Monthly Masterclass: January

Do it: Prune Ornamental Trees

Dead wood, Winterbourne House and Garden, Digging for Dirt

Most trees won’t need regular pruning but dead wood like this does need to be removed

Step 1

Most ornamental trees will not need regular pruning. However, some remedial work may occasionally be required to address misshapen plants, reduce encroachment onto other plants or structures, and remove dead, dying or diseased wood. Many deciduous trees will benefit from being pruned in the winter although there are notable exceptions. Flowering cherries, for example, are best pruned in April when silver leaf spores are not so prevalent, whilst birches bleed heavily if not pruned in late summer or early autumn. It is therefore necessary to correctly identify your tree before any pruning takes place.

Bad tears can be fatal, Winterbourne House and Garden, Digging for Dirt

Bad tears can be fatal

Step 2

Smaller branches can be pruned with your free hand supporting the weight of the material which is to be removed but larger branches may need to be taken in sections. Always make an undercut first followed by an overcut just beyond, further away from the tree. This will prevent bark from tearing as the branch falls. Once the weight of the branch has been removed in this way the remaining stub should be cut in line with the branch collar, sloping away gently from top to bottom to account for the widening girth of the tree, and to help shed water from the wound.

Epicormic growth, Winterbourne House and Garden, Digging for Dirt

Epicormic growth should be removed as soon as it appears

Step 3

Even when pruned at the correct time many trees will continue to bleed before healing. This bleeding rarely has any serious impact upon the health of the tree and should simply be left to heal naturally over time. Some species will also produce lots of whippy stems around the cut surface called epicormic growth. These weak additions should be removed with secateurs which should then be sprayed with an appropriate disinfectant after use, in order to stop the potential spread of disease, as should the saws used to remove the original branch.

Grow it: Aucuba

What: Aucubas are evergreen shrubs, the most commonly grown of which is Aucuba japonica ‘Variegata’.  The species is a native of Japan where it forms the evergreen under-storey of woods and forests, much as holly does in this country.

Where: Aucubas can withstand dark, dry conditions; indeed the one thing they cannot stand is water-logging. These versatile shrubs can also grow in containers, and will tolerate bright light, though they prefer dappled shade.  Victorians even used smaller strains as potted house plants.

How: Choose the appropriate Aucuba for your garden situation. They will stand some pruning but you risk stimulating ‘water shoots’ (large stems and leaves) which negate the original intention of pruning. Some are used as hedging but if trimmed with sheers the cut leaves can be unsightly.

Aucuba japonica 'Golden Spangles', Winterbourne House and Garden, Digging for Dirt

Aucuba japonica ‘Golden Spangles’ in the Winter Garden

When: Cuttings are best taken in late August or September, a 10 to 15cm stem broken off with a heel is ideal, whilst planting should ideally take place in spring or autumn. However, if care is taken these easy-going shrubs can be planted out any time when the soil can be worked.

The Gardener’s Verdict:

“In the wild the leaves of Aucubas are normally plain green, but several variants have been selected and propagated over the last 150 years, giving rise to a wide variety of leaf shape, size and patterns of variegation.

Aucubas are dioecious, meaning that plants are either male or female. Seedlings can be raised from berries borne on female plants which ripen bright red (the white or ivory fruited cultivars are now very rare) in March and April. A seedling plant will not come true to either parent, so named cultivars must be propagated by cuttings.

Personally, I prefer berries borne on cultivars with plain green leaves such as A.j. ‘Rozannie’, a reliable fruiter growing to about 1m. A popular variegated berrying cultivar is A.j. ‘Crotonifolia’. But beware! Nursery and garden centre labels are not always correct; I would never buy an Aucuba labelled ‘female’ unless I could see female flowers or berries on it.  I have even seen male and female plants sold in the same pot!

For me, the most interesting variegation is displayed by A.j. ‘Sulphurea’ and A.j. ‘Picturata’, though the latter has a tendency to revert.  The leaf shape of A.j. ‘Dentata’ makes up in beauty for its reluctance to berry, and I believe that A.j. ‘Salicifolia’ with or without berries could even substitute for bamboo in some places.

Aucubas, having been out of fashion for some time, are maybe making a come-back as gardeners recognise how varied and easy-going they are. They mix well with herbaceous plants and other shrubs, and brighten the darkest corner even in winter.”

Linda Eggins, Curator, Plant Heritage National Collection of Aucuba japonica held at the University of Birmingham

Read it: A Seasonal Affair

This autumn has seen further changes to the Winter Border as overgrown and congested shrubs have been cleared to make way for some exciting new additions. December’s ‘A Seasonal Affair’ reveals the inspiration behind the new scheme and profiles some of the plants you can expect to see planted there in the spring.

Japanese quince, photograph by Leighanne Gee, Winterbourne House and Garden, Digging for Dirt

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