Article from Thame Out:
Matt Vaughan, director of 4 Seasons Tree Care describes a recent project to improve the health and vitality of two large old Cedar trees on a country estate in the Cotswolds.
Article from Thame Out: The two Cedar of Lebanon are over 200 years in age with huge stems and majestic spreading crowns typical of the species. They stand in a large expanse of well kept lawn and this, despite appearances, is where their problems begin. Both of the trees were in a slow but steady decline with sparse crowns and poor density of foliage. Cedar of Lebanon are able to live for at least 300 years in this climate so their decline pointed clearly to a problem with the soil that they were growing in. We took a series of soil tests for laboratory analysis to determine precisely the nutrient content and also the degree of compaction.
This confirmed our suspicions and informed the rescue plan for these valuable trees. Essentially, trees are designed to thrive in woodland or forest where their roots are in symbiosis with a richly diverse and complex soil ecology. Trees need mycorrhizal fungi, bacteria and a host of micro-organisms that will be present in healthy soil but may be lacking beneath the monoculture that is a well-kept lawn. The over-use of chemical lawn treatments and soil compaction only add further to the problems that trees like these can face. The only way to reverse the fortunes of these Cedar trees was to radically upgrade and improve the soil conditions using a
variety of specialist techniques that have evolved in the arboricultural world over recent years .
The first part of the project was for us to strip the grass around the trees to well beyond the edge of the canopy, where we expect fine, hair like feeder roots to be working. Once this is complete, we use a method known as vertical mulching. A network of bore holes to a minimum of 1 meter depth is drilled around the outer half of the root zone. Each hole is backfilled with a balanced blend of special additives.
We use a product called Biochar that we mix with strains of mycorrhizal fungi, beneficial bacteria, worm casts, trace minerals and a little organic mushroom compost. Biochar is an amazing product made by heating biomass, similar to the way charcoal is produced. It lasts in the soil for thousands of years helping drainage, aeration and
providing a niche environment for a host of beneficial fungi and bacteria. It also bonds with Nitrogen which can otherwise be readily lost from soil. So, when we use this product we are changing a soil in a permanent and sustainable way. We now have better drainage, better aeration and a kickstart to amending and developing a healthy soil ecology.
The next step in the process is to flocculate the upper soil level with a wonderful tool called an Air Spade. It uses a fine jet of compressed air to break up the soil to a depth of around 30 centimetres. The air stream breaks up the soil without causing damage to any roots that are present, giving a lovely fine tilth that any gardener would envy! Next, we add in more of that special blend of Biochar and soil improvers to further improve conditions over the whole of the root zone.
The final step is to top dress the whole area with a good layer of composted wood chip and water everything in really well. Essentially, we have created an environment that is closer to what is found in a natural woodland where trees can thrive in a symbiotic harmony with the soil – a more holistic approach to tree care without even starting a chainsaw ! If you have any tree related projects that you are considering – Four Seasons will be pleased to help.