Dead wood for wildlife
6 April 2009
An important, but often overlooked, element of the garden is the presence of dead and decaying wood.
Standing and fallen decaying wood and old plants are very important for wildlife. Even just one or two bushes, if kept beyond their natural life, are of great value to insects, fungi, mosses and lichens.
Birds feed on insects that make their home in old wood. In large gardens, a decaying tree with a snagged bough or a small cavity might provide a nest site for a bird or bat.
Dead branches also make excellent song and display perches for birds.
Keep decaying wood on trees and shrubs
- Leave dead trees and shrubs standing (as long as they are not in a dangerous place) to decompose naturally.
- Unwanted plants or trees can be killed by ring-barking and left to provide a source of decaying wood. Make two thick cuts, about 20 cm apart, around the trunk and deep enough to cut through the bark and into the wood. The bark between the two cuts should also be stripped from the tree.
- Ring -barking individual shrub stems also produces standing decaying wood without killing the whole plant.
- Ring-barked plants will sprout from below any wounds and may need continual cutting of growth to completely kill the plant.
- Leave old stumps to decay naturally and only remove them if necessary.
Create a woodpile
Take the worry out of disposing of those bulky cuttings and create a home for wildlife. Woodpiles are a valuable habitat for mosses, lichens and fungi, as well as many insects.
- Leave woody cuttings from trees, shrubs and herbaceous plants in piles within a shrub bed.
- It is best to not cut the wood into small pieces. Leave it in direct contact with the ground, in dappled shade and in compact piles to maintain humidity. Larger diameter pieces are of most value, but even small twigs and branches should not be discounted, and neither should the cut stems of herbaceous plants.
- Full sun will dry and heat the wood and it will support little life. Dense shade is good for fungi, but may be too cold for most insects.
- Add to your decaying wood, using wood from friends and neighbours. A local tree surgeon may also be able to supply you with some logs. Avoid taking logs from woods and hedges as you will be removing the resource from its natural environment, along with any associated flora or fauna.
- Logs at least 100mm thick (4 ins) with the bark still attached provide the best wood. Hard wood trees such as ash, oak and beech are particularly good. Birch logs can look particularly attractive. Be careful of freshly cut willow and poplar logs, as these can easily re-sprout if left lying on the ground.
- Allowing a climber to ramble over woodpiles, logs and stumps can cover them and help retain moisture. However, the shade may make it too cold for some insects.
- Alternatively, use an old 15 litre (3 gallon) bucket. Drill some drainage holes in the bottom and cut lots of holes (30mm or 1.25 ins) in the side of the bucket at 50mm (2ins) spacing. Put some large stones in the bottom and then quarter fill the bucket with garden soil and top with course hardwood chips. Completely bury the bucket in a discrete corner of the garden.
- Lay a stack of logs laid on their side. To prevent them rolling, drive a stake into the ground either side of the pile.
- You can create standing dead wood by partially burying logs vertically in the ground to an approximate depth of 450 to 500mm (18 to 20 ins). Use logs of different diameters and length and bury them side-by-side to form a pyramid. If space is a limitation, a single log either buried in the soil or on top is still of value.
Providing dead wood on balconies and terraces
- Fill an old bucket with a mix of wood chippings and soil, with a series of holes made in the side. On a balcony, it can stand among tubs and planters. This can be filled with a mix of soil and hardwood chippings.
- Lay logs on their sides to form a square or rectangle, which can be filled with a mix of soil and hardwood chips.
- You can also lay logs among planters, or even place or part bury them as a feature in a tub.