Working outdoors, growing things, can be demanding. And this year has been a tough one, particularly for the trees.

Remember that long hot and dry spring. The driest in 50 years, according to the Met Office. While the warm conditions were initially favourable to plant growth, the lack of water started to cause stress. This was especially true for newly-planted trees. Thankfully we had some rain in the last few weeks of spring, a much-needed lifeline for the younger plants at Stone Lane Gardens, where most of the ground is sloping and free-draining.

Then we were hit with a second hot, dry period over the summer. With several heatwaves and almost no significant rainfall, this has been catastrophic for any plant without a deep and spreading root system.

Of course it's not all bad news. The sunny conditions and lack of spring frosts have been good for fruit production. Be it apples, blackberries, sloes, damsons, rose-hips or hawthorn, the gardens and hedgerows are burgeoning with fruit. My crab-apple jelly is tasting particularly good!

But if you observe the edges of roads and paths, you will see piles of dead leaves more reminiscent of autumn. This is a serious message from our trees – drought stress. Months of dry weather have put great stress on the vascular systems of our woody plants. And when this happens the trees respond by shutting down. In dry or windy weather plants lose a lot of water through their leaves, called transpiration. They can control the loss to some extent by varying the size of the holes (stomata) in their leaves, but when things become critical they drop the leaves.

This is a serious situation for a tree. It is still the growing season. It should be making energy for secondary growth and storing any excess to help it strengthen, survive the winter and have reserves for the next spring. By dropping the leaves, the tree is giving up most of its ability to photosynthesise and create energy. Remember those biology lessons; Carbon (from air) plus Hydrogen and Oxygen (from water) equals Carbohydrate (energy).

Of course if water is scarce it can't photosynthesise efficiently anyway, as without the water it can't extract hydrogen in order to complete the energy production process.

So the trees take a gamble, a trade-off. Slow down the water loss by dropping leaves, and hope you have enough stored energy to survive. With less energy. For a longer dormant period.

Now it gets critical. If the leaf loss is quite early in the summer, wetter conditions later may prompt a new growth spurt in the tree. And this is risky. Because those new leaves are from next year's dormant buds, used too early. The tree is using the leaves it was supposed to unfurl next spring.

Sometimes this is one stress too many, leading to the irrevocable damage or death of the tree. So the young trees in the new arboretum at Stone Lane Gardens are in a struggle for life. We look after them as best we can and hope for better days ahead!

Paul Bartlett works at Stone Lane Gardens near Chagford. The garden is open five days a week. More details can be found at stonelanegardens.com