Down to earth
Our gardens will only ever be as good as the soil that supports them.
Before you set out to create a new garden, find out what soil type you have. Is it acid or alkaline, clay or sand? Take the time to prepare the proper soil environment before planting. Good soil preparation is the most important thing you can do for your flowers.
Get a testing kit to reveal your soil's ph. Acidic soils (ph 0-7) tend to be low in phosphorous; alkaline soils (ph 7-14) may lack iron and manganese. Most plants will grow in either soil, but some are suited only to a particular ph level. Rhododendrons and camellias like acid soil.
CLAY OR SAND?
Roll a handful of damp soil between your fingers. If it forms a solid sausage, you have clay soil. If it feels gritty and falls apart, it is mostly sand. You can also put a little soil in a jar of water and shake it. If the water is clean on top after an hour, you have sandy soil.
Add grit or coarse sand to clay soil to improve drainage. Don't add fine sand; it can make clay soils worse because it blocks soil pores. Add lime or gypsum. Add organic matter; it opens up a soil's structure and improves drainage. Mulch with compost in late spring.
PLANTS FOR SAND AND CLAY
Sandy soils drain so well that plants never suffer from cold, wet feet. The downside is in summer, they can't hold on to moisture, so only very drought-tolerant plants survive. They're often poor in nutrients, but they warm up quickly in spring. Feed sandy soils with slow-release fertilisers such as organic blood and bone rather than highly soluble store-bought varieties, or potash and ammonium nitrate, which will quickly be washed away and may go on to pollute our natural watercourses.
Deep-rooted plants that can probe and quest for moisture are going to do better in sandy soil than shallow, fibrous-rooted subjects. Plants from ancient soils and arid climatic zones, such as South African protea or Australian grevillea, will love the poor conditions and arid outlook, not to mention other Mediterranean climate classics such as Californian lilac (ceanothus), lavender and cistus. Any shrub with a grey leaf, such as Russian sage (perovskia) or artemisia, will thrive in sandy soil too.
Most clays in this country are slightly acidic and contain a good level of nutrients. Tough traditional herbaceous plants such as aster, astrantia, canna, clivia, geranium, paeony, phlox, hemerocallis (daylily) and lupin will do well. In heavy soil they won't spread so fast and will need dividing less often. Heavy soils also tend to harbour slugs – that's why they are not great for growing fussy and delicate plants such as delphinium and echinacea. The classic shrub for heavy ground is the rose, but hydrangea, spirea, philadelphus, weigela and viburnum will do well too. Good bulbs for clay include most narcissus, schizostylis, zephyranthes and slender reed-like Onixotis triquetra, with its startling winter flowers.
Good organic garden soil is filled with air that plant roots need, and it has plenty of minerals essential for vigorous growth.