Plants for chalky soil with pink and red flowers

Plenty of plants, of a variety of shapes, sizes and colours, thrive in the higher pH of chalky soil, so it’s perfectly possible to create a full and attractive border even in these sometimes challenging conditions

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Many plants thrive in chalky soils
Many plants thrive in chalky soils

Quick facts

  • Chalky or limey soils can benefit from the addition of plenty of organic matter to improve water retention
  • Many plants are not pH-sensitive
  • Chalky soils tend to drain quickly, even in wet weather, so can be good for Mediterranean plants

The planting plan

James Lawrence, RHS Principal Horticultural Advisor, has designed this simple, attractive, and most importantly, sustainable border design for you to try at home with plants that are easy to grow, widely available and look good together.

This pink and red-themed planting design provides a range of plants that, once established, will thrive in alkaline, chalky or limey soil to provide a variety of interest throughout the year. A simple planting plan helps to create depth, interest and good coverage in a border.

Pink and red plants for chalky soil

Choosing plants for chalky soil

These plants have been selected because their preferred growing condition is alkaline soil. By using plants that are naturally adapted to these conditions, we can enjoy healthier plants and lower inputs compared with trying to grow plants that are less well suited.

The Geum and Heuchera provide some groundcover and will help prevent erosion of bare soil. The groundcover can also help to suppress weed growth and reduce evaporative moisture loss from the soil surface.

Additional organic mulching, preferably with homemade compost, can further improve soil moisture retention and weed suppression. Mulches should be spread when the soil is already moist, to help trap some of that moisture before it dries out in summer.
 

Aucuba japonica ‘Crotonifolia’ 
Deutzia x hybrida ‘Mont Rose’ 
Heuchera ‘Green Spice’ 
Geum ‘Mrs J. Bradshaw’ 
Anemone hupehensis ‘Praecox’
Syringa pubescens subsp. microphyllus ‘Superba’ 
1 - Aucuba japonica ‘Crotonifolia’ is an evergreen shrub that creates structure through all seasons with large, leathery green leaves heavily spotted and blotched with deep yellow. The small flowers are dark purple and on this female variety are followed by bright red berries.

2 - Deutzia x hybrida ‘Mont Rose’ is a medium-sized deciduous shrub with clusters of pale purple-pink star-shaped flowers in early summer.

3 - Heuchera ‘Green Spice’ is a perennial with semi-evergreen mounds of leaves that are marbled silver-green, with burgundy veins edged with green. Pale pink flowers are held high in late spring.

4 - Geum ‘Mrs J. Bradshaw’ is a herbaceous perennial producing bright orange-red flowers with golden yellow stamens in the centre in late spring-early summer, held high above ground-level dark green foliage.

5 - Anemone hupehensis ‘Praecox’ is an upright herbaceous perennial with three-part leaves and bowl-shaped, pink-purple flowers in late summer and autumn.

6 - Syringa pubescens subsp. microphylla ‘Superba’ is a deciduous shrub with dark green leaves and upright sprays of fragrant rosy pink flowers in late spring to early summer.

About alkaline, chalky soils

Alkaline soil is common in areas of the country with a lot of chalk or limestone. By choosing plants that are well-suited to chalky or limey soils, you can keep your border looking good and growing well, because plants that are planted in the right place tend to be stronger and more naturally resistant to pests and disease. Once the plants are established, this will also reduce the need for extra water and fertilisers that less well-adapted plants would need.
 

The challenge of growing on chalky soils

Chalky soils can be very fast-draining, so have the same issues as sandy soils in that respect. However, the most important thing to bear in mind is that the high pH of chalky or limey soils can cause some minerals to be ‘locked up’ in the soil, leaving the plant unable to take them up and struggling to grow. However, if you choose plants that have adapted to naturally thrive in those conditions, they will grow much better. 
 

Why choose a sustainable planting combination

Using the ethos of ‘right plant, right place’ to create a sustainable planting combination is great for the environment. It helps to avoid waste and the use of products and practices needed to try and help ailing plants, such as applying fertiliser. It also creates robust, long-lived planting that benefits soil health and garden biodiversity.

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