Hydrangea bushes are blowsy, easy to grow and in tune with today’s gardener’s needs. A few years ago I wrote a blog about them here and, as they are the garden industry’s Plant of the Moment for July 2017, I thought that it was time to revise it!
Hydrangea bushes have an unshakeable link with the Victorian era. You know what I mean, a certain style of house surrounded by overgrown Aucuba, bay laurel, holly and yes Hydrangeas! In these gardens the plants are often the originals that were planted soon after the builders left. How is that for value for money! Hydrangeas are real survivors and will muddle along with just the minimum of attention but given some TLC will do so much better. Add to this the modern improved varieties that have extended the colour range and you have a hardy long living shrub that is easy for a first time gardener but interesting enough to keep the plant connoisseur happy too!
Flamboyant and yet somehow subtle, Hydrangea bushes have everything!
What do Hydrangea bushes like?
Well, whilst they will grow in pretty much any soil and in most situations, they do best where the soil retains moisture but isn’t too wet, where there is some shade but not oppressive dense shade from overhead trees and they enjoy some sunshine but if they get too much are more prone to mildew. Above all they are heavy feeders so be generous in this respect! Apply a general fertiliser such as Vitax Q4 in winter and follow up with summer liquid feeds of Miracle-Gro or tomato feed.
Now, those that look so showy on our sea fronts probably get none of this and yet they put up with [hopefully] wall-to-wall sunshine in summer, strong and often salt laden winds at any time of year and some mediocre soil to boot! Doesn’t that just illustrate how tolerant they are?
What are the main types of Hydrangea bushes?
Mop-headed ball shaped flowered varieties are the most widely grown type and some of these will have originated as forced indoor pot plants that got planted out when the flowers faded. Sometimes this works, but often the varieties selected for indoor pot plants are less hardy than those grown for outside and they often fail to survive the first winter.
The second most popular group is the lacecap group. Here the blooms are flattened with fertile individual flowers forming a necklace of colour around the edge. Some of these take up less space in the garden and so lend themselves to where space is limited. The Swiss ‘Teller’ varieties are exceptionally good and have a good colour range. There are also some excellent Hydrangea serrata varieties and these are especially suited to the smaller garden.
Of course there are many less common species of Hydrangea but gaining in popularity are those with predominantly white blooms. ‘Annabelle’, which can produce blooms that are each larger than a football, is justifiably popular. ‘Limelight’ has white pointed large blooms that are green tinged.
The oak-leaf [H. quercifolia] selections not only have giant ice cream cone shaped blooms but invariably produce some of the very best autumn leaf colour.
A taller growing lacecap which is perfect for a cool north facing wall is either Hydrangea aspera villosa. This has felt-covered leaves and look very unlike other Hydrangeas. They invariably have mauve or even blue flowers and the actual colour will depend on the pH of the soil that they are growing in.
How to get blue blooms
So how do you get any Hydrangea to have those lovely cool looking blue blooms? Well actually you can’t, that is, not every type! Some varieties will do it and others will not and it is the acidity in the soil that enhances this lovely shade. If your soil has a high pH and has lots of lime in it then it might be a struggle [and considerable expense] to treat your soil. If the pH is near to neutral then it is worth applying a blueing product such as Vitax Hydrangea Colourant to each plant annually. Another worthwhile tip is to throw a handful of rusty nails in the bottom of the hole when planting as this can also have the desired effect. Mulching the roots generously every spring will reap dividends and, if that mulch is well-rotted manure, so much the better.
To prune or not to prune, this is something that causes controversy. In my experience it is best to leave any pruning to the end of winter and then just remove the old flower heads. For, under these heads are invariably located the next flower buds, so heavy pruning at this time of year will lead to lots of new growth but little flower! For old plants, more drastic pruning out of whole sections of old wood is necessary. This is best done in mid-winter and will rejuvenate even the oldest plants.
Dried Hydrangea flowers
Finally, fading blooms change colour in the most subtle way. These can be cut and easily dried in a dark airy dry place. A garage is ideal for this giving your Hydrangeas an even greater extended life decorating the house! Here is a short video on a couple of drying methods
You may even wish to spray paint some dried hydrangea blooms to use as Christmas decorations!