Blog

Early winter is setting in now in the gardens. In spite of all the rain our beech trees are on fire now in a last blaze of orange autumn colour. The Gingko Biloba too is a shining beacon of fine butter yellow. As the green pigment breaks down in the cool and dark of the season, the beautiful autumn colour reveals itself.

Photos: Gingko biloba (left) and Snake Bark Maple, Acer capillipes (right)

There is a slight tension between leaving the leaves for visitors to collect and scuff through as they marvel at their colours, and the professional gardener who knows the damage that rotting leaves can cause to our grass. That said we can only just keep up with the fall so there are plenty to go round.

We have been making some great leaf mould from previous years’ leaf and together with garden compost we use this to condition our soil. High up on the chalk hill at Highdown the soil can be described as thin or very thin and is thirsty for the addition of organic matter.

It is easy to make leaf mould at home and just keep it bagged or covered to retain moisture … and to get the very best, leave it for two years.

The garden borders and shrubbery are also revealing themselves in their winter mode and, unlike us layering up with extra clothes, they divest themselves of their summer attire and sit naked until spring.

Entire borders and areas of the garden are now see through, the woody forms of trees and shrubs laid bare to reveal form and detailed tracery of branch and twig.

Photo: orbus sargentiana

Winter tree identification without leaf or flower to guide you is quite an art and we have been honing ours and our apprentice’s eye for the detail of winter buds and bark.

We are lucky to have some garden plans to help us at Highdown, but as we refine these and delve down into historic records we are often coming up with surprises such as a Paper Mulberry (Bousonetia papyrifera) with its very variable foliage masquerading as a Black Mulberry (Morus nigra).

As the garden sinks into the deep dormancy of winter even now there are signs of new growth and a spring to come. As we winterise our shrub beds and do a final weed and mulch down, the bulbs just below are poised ready for their spring display.

The earliest in the garden is a November Snowdrop (Galanthus nivalis reginaeolgae) blooming away with its elegant flowers hanging on little fishing rod stems on our rockery; it just can’t wait for the New Year.

Photos: Galanthus reginaeolgae

Work on our National Lottery Heritage Fund award is well underway now and autumn is a busy time too for all our plants as they ripen this year’s berries and their seeds within.

Part of our work is to conserve the plant collection both in-situ and by distributing plants and seeds to other botanical collection holders.

Our new Plant Heritage Officer Annelise and Craft Gardener Paul have been collecting seeds from some of our best and most notable trees and shrubs for the Millenium Seed Bank, held by Kew Gardens at Wakehurst Place in Sussex.

The seed bank aims to save plants throughout the world which are most at risk and valuable for the future.

Whilst some of plants are beginning to show some autumn leaf colour our chalky soils do not give the fiery tones associated with more acid conditions as you might for example find in the Sussex Weald. Autumn at Highdown is however notable for its fantastic displays of berries.

Gorgeous orange and red Cotoneaster, coral Spindle berries and shining blue Clerodendron seeds garland our borders in a sumptuous display.

Photo: Red Cotoneaster C.franchetii Sterniana (left) and Clerodendron tricotomum fargesii (right)

There is plenty to go round which is a good job as we compete with Blackbirds and Blue and Great Tits who have begun feasting on the autumn glut.

We have been trained by the Seed Bank to collect, clean and cut test the seed to ensure that they are good, ripe and viable. In the picture you can see the perfect cut seed of our Euonymus grandifloras salicifolius.

We have two large specimens growing on the thinnest of soil near the bungalow and clothed with light pink berries.

Photo: Euonymus grandiflorus salicifolius fruit (left) and cutting one of the seeds open (right)

The seed is then recorded and together with a pressed dried leaf sample for the herbarium are kept in cold storage until they are needed for research or to raise new plants.

We have a great team of volunteers at the garden who help with all manner of horticultural tasks and this week some will be joining us for another training session to help us collect, clean and sort seeds.

We will also be growing some seed ourselves to restock the garden and to distribute to other living collections.

Our Viburnum betulifolium is one of our best berrying shrubs with cascades of bright red translucent berries hanging like redcurrants from its tall spreading branches.

Covered in white flowers in June this is one of the plant hunter E.H. Wilson’s introductions from western China and grown from seed at Highdown all those years ago.

Photo: Viburnum betulifoilum

‌An almost audible sigh of relief came from the dry earth on Highdown Hill this week as the first and most appreciable fall of rain we’ve had for what seems like weeks arrived from the sea.

Our parched lawns greened up overnight and we’ll be cutting again in a few days even as growth slows down and we slide into autumn.

The early autumn has brought with it the fruiting of many plants including some of our lower plants the mushrooms and fungi.

The garden is a living collection and of course relies on a vibrant ecology of which fungi are a vital part. Playing a role as nature’s recyclers they break down dead plant material and make available nutrients for uptake by new generations of plants.

However, they don’t always wait for the demise of a plant before beginning their work.

Some trees at Highdown host fungi which are decomposing the dead heart wood held within their lofty boughs and bole.

The pictures below show examples of two common fungi both harmlessly living on the trees dead heart wood, in this case Dryads Saddle (Polyporous squamosus) on one of our red Horse Chestnut’s and a Ganoderma bracket (Ganoderma applanatum/austral) on one of our National Collection trees Cercis racemosa.

Photo: Ganoderma on Cercis (left) and Dryads Saddle on Red Horse Chestnut (right)

The fungi are present all around us as spores in the air and they usually move into the wood of a tree through a wound. There are barriers within the tree to prevent their spread into live wood. Having spent many years as a Tree Officer it’s often this balance between living and dead parts of the tree that is investigated and decisions about the safety of a tree made.

The Cercis here is actually being killed by another much more aggressive Honey Fungus, Armillaria, that will invade and kill living plants and is quite a pest in parks and gardens.

Parts of our collection are particularly prone to its attack including our Cotoneasters, Berberis, and, because the growing conditions on the chalk are so hard, our older Mock Orange, Philadelphus.

The new Heritage Lottery funded Plant Heritage Officer will be tackling this with us by propagating our collection, beginning with those oldest or most at risk plants and working with other plant collection holders to help conserve the stock of these ‘in captivity’ plants. These in turn can assist in global conservation initiatives like the Millennium Seed Bank that provides a safety net for plants that are threatened with extinction.

On our old avenue of Tibetan Cherry the fungi have an interesting maze-like pattern on their lower side, lending themselves to the name of Maze Gills.

Photo: Maze Gill on Cherry