Many Scottish gardeners have to contend with clay soils, especially those in flat valleys such as the Carse of Gowrie between Perth and Dundee. Clay soils are heavy, often to set and crack when too dry. Regular water-logging, compaction and lack of air around the roots can kill many plants, and the easiest way to deal with clay is to garden on it, rather than in it. Many plants can be far more successfully grown in raised beds, a minimum of 30cm high, containing lighter, free-draining topsoil or compost, held in by wood, rocks, cobbles and other materials. Or use containers.
Trees and Shrubs (incl. climbers)
Aucuba japonica Aesculus hippocastanum (chestnut) Berberis darwinii, B. stenophylla Chamaecyparis lawsoniana cvs Cornus alba (dogwood) Cotoneaster Cryptomeria Drimys winteri Hamamelis (witch hazel) Humulus lupulus aureus (golden hop) Metasequoia glyptostroboides (dawn redwood) Philadelphus Populus Pyracantha Quercus robur (oak) Ribes sanguineum (flowering currant) Roses (but dislike being waterlogged) Salix, including S. hastata, S. caprea, S. matsudana, S. chyrsocoma Sambucus racemosa Syringa vulgaris Taxodium distichum Viburnum opulus, V. bodnantense Vitis coignettiae Weigela floridaPerennials and bulbs
Ajuga reptans Aruncus dioicusAster nova anglicae, A. nova belgica
Astilbe Aruncus Astrantia Carex elata Digitalis Ferns, including Osmunda regalis, Polystichum setiferum Filipendula ulmaria Gunnera manicata Helenium Hemerocallis Hosta Houttuynia cordata ‘Chamaeleon' Inula hookeri Iris laevigata Lythrum salicaris Mimulus Monarda Persicaria affine Primula florindae, P. japonica Rodgersia Rudbeckia Solidago Trollius
Bulbs:
Camassia, Chionodoxa, Fritillaria meleagris, Galanthus nivalisPlants for Dry Shade
Low light levels and summer dryness make dry shade one of the tougher gardening problem areas. It only suits a fairly select number of plants, and getting plants established under trees can be difficult, especially trees such as beech and sycamore which are both greedy and cast a very dense shade. Physically digging between roots can be hard work, and it's often worth creating planting pockets with good compost to replace impoverished soil. Leylandii hedges are also bad news as they take so much moisture from the soil for up to 2m (6ft) either side, or more. The north side of a leylandii hedge is a particularly poor place to garden. Most plants with coloured and variegated foliage will tend towards green in deep shade. In general, planting is best done in autumn, once first rains have come. Eeverything should be regularly watered until roots are well established.
Shrubs
Aucuba japonica Cornus canadensis Euonymus fortunei Hedera hibernica Hypericum ‘Hidcote' Ilex aquifolium Lonicera pileata, L. nitida Mahonia Pachysandra terminalis Prunus lusitanica and P. laurocerasus Rhododendron decorum and R. yunnanense Ribes Rosa x alba ‘Alba Maxima' Rubus Ruscus aculeatus Sarcococca humilis Skimmia japonica Symphoricarpos Vinca Perennials Anemone x hybrida/japonica Astrantia Brunnera macrophylla Convallaria majalis Epimedium Digitalis (fox glove) Dryopteris filix-mas (Fern) Geranium macrorrhizum, G. phaeum and others. Helleborus argutifolius, H. foetidus Lamium Luzula (Grass) Maclaeya Pulmonaria Tiarella cordifolia Viola odorata Bulbs: Eranthus (aconite) Cyclamen, Galanthus (snowdrop) Hyacinthoides (bluebell)
Plants for moist shade
Provided the soil is not waterlogged, nor the shade too dense, moist shade can support a wide range of plants. The edges of the crowns of trees and large shrubs are ideal, whereas right underneath the middle of a dense tree such beech will be too dark and too dry for almost all plants. The north side of walls often provide sites with moist shade.
Shrubs
Aucuba Bamboo Berberis Buxus sempervirens Callicarpa Desfontainea Gaultheria Hydrangea Ilex Mahonia Osmanthus Prunus laurocerasus and P. lusitanica Rhododendron (and Azalea) dappled or part day shade only.Perennials and Bulbs
Alchemilla mollis Arum italicum Astrantia Bergenia Brunnera Dicentra Digitalis Dodecatheon Ferns Gunnera Heuchera Hosta Luzula sylvatica Tiarella Tricyrtis TrilliumBulbs:
Camassia, Cardiocrinum, Galanthus, Eranthis, Narcissus (species)