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japanese maple leaf burn and pruning

Posted: December 15th, 2013, 1:45 am
by badabing888
HI Everyone,

I got thrown in a japanese maple when i bought a jbp stock today and i'm a im a bit stuck on where to go from here.

It appears to have bad leaf burn the nursery does over head watering, combined with this week being close to 40 everyday and the hot winds in perth generally causing this with maples i've been told that if you deleaf around this time of year when it regrows its second set these are thicker and more hardy. Thoughts?

I'm going to keep it in its training tray so the question is,

is it safe to de-leaf and start to cut the currently long branches at the same time? it does appear to have some potential once it is pruned to be less top heavy and the elongated branches are shortend and a greater number of finer branches grown.

Sorry about the pic quality !
photo 1.JPG
photo 2.JPG

Re: japanese maple leaf burn and pruning

Posted: December 15th, 2013, 8:04 pm
by shibui
You can defoliate and new leaves will grow but the only way they will be hardier than the first lot is if the first leaves grew in a shady area and the new ones open in a sunny area. Maple leaves are still maple leaves after all.

You can prune your tree as hard as you like and it should re sprout. You can also prune and defoliate any leftover leaves at the same.

Burnt leaves are not caused by overhead watering. It is caused by not getting enough water. This one is in a wide, shallow tray which will (and almost certainly has) dry out very quickly in sun and heat. Sometimes in hot winds maples just cannot pump enough water to the leaves to keep them hydrated and cool so some will burn like this even if the soil is moist. Proper watering, protection from hot wind and maybe a little afternoon shade should prevent most leaf burn.

Re: japanese maple leaf burn and pruning

Posted: December 16th, 2013, 12:53 pm
by thoglette
shibui wrote:Sometimes in hot winds maples just cannot pump enough water to the leaves to keep them hydrated and cool so some will burn like this even if the soil is moist. Proper watering, protection from hot wind and maybe a little afternoon shade should prevent most leaf burn.
+1. Hot, dry winds are The Enemy(tm). Dappled shade is better than full sun in summer. My seedlings live in a glass house in the shade - only way they will survive summer here.

Re: japanese maple leaf burn and pruning

Posted: December 16th, 2013, 1:23 pm
by Naimul
Im glad im not the only one, this is the first time its happened to my maples, they look terrible :(

Re: japanese maple leaf burn and pruning

Posted: December 16th, 2013, 2:59 pm
by Eusto
Happened to me too. I defoliated and 2 weeks later she was budding all over again. Its in part shade for the summer. Mostly shade.

Re: japanese maple leaf burn and pruning

Posted: December 16th, 2013, 4:23 pm
by mugen
Perth is to hot for Japanese maples Imo. But if you insist on growing them here keep them in full shade and shelter them from the easterly. And I suggest getting hold of some vapor guard and spraying the foliage early spring mid summer and autumn.

Re: japanese maple leaf burn and pruning

Posted: December 16th, 2013, 7:54 pm
by deejay335
Hi Mugen - after seeing your comment on Vaporgard I looked it up. Seems interesting, and I have some issues with wind due to being on a small hill farm in rural Victoria so my plants are all pretty exposed no matter what I do. At first glance, the Vaporgard may be good to protect my plants a bit more. Do you actually use it, and does it deliver what it promises? Is it very expensive and does it last for a reasonable time?
cheers
Don

Re: japanese maple leaf burn and pruning

Posted: December 16th, 2013, 11:25 pm
by quniverse
Hi

I too live in Perth and was wondering if anyone has tried those small plastic greenhouses about 1.5m tall to prevent wind burn on maples (obviously kept in the shade)? I live in Perth and the wind is usually strong/hot no matter which direction it comes from.

I was wondering if the size of the greenhouse can cause issues?

I've also found a kitty litter tray about half full of water is a good method of keeping a smaller tree hydrated. Best to make sure the water level goes almost all the way down before refilling and always mist the plant on a hot day assuming its in the shade.

I wonder if Vaporgard is available locally here or is it an online purchase?

-Sean

Re: japanese maple leaf burn and pruning

Posted: December 17th, 2013, 12:42 am
by ADO
quniverse wrote:Hi

I too live in Perth and was wondering if anyone has tried those small plastic greenhouses about 1.5m tall to prevent wind burn on maples (obviously kept in the shade)? I live in Perth and the wind is usually strong/hot no matter which direction it comes from.

