Gum control

One particular route I like to walk with the dog takes me through a wooded path between farm fields that's hedged on both sides by copsed hazel and the occasional wild cherry tree. Cherries are a very distinctive tree as they have horizontal lines on their bark (lenticels) and oval leaves with sawtoothed edges. And, of course, they produce cherries around this time of year. The fruit are small and very sour but the birds love them and distribute the seeds in their droppings.   

However, today I came across one old cherry that is having a bit of a rough time. It was oozing a thick resin that hardened in the air. I managed to catch a photo on my phone of a drip frozen in time.

You expect to see resin weeping from evergreen trees like pine or spruce - it's what ensnares and entombs insects and then, over millions of years, hardens into amber (one of a very few gemstones made by living organisms - others include pearls, coral and jet, which is fossilised wood). But there are very few deciduous trees that produce resin and, when they do, it's often a sign of distress or disease.

This is called gummosis and the most common cause is an opportunistic fungus called Leucostoma that infects easy targets like weakened trees or 'open wounds'. Sure enough, this big old cherry has been cut back in the last six months to keep the path clear. Leucostoma can also affect other fruit trees like peach, apricot, plum and apple.

The resinous gum works rather like a scab in that it seals the wound. And I'm pleased to report that this tree is not producing gallons of the stuff and the canopy looks fairly healthy. So I'm pretty sure the tree hasn't developed a leucostomic canker and it will probably recover. 

I hope so. It's an awful thing to see a tree die. 

Insert 'losing your cherry' joke here.