Tree Planting in Cornwall - The less publisiced factors to consider

The Forestry Commission have a service available to all in helping to determine the correct species and more suitable areas in which to plant woodland, through their grants section and with advice taken from the FC bulletin 112.. However in areas like Cornwall, the rapid change in conditions; geology / climate and soils leads to complications as in a large estate, there will be a significant change, which must be considered, almost from field to field.

In 2007, CSL hired a soil science post grad student to carry out transects across the width of Cornwall to test the various soils found, concentrating on hedgerows and field margins. The edaphology would help us to determine what trees and hedgerow species are suitable along the various lengths of Cornish Hedge and surrounding land. A list of the species of trees / plants in the locations was also taken. On the back of this work we were able to propagate the species which suit for the hedgerows as well as an extended range which would also survive. Bearing in mind also the salt laden winds of Cornwall, (On a field 2km inland from the sea there is on average 80kg of salt dumped per hectare per year).

Luckily the public's interest and desire to plant more trees has not abated since the study, indeed partly as a result of the recession the interest has increased still further. But in order to guarantee tree planting success, we can now use the data collected to determine site specific tree planting. From native woodland through to orchard and ornamental planting. There is however still other factors to consider:

- Pest damage is on the increase, rapidly in Cornwall. Many more deer have been spotted in locations never before seen, Rabbits grow large down here, Squirrels are rampant and Hares are also on the increase, as such adequate protection is essential. For smaller trees, which are preferable in terms of their resilience to other factors, Tubex is often unsuitable because as soon as the tree attempts to push its leader above the lip, the harsh climate dissuades it. We have found spirals the best, but constant management to ensure they do not fly off is required. When Oliver Rackham gave the annual Cornwall Branch ITF lecture a few years back, he was asked what the single biggest threat to Woodlands and Trees in the UK was - his answer Grey Squirrels.

- Contaminated Soils are common here, many soils around the larger tin mining locations, contain levels of arsenic > 2000 times the EU preferred levels. The research into the uptake of heavy metals into fruiting trees is somewhat lacking in whether the resulting crop is suitable; it is best to assume it isn't. However there are of course many trees which will thrive on these soils and help to remediate the soil also. If in doubt plant an Alder.

- Micro Climate zones can sometimes be counter effective, the wet mild conditions allow for many species to flourish outside of their normal range. The soil conditions which go with this allow for a multitude of diseases to also flourish as well and the temperature variables periodically dip well below conditions a tree has become accustomed to, resulting in premature death.

- Non native invasive species have colonised huge tracts of Cornish Woodland and other land. Rhododendren is a major threat to trees, particularly recently when as a host to Phytophora kernoviae it has infected woodland trees in the county. This therefore means an additional cost in terms of maintenance requirements.

To this end, we have been working on a system, where when a client wishes to plant anything from a single specimen to establishing woodland or Orchard, we can by way of their postcode determine several factors prior to their choosing the suitable trees for their land. The trees chosen for the various locations studied are now available this year.

Shane Kneebone

Cornish Apple Trees