Coping with dry shade by Janine Pattison MSGD


We take a look at how to get the best from those problems areas

The Bournemouth area is famous for its tree-lined avenues and abundance of pine trees. In fact, Pinus sylvestris is so widespread in the area that it’s more commonly known as the ‘Bournemouth Pine’.

Having this amount of mature trees around is a great benefit to the area and they are -quite rightly- fiercely protected by the local authority. However, it does pose a real problem for residents with these large trees on their land: how to cope with the shade and dryness that results.

Dry shade is possibly one of the most difficult conditions to deal with in a garden. With too little moisture and low light levels, the essentials for plant life are in short supply. Plant growth will be slow and anything that does survive is going to have to be very tough! But, don’t despair; there are ways to make the most of the areas affected.

Begin by assessing the extent of the dry shade problem, then tackle it with a two-pronged plan:

  • improve the growing conditions
  • only use plants that thrive in these conditions

Look at the trees in your garden and see whether the shade they cast is too dense for life below. Check the soil beneath them: It may be damp on the surface but bone dry below – this is because the tree’s root system will use all of the soil’s moisture and food resources, and leave nothing for new plants.

It may be obvious where the dry, shady sites are in your garden, but you may need to explore the soil around to decide just how far the dryness and shade extends. Woodland areas can be both dry and shady, as the tree canopy prevents much of the rain penetrating the soil below. Structures such as houses, fences and walls will cast shade but will also create ‘rain shadows’; areas where rain simply doesn’t reach the ground.

Consider if it’s possible to increase light reaching the ground by removing the lower branches of the trees. This ‘crown lifting’ would occur naturally in the wild by animals browsing. Do take care to get written permission from the local authority if the tree is covered by a Tree Protection Order. Your local Council office will be able to advise you if permission is needed.

If your soil is sandy, (as most of the local area is), the problems of dry shade are made worse because moisture that does reach the ground drains away very quickly.

The first thing to address is the improvement in the growing conditions. The best way to improve the moisture retention of the soil is to add plenty of well-rotted organic matter, like farmyard manure, garden compost, composted bark or leafmould. This should be dug in and then raked over to create a well prepared area for your new plants. The organic matter will both ‘lock-in’ moisture and feed the new plants as it breaks down.

Like all jobs in the garden, you’re more likely to succeed if you grow plants that are adapted to their surroundings and in harmony with each other. If you get the balance right, the plants you choose will create their own environment, one in which they can thrive. Establishing a community of plants like those listed below also helps to retain soil moisture by reducing surface evaporation.

Bear in mind that in such testing conditions, even the toughest plants may not achieve their expected height and spread, so you may need to plant more closely than usually recommended. It’s also vital that new plantings are kept well-watered during the most vulnerable period before they develop a well-established root system. Consider installing a seep or porous hose irrigation system-the cost of doing so will be amply repaid in reduced plant losses and improved growth of your new plants.
Well rotted organic matter or shredded bark should also be applied as a mulch after planting, but it’s vital to do this when the soil is already damp. If applied to dry soil, it prevents rainfall reaching the soil beneath and makes the problem worse. Give the soil a thorough soaking before mulching. The mulch should be topped-up periodically as it breaks down into the soil.

Most people have some dry shade in their gardens and, fortunately, there are plants adapted to the conditions so, by choosing them, preparing the soil well and following some simple guidelines, it’s possible to transform the problem site into something beautiful to be enjoyed.

Janine Pattison is a registered member of the Society of Garden Designers and a qualified horticulturalist and she runs Janine Pattison Garden Design providing a professional garden design service across Dorset. She offers a free initial consultation and can be contacted on 01202 426143.

Action plan summary

  • Improve soil by adding compost or well rotted manure
  • Choose your new plants carefully
  • Water well after planting and before mulching
  • Mulch deeply after planting with shredded bark
  • Increase light levels if possible by removing lower branches of trees (remember that you need permission to do this if the tree is covered by a Tree Protection Order)
  • Reduce competition for water and nutrients by keeping shrubs under control
  • Consider adding a porous hose irrigation system

Top 10 plants for dry shade

  • Spotted laurel (Acuba japonica) -variegated leaves reflect the light
  • Lady’s Mantle (Alchemilla mollis) – attractive leaf and foamy flowers
  • Barberry spine (Berberis x stenophylla) – spiny, good to deter trespassers
  • Epimedium (Epimedium x versicolor) – evergreen with delicate yellow flowers
  • Ivy (Hedera hibernica) – evergreen ground cover
  • Holly (Ilex aquifolium) – native evergreen, berries in winter
  • Yellow Archangel (Lamium galeobdolon) – bright yellow flowers in spring
  • Mexican Barberry (Mahonia aquifolium) – evergreen, scented flowers
  • Skimmia (Skimmia japonica ‘Rubella’) – dark red buds opening to white flowers
  • Periwinkle (Vinca major) – pretty blue-flowering evergreen