Trees on green can still recover
PUBLISHED: 17:20 03 November 2010 | UPDATED: 11:30 05 November 2010
As I have some experience of growing copses of establishing orchards, I decided to follow up on the article from Cllr Roy Coombs in the Herald of October 20.
The only dead tree is near a garden fence at the north end of the park and its leaves certainly seem pretty dead. A small rectangle of bark has been removed from the trunk about two feet above the ground, and this shows that the wood seems to have been damaged; however, only close examination would show whether this was the result of fungal attack.
Further examination of this and other young trees in the area show marks that are consistent with the effect of tree spirals and tubes that have been left on for too long. I hasten to add that I was not here in 2000 to see how these trees were planted, and can only assume that spirals were used due to the visible marks left on the trunks.
Typically, whips will have stem diameters of 0.5 – 1cm and, for the first couple of years, there is a reasonable air gap.
However, by five to 10 years, the situation is very different. The expanding stem in the spirals, spreads the plastic out which then tends to stick to the surface of the bark.
The plastic holds the humidity against the stem and the young bark cannot breathe through its lenticels. The result is that the bark turns black and various rots attack the plant. Once a disease organism is in the vascular system, it quickly reaches the rest of the plant. By the look of the young trunks, some specimens have had narrow escapes, but provided that it has not been infected by a pathogen, the bark heals within a season.
I doubt that further problems, other than over-crowding and planting too close to the path, will be seen in this pleasant park as it is sited on a very nice free draining loam soil.
Heathfield Estate, Honiton.