Winter Gardens at the Hillier Arboretum
The Winter Gardens at the Hillier Arboretum are a relatively new addition to the garden.
I had heard about this new feature in the Sir Harold Hillier Arboretum and it claimed to be the largest of its type in Britain.
It had been sometime since I had last visited the Hillier Arboretum. I used to be a regular visitor there especially when I worked as a senior manager for the world famous Hillier Nurseries.
Indeed that great plantsman and president of the vast Hillier Nursery organisation Sir Harold Hillier was still alive then. And at that time he was still adding to this massive collection of hardy plants!
The thing that I wanted to see in midwinter was of course a winter garden. And by that I mean a garden made up of plants that look at their very best in winter.
Nb. this blog was originally published on my previous business website which no longer exists. I’ve brought it up to date.
Entering the garden
My first encounter with the Winter Gardens at the Hillier Arboretum was a mass of impenetrable Rubus cockburnianus ‘Goldenvale’.
This is an ornamental relative of our wild blackberry.
But unlike our native, this has ghostly white coated purple arching stems. These stems are armed with fearsome thorns that makes this the razor wire of the plant world!
It is easy enough to grow and would be a perfect choice to deter trespassers from entering your property.
However, to maintain the best colour it is necessary to cut all the stems down to ground level at the end of winter. This encourages vigorous new shoots to appear and they have the ghostliest white colour of all!
Needless to say, this pruning requires one to be well armed and well protected!
The Winter Gardens at the Hillier Arboretum is found very close to the entrance and well paved too. Such things are important with the changeable weather we can get in winter.
Apparently the Winter Gardens at the Hillier Arboretum covers 3 acres. However it seemed to be much more compact than that to me.
As you would expect of a world class arboretum, all plant groups are used in the winter garden of the Hillier Arboretum.
I approached the main garden and once again Rubus cockburnianus ‘Goldenvale’ is centre stage.
But this time it’s all the more dramatic for the under-planting of Japanese Black Mondo grass Ophiopogon planiscapus Nigrescens AGM.
This plant combination works really well and is heightened by a contrasting nearby group of golden Calluna vulgaris.
The backdrop is of more conifers which are at their best in winter. These make the winter performers stand out.
A common failing when planting small flowered winter shrubs is to position them without a good background.
The collection of conifers here is huge and scattered all over the whole site.
Sadly on this occasion I was unable to see much of the splendid conifer collection. This is a very big site and conifers are spread over 180 acres.
However I must single out a dwarf mountain pine for special mention.
Some forms of Pinus mugo – such as ‘Ophir’ or ‘Winter Gold’ – are green throughout most of the year. But come winter they change to a bright yellow!
These Pinus mugo varieties are slow growing, medium height and, like so many other plants in this winter garden, good for low maintenance gardens too!
If you think pines are too big for your garden then look to these mountain pines.
Grasses, New Zealand Flax and Bamboo
In front of this backdrop of tall conifers was stiff clumps of straw coloured Elephant Grasses [Miscanthus sinensis]. Earlier these would have had showy feathery blooms waving in the breeze.
New Zealand Flax [Phormium cookianum types] gave a more relaxed look. There’s an amazing range of leaf colours to choose from with Phormium.
Bamboos would not be the first plant that comes to mind when planning a winter garden but here there is a very fine collection of showy ones.
The culms [what we call stems] on some varieties are especially striking!
In winter they look at their best with low winter sun reflecting through them.
Here I found the purple-black culms of Phyllostachys nigra.
Alongside glistening gold culms of Phyllostachys aureosulcata ‘Spectabilis’ with their sometimes kinky stems.
But this is not the only great gold stemmed clump forming bamboo! This has a serious rival for winter colour in Phyllostachys vivax ‘Aureocaulis’.
Removal of the weakest culms, a bit of thinning out and digging out any shoots that appear
away from the main clump is the only maintenance required to grow these versatile plants.
For brilliant screening or informal hedging, bamboos take a lot of beating!
I anticipated seeing bold plantings of coloured stem dogwoods. I’d seen then at Cambridge University Botanic Garden’s winter garden.
There are some fine dogwoods at the Hillier Arboretum and several good forms that I had not seen elsewhere.
But I was reminded that this is first and foremost an arboretum. It’s a massive collection of plants of every kind. It’s not meant to be a landscaped garden!
Naturally there were sensational bushes of Cornus sanguinea ‘Winter Beauty’ glowing yellow, orange and red.
This shrub looks very ordinary for most of the year but shows itself when the leaves fall in autumn. The stems are then revealed and it becomes the focal point of any garden for the winter months.
