Thursday, February 28, 2008

harvest of a European mountain ash

This is Sorbus aucuparia, the European mountain ash. It is called 'ash' because of the similar foliage. But it has nothing to do botanically with ash as it is from the rose family while the ash is from the olive family. Anyway, the reason this was repotted way too early is the fungus that attacks this species in the roots. If repotted in April like most other non-conifers the fungus will attack in May and in June the tree is dead. Repotting now is done on the hope that the wounds in the roots are already closed when it gets warm enough for the fungus. We also used good protectant on the wounds: milking fat!







12 comments:

Anonymous said...

Yes mountain ash is a misleading name, and ugly, Rowan is so much more elegant! Is this fungal problem ubiquitous?
Regards,
Matt

Walter Pall said...

Matt,

I really don't know whether it is ubiquitous, but I am afraid so. Fact is that in the past years I have lost five quite good rowans after repotting. It seems that the fungus gets into the system through wounds in the roots. If one repots in April then it takes until middle of May for the soil to get so warm that the fungus really starts to work. At the end of May the new foliage which looked so healthy starts to wilt. And by end of July the tree is dead. It seems that one cannot rescue the ree as soon as the fungus is in the system. A remedy could be to repot in fall or late winter. The wounds will hopefully be closed by mid-May. Another thing is to try to avoid wounds in the roots as far as possible. NO cutting of roots ona rowan. Normally In never bother to seal wounds in the roots. Just about all trees help themselves. But with a rowan I would cover the wounds. A big collected tree like this one unfortunately will hardly go into a decent pot without cutting a few roots though.

Walter

Anonymous said...

Thank you Walter, a cautionary tale. I am growing a rowan for bonsai at the moment and this piece of advice will prove useful, please post and let us know if this precaution is sucessful!
Matt

Cham said...

Walter,
Wouldn't a systemic fungicide works? What is milky fat? Is it butter?
How would you check if the wound is sealed without removing soil?
Cham
(Atlanta, Georgia)

Walter Pall said...

Cham,

maybe a systemic fungicide would work. A lot of research could be done. Milkng fat is what the farmer rubs onto the tits or his fingers when he milks the cow. It is like vaseline. It is meant to protect the tits. It also protects trees very well and is cheap.
I don't check whether the wound is sealed, I hope for it. Checking does not help it.

Walter

Pawel said...

What about the ointment Propolisad XX. This is also very cheap, and contains propolisan (ethanoly solution of propolis). Did you ever use that?

Walter Pall said...

Pawel,

I ahve no idea wheterh your thing could work. I personally never use such things. I work with trees every day and touch them all the time. I cannot afford to poinson my trees and myself.

Walter

Pawel said...

There is nothing poison. Propolis comes from honeycomb.

Kitsune said...

I've been looking to find a Rowan tree for use in bonsai for some time now (My son's name is Rowan). Though I haven't found the right stock yet, this is a great bit of info on the fungus, and one I'll keep well in mind!

Thanks Walter!

-Heather

Matt Williams said...

Walter,
One year on, can you tell me how this Rowan responded to this repotting so early in the season? I am keen to avoid the risk of the fungus to my developning Rowan.
Regards,
Matt

Walter Pall said...

Matt,

it is still very much alive. In a few weeks I will start to style it seriously.

Walter

Matt Williams said...

Many thanks Walter, I am glad that you have found a way to avoid the disease that seems to have killed so many of your previous Rowans. Hopefully my adoption of the same practice will prevent me having to learn this same hard lesson.
Matt