Climbing plants for alkaline soil
Alkaline or “sweet” soils are those with a pH of more than 7. Some great climbing plants for alkaline soils include clematis, hydrangea and lonicera. Clematis is one of the most popular climbing plants, well-known for producing masses of distinctive flowers available in a broad palette of colours. They come in a variety of different shapes and sizes from vast, vigorous varieties to compact climbers, with a mix of evergreen and deciduous types too. Clematis are perfect for covering walls, arches, pergolas, fences and unsightly tree stumps. They prefer to have their heads in the sun and their roots in the shade, so use other plants to provide the necessary shade or cover the ground with stones or flat pebbles. Climbing hydrangeas are a valuable addition to any garden with beautiful, fragrant clusters of white, airy flowers above large deep green, serrated, heart-shaped leaves. They make an eye-catching choice for growing up walls, trees and pergolas, as well as being a brilliant ground cover plant for securing soil on slopes and inclines. Most varieties are relatively slower growing than other climbers, so whilst they can grow very large over time, they're relatively easy to keep in check if you prefer to restrict them to a smaller space.
Honeysuckle, also known as lonicera, is the classic twining climber of the cottage garden which will also succeed in an alkaline soil. Honeysuckle have highly ornamental, large cartwheel-shaped flower heads consisting of wonderful, tubular individual flowers each exuding a sweet fragrance. The blooms are produced in hues of white, yellows, reds, oranges, pinks and purples with long stamens, contrasting beautifully with the lush foliage. Most varieties are deciduous with rich bronze new growth bringing additional colour and interest as they come into leaf in the spring. Alkaline soils tend to be high in chalk content. Chalky soils tend to be free draining and less fertile than neutral soils. The pH of alkaline soils can be reduced, bringing it closer to neutral, by applying sulphur or ammonium. However, we generally recommend choosing types of plants that are well suited to the alkalinity of your soil, rather than trying to change it. Any artificial change to acidity will only be temporary and will need to be repeated over time. If the depth of top soil in your garden is particularly shallow before hitting solid chalk, additional top soil should be added on top of your ground to make planting viable.