I was wondering if the size of the greenhouse can cause issues?

I've also found a kitty litter tray about half full of water is a good method of keeping a smaller tree hydrated. Best to make sure the water level goes almost all the way down before refilling and always mist the plant on a hot day assuming its in the shade.

I wonder if Vaporgard is available locally here or is it an online purchase?

-Sean
Those plastic 'greenhouses' are next to useless and may cook your plant in this heat. you could build a mini-shadehouse with a simple frame and 50% shadecloth draped over it.

Re: japanese maple leaf burn and pruning

Posted: December 17th, 2013, 1:34 am
by mugen
deejay335 wrote:Hi Mugen - after seeing your comment on Vaporgard I looked it up. Seems interesting, and I have some issues with wind due to being on a small hill farm in rural Victoria so my plants are all pretty exposed no matter what I do. At first glance, the Vaporgard may be good to protect my plants a bit more. Do you actually use it, and does it deliver what it promises? Is it very expensive and does it last for a reasonable time?
cheers
Don
hi don yeah I have used it on larger maples and it is effective at minimizing scorching from our hot easterly winds here in Perth. Worked quite well but you have to spray before the scorching occurs obviously, lasts for most of the summer but you have to apply it new growth as it comes out. As far as cost goes I'm not sure my boss payed for it. I've used it on Japanese maples, trident maples, Acer ruberum, Betula pendula and cut leaf birch. It basically creates a layer on the leaves that slows transpiration the leaves get a bit glossy but not noticeably so. We spray it on three times during the warmer months. We water with sprayers below the foliage so if you get heaps of rain where you are might need to apply more often.

Hope that helps Don :tu:
Jac.

Re: japanese maple leaf burn and pruning

Posted: December 17th, 2013, 1:39 am
by mugen
quniverse wrote:Hi

I too live in Perth and was wondering if anyone has tried those small plastic greenhouses about 1.5m tall to prevent wind burn on maples (obviously kept in the shade)? I live in Perth and the wind is usually strong/hot no matter which direction it comes from.

I was wondering if the size of the greenhouse can cause issues?

I've also found a kitty litter tray about half full of water is a good method of keeping a smaller tree hydrated. Best to make sure the water level goes almost all the way down before refilling and always mist the plant on a hot day assuming its in the shade.

I wonder if Vaporgard is available locally here or is it an online purchase?

-Sean
I think we purchased the vapor guard from Mirco brothers from memory.

Re: japanese maple leaf burn and pruning

Posted: December 17th, 2013, 8:21 am
by deejay335
Thanks Mugen - appreciate the info. :)

Re: japanese maple leaf burn and pruning

Posted: December 17th, 2013, 6:20 pm
by SeanBarracudA
I have just moved all 20 or so of my pre bonsai maples in to dappled light / shaded area for the remainder of the summer.
A few leaves had started to burn but nothing to worry too much about.
Also good to keep maples out of the sun during the heat because wire will burn the poor trunks and branches.

Re: japanese maple leaf burn and pruning

Posted: December 19th, 2013, 8:06 am
by thoglette
ADO wrote:Those plastic 'greenhouses' are next to useless and may cook your plant in this heat.
If in the sun WILL cook your plants. However I've had success using green houses IN FULL SHADE.

Anything you can do to lower transpiration (ie. less wind, less heat, less sun) is good for the next two months.

If your aircon is off then moving your plants inside during the hot hours of the day is also an option.

Re: japanese maple leaf burn and pruning

Posted: December 20th, 2013, 7:53 pm
by badabing888
Hi Guys,

Sorry for the late replies to this one was sent over to the east coast in a rush to the east coast for work.

Some awesome information here, before i left i moved it to an undercover / protected patio area and i can see some new growth starting to come through now that isn't burned , the area is usually 6-7 degrees cooler then being in full sun so i'm hoping that will help. I've also now fully defoliated so lets see how that turns out!

Never thought about tray depth but it would make sense that it wouldn't hold as much water as a deeper pot i'll keep an eye on moisture levels. interesting idea vapour guard worth checking out! experimenting with a few of these things should help the situation.

Regards

Daniel