How do you protect your trees against summer heatwaves?

[leatherback]

Hi All,

In another thread there was a suggestion I should do a video on summer protection of trees. I was wondering: What tricks/tips do you have to deal with hot/dry weather in summer.
(And do you have pictures or would you be willing to share a few secs of video showing setups you have in place?).
Over the weekend I might compile a video on this topic.

J.

 

[Gabler]

Automatic sprinklers. Evaporative cooling is generally enough, but around here it doesn’t get much higher than 100 degrees on the hottest days (that’s something like 38 degrees in Celsius). We’re not in Arizona or anything.

I keep some of my trees in direct sunlight all day, and the extra water is still plenty to cool them off.

 

[BobbyLane]

Ive never had any issues in heatwaves, I could go a day without watering no problem. and water once a day if i wanted to. I usually water twice though. my mix is probably more moisture retentive than most and organic heavy. plus I often top dress with sphagnum moss.

 

[MaciekA]

I have some fairly water-hungry tree species like populus trichocarpa and acer macrophyllum which may not be as heat-durable as any of my conifers, but do seem to be evolved for Oregon's hot dry summers and which I place in the sunny zone with my conifers. During heat waves: Strong ambient light OK, dry breeze OK, ambient heat OK, but combining all of those things with bright direct sun leads to overly-rapid drying and leaf scorch for me.

In past years, during extreme heat, I've either moved those trees into alternate spaces or put up a very large overhead shade (my only option at the time). This helped in last year's big waves where we either had humidity below 20% or temperatures as high as 47C. At the same time, the large overhead shade was awkward and also cast a lot of shade on my pines/conifers, which don't need the shade.

So this year, I started to experiment with the idea of applying "tactical shade" to single broadleaf trees that happen to be growing in my hot-bright conifer area. I've found that I don't need to shade the entire canopy, I can get away with shading 80 to 90% of the canopy without running out of water too fast. For this, I have been using round metal tomato cages turned upside down (wide rings placed on ground) and then attaching flat rectangular shades (w/ crosshatched plastic) to those cages, with the shades positioned and angled so that they block peak sun. This helps those trees make the journey from 10:45AM to about 4:30PM (when the sun finally dips behind some shade) without experiencing a rapid dryout.

These tactical shades look very makeshift (and so I don't want to post pics), but the "canopy 80-90% shaded at peak" idea works great, and I only need it on days that are more roasty or reach a crossover point (i.e. temp in Celcius greater than humidity percentage, eg: "33 > 25" for 33C and 25%). Maybe I can build a more attractive design for next year that looks more legit.

This is not a solution I'd use on trees that are in bonsai pots or trees that sit up on a table. These are trees in development in anderson flats / colanders / etc which don't crumple under extreme heat as fast.

 

[Dav4]

I’ll generally switch from my typical hazy IPA or stout to a lager, and maybe even move to a light beer like corona

That, and I water more.

 

[Kadebe]

- 50 % shade cloth
- wet towels on pots to reduce pot temp
- watering... trying to let the trees not go in summer dormancy

 

[Wires_Guy_wires]

I've given black pots a layer of white paint, or wrapped white paper around them.
And I hate to admit it because I like being spartan to my treees, but I have placed one tree on the ground :-(

 

[Paradox]

My maples and azaleas are on a bench that gets morning sun and afternoon shade so that when the heat really ramps up, they are already in the shade during the hottest part of the day.

I tend to water twice when it gets really hot. The trees get their usual morning watering and Ill water again around dinner time if they look like they need it.

I really dont change anything for the pines and junipers. They get their once a day watering and thats it since they dont mind drying out a bit between waterings.

 

[Wulfskaar]

In southern CA, our fall heatwaves also come with extremely hot, dry wind.

The last two year have proven that young trees don't like this.

I have set up a small greenhouse that I'm hoping will lock in some moisture and reduce the wind effects. We'll see how that works out soon.

 

[rustygarden]

I’ll generally switch from my typical hazy IPA or stout to a lager, and maybe even move to a light beer like corona

That, and I water more.

Love it .

 

[michaelj]

In southern CA, our fall heatwaves also come with extremely hot, dry wind.

The last two year have proven that young trees don't like this.

I have set up a small greenhouse that I'm hoping will lock in some moisture and reduce the wind effects. We'll see how that works out soon.

Keep an eye on the temps in that greenhouse. If it gets direct sun, it can get bonsaicidally hot in there. I lost some trees a few years ago from a single day of not watching the heat in my little plastic wrapped greenhouse.

 

[Bonsai Nut]

I’ll generally switch from my typical hazy IPA or stout to a lager, and maybe even move to a light beer like corona

That, and I water more.

Corona IS a lager... just sayin' (beer geek)

 

[Wulfskaar]

Keep an eye on the temps in that greenhouse. If it gets direct sun, it can get bonsaicidally hot in there. I lost some trees a few years ago from a single day of not watching the heat in my little plastic wrapped greenhouse.

Good to know!!! It's currently getting only late morning sun, but I plan to move it under a large oak tree into mostly shade.

Is it dappled shade or dappled sun?

 

[BeepBeepBonsaiSheep]

When it hits 90 consistently, I’ll throw on the shade for the bench (first yr with it)

When it hits 100, I’ll water in the late morning or afternoon and do a mist/shower early evening

At 108+, I’ll start to water twice and more misting/ showers

Nearing 115 middle of summer, I’ll prob do 2 waterings and full showers multiple times a day… prob every 2hrs

I’ve started to do the misting/ showers this summer. Seems like everything likes that

 

[Dav4]

Corona IS a lager... just sayin' (beer geek)

I should have just written "Corona light" -emphasis on "light". It's really the only light beer I'll drink.

 

[Katie0317]

Overhead light shade in Florida...Put the maple in an orchid house (mostly shade).

 

[Eckhoffw]

Keep an eye on the temps in that greenhouse. If it gets direct sun, it can get bonsaicidally hot in there. I lost some trees a few years ago from a single day of not watching the heat in my little plastic wrapped greenhouse.

Yes. Here my green house is averaging 25 degrees F hotter on sunny days.
all 4 vents open, but I need to get a fan.
also., the entire roof has a 40% shade cloth.

 

[TN_Jim]

Ive never had any issues in heatwaves, I could go a day without watering no problem. and water once a day if i wanted to. I usually water twice though. my mix is probably more moisture retentive than most and organic heavy. plus I often top dress with sphagnum moss.

yep same -tho my organic is only sifted pine bark, spaghetti topped if needed, and hardly never water twice
7a
90+s
rain yesterday and through the night, didn’t water any today
6 hrs ~+ sunlight, maples next to conifers
baskets tend to dry faster than most pots seems..

 

[casun]

If the high temperature is expected to be 100 or more I break out the E-Z Up.

 

[Carol 83]

I should have just written "Corona light" -emphasis on "light". It's really the only light beer I'll drink.

Nothing wrong with light beer, I prefer not having to chew my beer.