But another called ‘Anny’s Winter Orange’ looked just as good! It would be a very good substitute.
These Cornus sanguinea types need to be pruned with some care. They are not happy to be cut back hard every second spring in the way that the more common Cornus alba types do.
A more selective and less drastic pruning to remove weak shoots and encourage more vigorous shoots is the way to go here.
More pruning information is available on the RHS website here .
Cornus alba varieties – such as silver variegated ‘Elegantissima’ – have the benefit of good winter stem colour and attractive summer leaves. The variety ‘Sibirica Variegata’ is a stunning form that has superb autumn leaf colour too!
I can’t say that I am a great fan of the yellow variegated forms.
However I have to admit that the green leaf forms of Cornus alba ‘Sibirica’ and ‘Baton Rouge’ have the very best red stems of all! Please note that ‘Sibirica’ is sometimes called ‘Westonbirt’.
Of course there were flowers as well as great coloured stems in the Hillier Arboretum.
Sadly I was just too early to drink in the heavenly scent of Daphne bholua ‘Jacqueline Postill’.
Fortunately, I have this and several other Daphne bholua varieties at home and find this the easiest of Daphne to grow.
Daphne bholua needs a bit of space and grows to 2.5 metres high.
You might think twice about planting one as big close to a winter pathway.
But I can assure you that this where you should plant it!
You should plant this where you can enjoy it from January to March and not have to get to the back of a border to enjoy it!
Witch hazels are beautiful winter garden candidates.
With timely pruning immediately after flowering they can be kept small enough for growing in limited space.
The Sir Harold Hillier Arboretum has a national collection of Hamamelis [one of 14 national plant collections!]
Some of these strongly scented and hardy winter flowering shrubs feature in the Winter Garden.
It is quite remarkable how tough these are since the strap-like flowers merely curl up when it gets cold. Then those petals unfurl again when it warms up!
I liked the look of Hamamelis x intermedia Robert and just wondered whether it was named after Sir Harold’s son Robert.
Tempting though this thought is, I rather think that it is more likely that it is named after Robert de Belder.
He, with his wife Jelena, were responsible for Kalmthout Arboretum in Belgium.
When I last visited that garden I found that the witch hazels were aging and a little disappointing.
I have mentioned Miscanthus grass already and its seed heads are a great winter feature.
At the garden I noticed Russian Sage (Phlomis russeliana) with seed heads that look great in winter. I like seeing them when covered with frost.
Be aware that this plant can be a bit invasive. Since it’s mostly surface rooting it is easily removed.
For a herbaceous perennial I find that it is actually quite good as a ground cover plant since it is an evergreen.
Berries and Fruits
On my visit I discovered that some fruits remained on trees and shrubs. And as yet they had not been feasted upon by winter thrushes.
Most eye catching for me was the sea-buckthorn (Hippophae rhamnoides) with its orange coloured small berries.
If you eat the berries raw you’ll find they have a very strong astringent taste.
A friend who farms sea-buckthorn adds apple juice to sweeten the juice naturally. And the vitamins and anti-oxidant properties make the somewhat sharp taste worthwhile!
Because it is dioecious [male and female flowers on different plants] it is best to plant several.
More on sea-buckthorn here.
Birch trees glistened white in the winter sun with various forms of the Himalayan type Betula utilis outstanding.
A tree that grabbed my attention and that I was unfamiliar with was a lovely Clethra barbinervis.
Many Clethra trees have showy bark but this one was a real beauty.
Sadly it will not be easy to find as a young tree to plant.
The Clethra was outstanding but another interesting tree really caught my eye!
It cast cooling shade in summer and in winter it simply glowed!
Lime trees are espalier trained on a gazebo and are heavily pruned every year.
After this hard pruning the new shoots are a glowing orange colour.
Justifiably called ‘Winter Orange’ [Tilia cordata] they really caught my eye!
This arboretum is a plants person’s paradise and warrants regular visits throughout the year. There’s always something of interest to see here!
Snowdrops and early flowering bulbs add to the winter colour as spring approaches. Few had started flowering at the time of my visit.
Away from the winter garden the heather garden is well worth a visit in winter. There’s lots of colour there.
Was it a great winter garden?
I felt a little disappointed on this visit.
It did not live up to my perhaps too high expectations!
Don’t get me wrong, this is a great arboretum but I found the massed planting that winter gardens demand was lacking.
Other places with Winter gardens
Do you have any favourites?
Do you disagree with my assessment of the Winter Gardens at the Hillier Arboretum?
Which plants do you grow that look good in winter?
I’ve written about great winter flowering shrubs here.
Five of the best scented winter flowers – another blog here.