Managing Blackthorn Hedge
There is a butterfly called the brown hairstreak, which used to be widely distributed, but has declined to low levels nationally. The eggs of the brown hairstreak are laid on young growth of the blackthorn (sloe) tree. In former times hedges would be managed by being "laid" every few years. In modern times they get trimmed with a flail cutter on the back of a tractor. This removes pretty much all the brown hairstreak eggs.
Year by year we are chopping the tops off successive sections of our big blackthorn hedge to generate new growth and make a suitable habitat for the brown hairstreak. We don't have any yet but we live in hope!
Studies have shown that brown hairstreaks favour hedges where there are indentations creating sheltered bays in the blackthorn. We have been creating these as we go along. The hairstreaks also need ash trees in the hedge as assembly points for their courtship.
They prefer the "honey dew" exuded by aphids feeding on the ash trees over nectar obtained from flowers. There are already some ash trees in the hedge but more have been planted.