.