During a heat wave, is it good to use an atomizer during daylight to spread water on the leaves of my Acer Palmatum?

Question

I couldn't resist, I offered myself an Acer Palmatum one week ago. And now we face one of the hottest heat wave nowadays in Europe.

I noticed some leaves are already dry, some of them are burnt. I water one day on two... and yesterday night I used an atomizer for the leaves.

But I wonder if I could also use the atomizer during the hot daylight. I fear that the droplets may act like magnifiers and burn the leaves all the more... I don't know. Is it a rationnal fear or is it completely unaccurate ? Will a little mist do any good to my Japanese Maple?

Answer 1

As to whether or not a fine mist spray will benefit your Japanese Maple, I can't say. It almost certainly won't do it any harm.

The matter of water scorching leaves, though, is just a myth. Far more damaging to your plant in times of drought than a little bit of water on the leaves is not watering when it shows signs of drought stress.

It's time to come clean - until I read The Informed Gardener by Linda Chalker-Scott recently, I would have avoided watering in the heat of the day, precisely because I would have been worried about scorching the leaves. However, the essay "The Myth of Hot-Weather Watering" dispels the myth convincingly. And of course, it makes perfect sense that wet leaves aren't susceptible to sunburn - every time we had a rain storm followed by bright sunlight, we'd see struggling plants and trees throughout the environment!

Answer 2

If you're growing Acer palmatum, there are two things you need to provide for it - dappled sunlight only between the hours of 11 and 3 during summer, and a sheltered spot out of wind. Hot sun will frazzle the leaves, and wind will have the same effect, and rather more quickly.

Obviously, in a pot, keeping it well watered is important - but well watered or not, if its exposed to winds, the leaves will frazzle regardless, particularly if it is a dissectum variety.

Answer 3

As others have said, I'm sure it won't hurt/sunburn the leaves, but I also doubt that it will do any good. Water evaporates so quickly in the heat of the day. I think you are better off focusing on keeping it well watered and letting it handle the transpiration itself. Do you have mulch in the pot? That would help keep it from drying out.

Answer 4

Only water high in minerals (especially sodium) can do some "burn" damage when watering in the heat. An exposed location is not good for maples. If you want to persist with it, try misting with a mixture of water and horticultural silica. It will help a bit with wind/sun burn.