Most people know Hydrangeas. Perhaps you remember a Hydrangea plant growing in your grandparents’ garden, or you probably even admire one every day on your way to work. The common Hydrangeas, which we’re used to seeing in the UK, are Hydrangea macrophylla. They have those classical mop-head blooms that look like swimming caps, a rounded habit and glossy, puckered foliage.
They are a pretty easy-to-grow shrub, are usually very hardy and will last for many years. That’s why you can often spot some quite mature specimens in gardens up and down the UK. However, there’s a few simple tips that can help you get even better results from your Hydrangea macrophylla, which I’ll share with you here. Plus, I’ll be giving you a sneak peek of some brand new varieties.
How were Hydrangeas discovered?
Despite being a Japanese native and proving popular in Japan for many years, the Hydrangea did not reach Europe until 1736, when a colonist brought one to England. However, ancient Hydrangea fossils have actually been discovered in North America, and were found to date back over 50 million years..
Hydrangeas have been popular in municipal planting schemes for many years, thanks to their structure and poise. Even when not in flower, they have border presence, and are a wise choice for slightly shaded borders, although not too shady!
Here’s 5 cool facts about Hydrangeas:
- Giving someone pink hydrangeas in Asia is a symbol that ‘you are the beat to their heart’.
- The flower of a Hydrangea macrophylla is a ‘corymb’, with all flowers on a single plane or even displayed as a sphere.
- In Japan, a sweet tea is made from the leaves of the specific species Hydrangea macrophylla var thunbergii.
- Hydrangea macrophylla are classed as having ‘low flammability’, so are authorised to be used in ‘building protection zones’.
- Hydrangea cut blooms are great for giving as a bunch, as the pollen is allergy-safe and the blooms lack fragrance.
So, how can I grow the best Hydrangeas?
They need lots of water!
Well, the name first of all gives us a clue! The name Hydrangea actually comes from the Greek word “hydor,” meaning water, indicting the plant’s thirst, and “angos,” means vessel, referring to the cup-shaped florets.
Your Hydrangeas need plenty of water in order to give you the most jazzy displays. Where possible, plant into a moisture-retentive soil.
In drier soils, you can mixed in well-rotted compost and add a mulch layer in order to lock the moisture into the soil. Alternatively, install a watering pipe sunk into the soil, this can help get more water right down to the roots. When growing in containers, place a saucer beneath the container, so you can keep it topped up. Your Hydrangea will thank you for it!
Don’t cut next year’s blooms off!
Pruning your Hydrangea macrophylla willy-nilly can result in zero flowers… so pay attention..
After your Hydrangea macrophylla plant has flowered, it’s very important to do the right thing. Don’t cut anything off! Leaving the faded blooms on Hydrangea macrophylla can protect the newer growth below those fading blooms from frost damage. So, you must wait. In the spring, you can remove those dead flower heads, cutting back to the healthy pair of buds you’ve been protecting!
How to know what colour your flowers will be
Now, in case you didn’t know, Hydrangeas are pretty cool and they can kinda ‘change colour’! The soil pH (whether your soil is acidic or alkaline) will affect how much aluminium is available to the plants.
An acidic soil will result in bluey-coloured flowers, and an alkali soil can give pinker flowers. If your soil is in-between (neutral), then your blooms will be mauve-blue. It is possible to change the colour yourself by putting additives into the soil too! Some great home remedies include crushed citrus peel, pine needles or coffee grounds (to make your soil around your plants more acidic) and ‘garden lime’ if you want to change them to pink!
Where can you plant your Hydrangea?
Hydrangea macrophylla will enjoy slightly shaded conditions the most, so try to avoid baking hot sun. If you do put them into a sunny position, be prepared to water them a lot more often! Provide a moist, rich soil and plant out, taking into account their eventual size. Hydrangea macrophylla are great for containers too, use a pot at least 12 inches in diameter initially, and pot on every few years as the plants get bigger!
A world of new uses
Despite once being seen as ‘untrendy’, Hydrangeas are now massively popular, not just as a garden plant, but also a cut flower. They have been used in many wedding bouquets, and also dry well for autumn arrangements.
What are your favourite Hydrangeas? Let me know in the comments below!
Michael has been involved with gardening and plants since he was just five years old. He is a self-professed Plant Geek, and was listed in the Sunday Times top 20 most influential people in the gardening world, thanks to his plant hunter role at Thompson & Morgan.
Michael was responsible for new plant introductions such as the Egg and Chips plant and the FuchsiaBerry and keeps busy travelling the world in search of new plants as well as lecturing worldwide, including stints in Japan. He is very active on social media – so why not give him a follow at @mr_plantgeek or Facebook. You can also listen to The Plant Based Podcast with Michael and co-host Ellen-Mary on iTunes, Spotify and Google.