Lime-tolerant plants Take advantage of chalky soil and discover how you can create a diverse and inspirational garden using lime-tolerant plants.

In this article

Lime-rich soils

Which plants?

Soil preparation

Lime-rich soils are also known as alkaline or chalky soils, and have long been maligned by gardeners for their severe dryness, poor nutrient levels and being full of stones. However, by choosing the right plants and following a few soil preparation tips you can create a stunning garden on even the chalkiest of soils.

Many of the UK's most beautiful landscapes are based on thick chalk bedrock that covers much of southern, coastal England.The chalk that gives the Cliffs of Dover their brilliant white colour is what causes high alkaline levels in the surrounding soil - lumps of chalk are often visible when digging in limey soil. Such soils are dominant in the South East, while areas less likely to have lime-rich soils are Cornwall, Wales, north-west England and most of Scotland.

In alkaline soils, many plants have difficulty absorbing nutrients such as iron and magnesium, which can result in poor growth and yellowing leaves. A soil testing kit will instantly indicate whether your soil is acidic or alkaline. Water quality and soil type are closely linked, therefore, if you live in a hard water area, with high levels of lime deposits, it's likely your soil will be more alkaline.

Despite being very poor and dry, chalky soils often support stunning ecosystems, for example, the wildflower meadows of the South Downs and the rugged flora of the Mediterranean. The key to creating a beautiful garden on chalky soil is to recreate aspects of these natural ecosystems in your own garden, by choosing species that are naturally adapted to these environments.

Plants that thrive in chalky conditions include beautiful native wildflowers such as poppies, cornflowers and chamomile, with many of these plants performing better in poor, chalky soil than rich garden beds. Likewise, plants from the chalky American prairies, such as echinacea, lisianthus and rudbeckia, prefer thin, lime-rich conditions.

Alkaline soils tend to be well drained and warm up quickly in the spring

From warmer climes, aromatic and drought-tolerant Mediterranean species such as lavender, rosemary, bay and fennel, thrive on these soils, with the bonus of not needing constant watering. Also, as alkaline soils tend to be well drained and warm up quickly in the spring, gardeners on this type of earth often succeed with half-hardy and tender perennials that would not survive in colder, wetter soils.

Avoid plants that prefer moist woodlands and heaths, where the soil is naturally more acidic. The most notorious of these lime-hating plants are rhododendrons, camellias, azaleas and heathers. If you have alkaline soil, these should be grown in tubs or pots filled with ericaceous compost.

The quality of limey soils can be greatly improved by adding large quantities of compost and well-rotted manure. This provides nutrients and organic matter and, as a guide, should be added at the rate of one wheel-barrow load of organic material for every 2.5sq m (8sq ft) and dug in thoroughly. After planting, a thick layer of mulch applied around plants can help conserve water loss, and in time breaks down to further improve the soil structure.