Weather and the Gardener
March brings the first real signs of spring. Spring in the garden comes earliest in the far south-west and latest in the nort-east, with the west coastal regions always being ahead of the east. Another important factor is the height of the garden above sea level, for spring is about three days later for every 30m (100ft) increase in height, and a southern facing slope always earlier than one which is facing north.
Remember also that spring flowers depend on "March winds and April showers", the purpose of the winds being to help dry out the top layers of the seed-bed so that the gardener can create a good tilth.
Trees and Shrubs
Among those in flower in the month of March will be some acer (maples), magnolias, prunus (ornamental cherries), rhododendrons and azaleas, salix (willows), sorbus (mountain ash), camellias, chaenomeles (Japanese quince), Corylopsis pauciflora, Daphne mezereum, various ericas (heaths and heathers), forsythia, hamamelis (witch hazel), mahonia, osmanthus and Viburnum tinus.
Pruning
Remove old wood from plants that have flowered during the winter, such as Chimonanthus praecox (winter sweet), Lonicera fragrantisima (shrubby honeysuckle), viburnums, Jasminum nudiflorum (winter jasmine). Also remove some growths from winter coloured stemmed plants, such as cornus (dogwoods) and salix (willow), to encourage new, brightly coloured shoots. Remove dead flower heads of winter flowering ericas (heaths and heathers).
Cut out shoots, to within about 5cm (2in) of old wood, from plants that flower in summer on new growths, such as Buddleia davidii.
Pruning of hybrid tea roses may be hard, medium or light depending on the growth of the bush and the purpose for which it is required. In general, however, prune all main growths to within four or five buds from the base, and side shoots to two or three buds, and remove dead or diseased wood.
With floribundas, cut back new shoots to about one third their length, older stems to about half their length, and old wood with new growth to two or three buds from the base.
Planting
If possible, complete the planting of all new hardy trees, shrubs and climbers. Evergreens and plants such as lavandula (lavender), rosmarinus (rosemary), hydrangea, cistus (rock rose) and santolina which are not fully hardy until established, are also planted at the end of March or the beginning of April.
Soil Cultivation
Hoe the soil shallowly around trees, shrubs and climbers, taking care not to damage any roots near the surface, and apply a 5cm (2in) layer of mulching material, such as well rotted compost, peat, shredded bark or similar material, with the addition of a general purpose slow-acting fertilizer. Use a peat mulch for acid loving plants such as rhododendrons, azaleas and ericas.
Flowers
Take 8-10cm (3-4in) long basal cuttings of lupins, delphiniums and border chyrsanthemums, Cut them away from the clump, with a sharp knife, and remove the lower leaves to retain a health growing point. Insert them to half their depth 10cm (4in) apart round the edge of a 13cm (5in) pot of equal parts peat and sharp sand mix. Water in and root in a warm lightly shade dplace, such as a heated frame.
Mulch round plants if the weather warms up, with well decomposed manure or old garden compost. Spread a 5cm (2in) thick layer over the soil to insulate the roots from summer heat and provide a downward flow of nutrients to the roots.
Alpines
Divide congested clumps of thyme, camanula, achilla and other summer flowering plants. Split crowns into nicely rooted pieces 5-8cm (2-3in) across and replant them 15cm (6in) apart in a gritty rich soil consisting of equal parts loam, peat and stone chippings or sharp sand.
Spread slug bait round newly emerging hostas and other fleshy stemmed plants that slugs can ruin by nibbling holes in the leaves.
Bulbs
Plant summer-flowering bulbs. Gladioli, specially the grandiflora hybrids with their 90cm (3ft) stems, can be set 8cm (3in) deep and 15cm (6in) apart. The smaller butterfly and primulinus hybrids are best planted only 5cm (2in) deep.
Feed naturalized bulbs carpeting rough-grass areas by scattering a balanced fertilizer high in potash, to stimulate strong growth for the coming year.
Remove faded blooms of earlier flowered bulbs to stop seed formation depriving plants of energy needed for making new growth.