AusBonsai

Anyone have an idea why my scots pine leaves are dying, they seem to be hollowing, almost looks like dehydration.

Tree was replanted around 6 weeks back and was looking ok, started seeing new buds. Planted in equal parts pine bark, diatomite and Bunnings bonsai mix. Included some osmocote when repotted as well. Used seasol originally, and fertilised with Charlie Carp around 4 weeks after planting.

Have positioned in full sun, wondering if the couple 34 degree days in full sun, could have done harm. Planted in a black plastic pot, this would also heat up. Could this be the cause or something else, any suggestions?

Can't load picture from phone will post in the morning...

Close up of the needles

Hi Craig,

In the photo it looks like only the previous season's needles are affected and the newest needles are OK. Is that the same for the rest of the tree? Depending on how much of the rootball you removed during the repot it sounds like the tree is shedding old needles when the hot weather hit since it has less roots to support the foliage. A black pot wouldn't help either. Was there much mycorrhiza when you repotted? A healthy system of mycorrhiza will protect the roots from heat damage.

Matt.

Thanks Matt, result is pretty much the same across the tree, was hoping the repot was going to give the tree a bit of an extra push. Waited for the right time as candles where about to open.

When repotting cannot recall visible amounts of mycorrhiza, reduced from a large nursery pot plastic container to something around a third of the size. Outside of the mycorrhiza there were a fair amount of roots to support so was not too concerned at the time, you can see below the tree was healthy at the time of repotting (middle September).

Have moved the tree to a shadier spot to give it a chance to recover.

Hi Craig,

Summer kind of hit us early here in Melbourne, so the heat could be a factor. I repot all my Pines late June/July definately finished by mid August. Not sure where in Melbourne you are. I'm in Camberwell and find everything seems to be 4 weeks ahead of other people I speak to with regards blossoms,bud burst etc...
You also said you put some osmocote on it during the repot that could also be a factor as osmocote tends to be heat activated pending on how much and where you put it. Did you just put the osmocote on top or put it thru the soil mix? Don't laugh I know people who think this is a good idea? If its on top I would remove it. I never feed when I repot, I generally leave it a few weeks.
One question with regards Bunnings "Bonsai" mix have you used this before? I found it to be like really fine powdery mulch I bought a bag took one look and took it back to Bunnings so I haven't used it. Is the mix drying out between watering?
Are you still with Waverley Bonsai Club if so either take it to the meeting or seek out Ken I think he is the resident Pine guru at the club.
I hope it picks up nice bones.
Cheers

Thanks KIRKY, based Oakleigh South area, battling more with the extremes 34 one day and 20 odd the next, Melbourne weather is daft.

I've used Bunnings mix before, I find that it does stay too wet which is why I started with the bark and diatomite this season, others at Waverley warned me about the same when I joined couple years back. Much happier with mix, could probably do away with Bunnings mix altogether although don't mind the fines in small proportion, still finding my way.

Osmocote is in the mix, was not a lot based on quantities I have seen in some commercial pots. When I say not a lot would say around 1/5 cupped hand in basin of soil, is mixed through the mix. Only reason I started doing this is I heard of others doing so, previously all I used to add when still in South Africa was blood and bone meal at time of potting. Will reconsider going forward. Having said that have followed similar for other trees and they're fine, so perhaps just a case with specific tree.

Was considering foliar feeding every couple days with weak Seasol solution, and will wait and see what happens. As you say, nice bones, really would like this one to pull through. Time will tell.

Maybe try sit it in a tray of seasol solution Craig - not too deep, just enough that the soil can wick it up. That's been working well for me on newly repotted trees or heavily root worked trees. They hardly show any stress at all. You saw the size of the pot I put my cedar in and it didn't drop a needle after this treatment.

Hi Craig, in my experience it is not unusual for needles to brown off with a Scotts pine.. I worked mine pretty hard this year with needle browning off but it came back vigorously.

Thanks Jase, good idea... done. Have foliar sprayed with a weak solution of Seasol as well to mist the needles directly. Will repeat couple times a week, until I see signs of improvement.

Bodhi, thanks hope that is all I'm seeing, look forward to seeing some vigour.