Stuart | March 14, 2013 | 0 Comments
Just a few tips to help you choose plants within those tricky situations within your garden.
Heavy Clay Soil in Deep Shade
Clay soil is easily compressed when wet and water can be slow to drain away. This can make it cold and wet in winter and if this is compounded by being in a deeply shaded area, little light will be able to filter through. If the soil becomes water logged, there will be insufficient oxygen at the roots and the growth of the plant will be impeded, eventually leading to rot if the water logging persists. In long, dry periods, heavy clay soil can become hard and cracked making it difficult for roots to penetrate, particularly for young plants.
However, the water-retentive nature of heavy clay soil also means that nutrients are retained in the soil for longer.
Plants that cope well in these conditions will tend to have fleshy, rather than fibrous, roots. They are also more likely to have larger leaves to make the most of the available sunlight.
The following plants are suited to growing in these conditions:
Aucuba japonica
Viburnum davidii
Kerria japonica
Hosta sp.
Campanula lactiflora
Light Sandy Soil in Full Sun
The problem with sandy soil is that it has very little structure. Water drains away quickly as do nutrients. However, this also makes sandy soil quicker to warm up than a heavy clay soil. For these reasons plants that grow in these conditions have to adapt to suit the abiotic conditions. To reduce loss of water through leaves many plants have developed silvery foliage to reflect light. Alternatively they may have lots of narrow or deeply cut and spiny leaves to reduce the amount of water lost through transpiration. Plants with fibrous roots, such as grasses will do well as they have a larger surface area through which to absorb nutrients from the soil. Some bulbs do well in sandy soil as they do not like to sit in damp conditions. A bulbous plant is suited to growing in a soil that may be lacking in nutrients as the bulb is able to retain enough energy for the following growing season without having to rely on getting nutrients from the soil.
The following plants are suited to growing in these conditions:
Acanthus hirsutus
Eryngium
Allium christophii
Euphorbia nicaeensis
Cortaderia selloana
Linum narbonense
Permanently Damp Soil
Although there are many plants that thrive on permanently damp soil, the majority will start to suffer if their roots remain damp for prolonged periods. This is due to the plant being forced to respire anaerobically which does not produce as much energy as normal, aerobic respiration where there is an adequate supply of oxygen. In waterlogged conditions there will be insufficient oxygen available to the plant roots and those that have not adapted to this sort of environment will be unable to survive. Bog plants have evolved so that they can take in oxygen through other areas such as their stems so that they are not affected if their roots are permanently wet.
The following plants are suited to growing in these conditions:
Salix daphnoides
Viburnum opulus
Spiraea x vanhouttei
Gunnera manicata
Astilbe chinensis
Rodgersia pinnata
Rheum palmatum
Acidic Peaty Soil
An acidic soil is classed as pH 5.5. In this type of soil there can be a lack of magnesium and some plants may be more prone to conditions like club root. Ericaceous plants thrive in this environment, often found in woodland.
The following plants are suited to growing in these conditions:
Ericaceous Plants:
Rhododendron
Magnolia fraseri
Camellia japonica
Erica cinerea
Acer japonicum
Gentiana x macaulayi
Thalictrum diffusiflorum
In a very acidic soil (pH lower than 5.5) nutrients such as calcium and phosphorus are restricted. A lack of calcium causes nutrients to wash out of the soil and a lack of phosphorus affects root growth. In soil such as that found in peat bogs this severe lack of nutrients has caused plants to evolve in more extreme ways to find their nutrients elsewhere. Carnivorous (or insectivorous) plants attract, trap and digest creatures, often insects. As the insect decays, nutrients are released that can be absorbed by the plant.
Carniverous/Insectivorous Plants:
Dionaea muscipula – Venus Fly Trap
Drosera capensis – Sundew
Nepenthes glabrata – Pitcher plant
Coastal sites
Coastal sites suffer from exposure to harsh, salty winds causing plants to lose a lot of water. Coastal plants have adapted to reduce transpiration levels in a number of ways such as narrow or deeply cut leaves that reduced exposure, silvery foliage to reflect light and hairy leaves to retain moisture. As coastal sites are often sandy and free-draining as well, moisture retention is extremely important.
The following plants are suited to growing in these conditions:
Euphorbia nicaeensis – small blue-ish leaves
Senecio cineraria – silvery, hairy, deep cut leaves
Pennisetum alopecuroides – narrow, strap-like leaves, fibrous roots
Geranium sanguineum – deep cut leaves, low-growing plant
Escallonia – very small glossy leaves
Cytisus – very narrow leaves and small flowers
