It’s hotting up… the skies are blue with hardly a wisp of cloud to be seen, and the forecasters are telling us it’s going to be a heatwave. While the natural reaction to this may be to don your shorts, scoop buckets, spades and the kids into the car for a 10-hour drive to the coast to binge on fish ’n’ chips and 99s, spare a thought for the trees in your garden. The warm British summer may often be fleeting, but the heat and the drought it causes can be a killer if you don’t look after your garden’s shade-givers.
When the baking sun beats down on us, evaporation rates go up, and just like you and I, trees can suffer from dehydration. As the ground becomes dry and cracked, older trees with deeper roots may typically be more resilient to the dangers of dehydration as the further down the cooler and damper the soil should be. But this is not always the case, as root depth and soil type may all influence the moisture your trees are getting.
And when a tree does not get enough water its limbs become drier and more brittle, sometimes leading to what’s called ‘summer branch drop’. This is when, without warning, branches simply drop off as a tree prioritises getting moisture to some areas and sacrifices others for its continued survival.
In interviews with the press about this in the past, The Arboricultural Association stated: “The indications are that it’s to do with water stresses within very large, often overextended or elongated limbs.” And that certain species of tree, such as beeches, oaks and horse chestnuts, are more susceptible.
Trees in urban areas have the added issue of ‘urban heat islands’ to contend with. This is when towns and cities are hotter than the surrounding countryside due to many factors, including pollution, reflective surfaces, and a lack of trees (which naturally cool the land). With less shade and more heat in urban environments, trees are at a greater risk of dehydration.
So, what can be done in your garden to keep your trees healthy and hydrated?
- Water your trees
Of course, it’s obvious, but if you believe your trees are lacking water, then water them. Watch out for dry and cracked soil, as this will be a sure sign that the moisture has been sucked out of the soil and it’s heating up far more than it usually would around your trees. Early morning or late evening are the best times to water trees as they are out of the heat of the day, but be careful not to overwater them. Remember, you’re just looking to rebalance the ground moisture, prioritising smaller trees that could suffer more from the heat.
- Mulch around your trees
A good organic mulch, spread around the base of your trees, to a thickness of 2–4 inches, will offer them some respite. Mulch serves to regulate soil temperature as a protective layer over the surface, and it will help the soil to retain moisture so that thirsty tree roots can get to it before it evaporates. Just be sure not to pile your mulch up against the trunk of your trees as this can encourage the growth of fungi and offer a warm place for insects to thrive.
- Reduce moisture competition
Your trees are competing for moisture with every other living thing in your garden with roots – plants, flowers, bushes, and even grass. So, another thing you can do is to reduce that competition by relocating plants that you find under trees, weeding to remove what shouldn’t be there in the first place, and cutting back grass from the base of your trees to form a ring of earth (to cover in mulch of course) so your tree roots are no longer fighting for dominance over any water in the soil.
- Ask a professional
Dry earth and dehydrated trees could lead to weaknesses, which may result in trees being more susceptible to limb breakage, disease, infestation and even uprooting in the next storm. Large trees with ‘overextended or elongated limbs’ should be cut back or pruned, young trees and saplings that are the most susceptible to sweltering heat issues will require more watering and shade, and in extreme circumstances, relocating. And you could simply ask your friendly neighbourhood arborist to do a tree survey and a report to offer their advice on all that needs to be done right now, while setting in place a plan for the best health of your trees all year round.
To find out more about how your trees can be protected from the sweltering heat of summer, call us on 0208 292 8992. We’re always happy to pop round or to help with a little advice.