Planning for the Autumn Part 2

By Lorraine Spooner

Following on from Part 1 of the ‘Planning for Autumn’ blog which focused on ‘The Right Plant in the Right Place’, this week, Part 2 provides plant recommendations for different soils with a particular emphasis on autumn colour.

Planning for the Autumn Part 2

Clay soils

A heavy clay soil is often viewed with despair by the gardener, but once this type of soil has been improved with organic matter to break up the particles, clay soil benefits from the ability to retain nutrients and water, the perfect ingredients for healthy plant growth.  Some plants may be slow to establish in these conditions, but be patient, once the roots have penetrated the soil, aeration and drainage are improved.

Liquidambar styraciflua ‘Worplesdon’

The sweet gum tree is one of the best for autumn colour, the multiple shades intensifying through the season eventually falling to display a vibrant carpet on the ground below.  ‘Slender Silhouette’ is a good variety to choose where space is limited.

Planning for the Autumn Part 2
Planning for the Autumn Part 2

Betula utilis var. ‘Jacquemontii’

Primarily grown for the stunning bark, which provides such interest in the winter garden, the foliage turns a buttery yellow in autumn adding to the attributes of this deservedly popular tree.  Pictured is a multi-stemmed form which is currently available in a variety of sizes and looks spectacular as a focal point set against a green backdrop.

Planning for the Autumn Part 2
Planning for the Autumn Part 2

Magnolia x soulangeana

It is the huge goblet shaped flowers on this shrubby tree that gives rise to one of its common names – the saucer magnolia.  The white, pink and purple blooms vary between varieties and often appear before the foliage unfurls in late spring.  Needs a sheltered site to protect the buds from late frosts.

Planning for the Autumn Part 2
Planning for the Autumn Part 2

Other plants to consider for this type of site:

Malus ‘Evereste’, Sorbus cashmiriana, Aster novi-belgii, Carex oshimensis ‘Evergold’, Geranium ‘Rozanne’, Pulmonaria ‘Sissinghurst White’, Monarda ‘Mahogany’, Helenium ‘Moerheim Beauty’

Sandy Soils

Easy to cultivate at any time of year, well aerated and quick to warm up in spring, sandy soils however have their disadvantages – generally very hungry and thirsty due to their structure being open and free draining, resulting in nutrients being quickly washed away.  The addition of a slow release fertiliser and a mulch of well-rotted manure, applied annually to a depth of 5-10cms, will aid water and nutrient retention.

Cercis canadensis ‘Forest Pansy’

The red bud can be a large deciduous shrub or small, often multi-stemmed tree, with deep red-purple heart-shaped foliage which turns vivid shades of orange and bronze in autumn.  The small pea-like bright pink flowers appear in clusters on bare stems in spring usually before the leaves appear, making a striking spectacle in the spring garden.

Planning for the Autumn Part 2
Planning for the Autumn Part 2

Ceratostigma willmottianum

An excellent compact shrub for brightening up borders in late summer, the Chinese plumbago produces intense blue flowers in terminal clusters which persist well into autumn, when the small leaves start to turn red, resulting in a vivid contrast of colours from one plant.  With a hardiness rating of 4, provide some protection if temperatures plummet below -10c.

Planning for the Autumn Part 2
Planning for the Autumn Part 2

Other plants to consider for this type of site:

Pinus Sylvestris ‘Aurea Group’, Betula ermanii, Robinia pseudoacacia ‘Frisia’, Perovskia ‘Blue Spire’, Phlomis fruticosa, Rosa ‘American Pillar’, Potentilla nepalensis ‘Miss Willmott’, Stipa gigantea

Chalk & Limestone Soils

If the soil over chalk or limestone is shallow, the main problem will be rapid drainage, which can result in these soils becoming dry and lacking in organic matter and nutrients, which are easily washed away by rainfall.

Generally light and easy to work at any time of year, a deep annual mulch will help restore natural nutrient levels and will assist in keeping roots cool.  Over time, a useful depth of soil can be achieved to grow a wider range of plants successfully.

Arbutus unedo

The evergreen strawberry tree has a multitude of attributes – glossy deep green foliage, red petioles, attractive mahogany coloured bark, which over time takes on silvery hues; bell shaped pink tinged cream flowers open during autumn, just as the previous season’s flowers are maturing to strawberry red fruits (unpalatable).  Available in tree or shrub form.  Arbutus unedo f. rubra has deeper pink flowers.

Planning for the Autumn Part 2
Planning for the Autumn Part 2

Prunus ‘Pink Perfection’

A British bred form of the popular Prunus ‘Kanzan’, ‘Pink Perfection’ is not as vigorous and therefore would be the perfect candidate for the smaller garden.  Young foliage opens bronze, later turning green and with some orange tints in autumn.  Double, pale pink flowers are produced in hanging clusters in classic ‘cherry blossom’ style in late spring.

Planning for the Autumn Part 2
Planning for the Autumn Part 2

Other plants to consider for this type of site:

Parrotia persica, Morus nigra, Ceanothus ‘Autumnal Blue’, Cotinus coggygria ‘Purpureus Group’, Osmanthus burkwoodii, Campsis radicans, Clematis ‘The President’, Rosa ‘Albertine’, Bergenia ciliata, Lamprocapnos spectabilis, Knautia macedonica, Pulsatilla vulgaris

Acid Soils

These soils are typically found in a woodland environment where their nutrients are replenished annually by the recycling of fallen leaves.  In a garden setting, if the soil is not excessively acid and just on the acid side of neutral, a wide range of plants are likely to thrive.  The addition of lime can help maintain such levels and a slow release fertiliser will be beneficial.  Smaller cultivars of Rhododendron and Azalea can be grown successfully in containers filled with an ericaceous growing medium.

Amelanchier lamarckii

The juneberry or snowy mespilus is a tree for all seasons, beginning in spring when the white petalled flowers open against a backdrop of young rich bronze foliage, which later turns green in late spring/summer and then brilliant red and gold in autumn.  Purple-black berries follow, which provide a winter bounty for the birds.  Available in shrub or tree form.  A. canadensis ‘Rainbow Pillar’ is a more upright form recommended where space is limited.

Planning for the Autumn Part 2
Planning for the Autumn Part 2

Enkianthus campanulatus

A deciduous bushy shrub with clusters of bright green leaves turning deep scarlet in autumn.  Hanging clusters of bell-shaped pink veined cream flowers are borne in late spring and early summer.  Preferring a moist soil, it will produce its best autumn colour if planted in sun.  Deserves to be more widely grown.

Planning for the Autumn Part 2
Planning for the Autumn Part 2

Other plants to consider for this type of site:

Cercis canadensis ‘Forest Pansy’ (detailed above), Acer japonicum ‘Aconitifolium’, Stewartia monadelpha, Camellia japonica, Embothrium coccineum, Fothergilla gardenia, Magnolia liliiflora ‘Nigra’, Skimmia japonica ‘Rubella’, Kalmia angustifolia, Pieris formosa

Planning for the Autumn Part 2