whats up with the Rowans?

[Gary.ric]

I've been working in the north somerset/bristol/bath area and have noticed a lot of Sorbus aucuparia looking none to healthy, anyone else noticed this and any ideas what it may be? (sorry got no pics)

 

im pretty new to this so am not great at pests, diseases and disorders, it looks like wilt but no leaf drop, the leaves look dry and scrunched up much like a neglected plant on a window sil?

Edited July 17, 2009 by Gary.ric
bad spalling!

[TimberCutterDartmoor]

We've had bees in the media recently, won't be long before trees are in it in the same context - climate change or whatever else is confusing nature. V sad...

[RobArb]

black fly????

[Highland Forestry]

lack of water possibly...

[gmanntpo]

What enviroment were they growing in?

 

Were they street trees? There is growing evidence that S. acuparia will establish but when maturing, their roots can't take the higher tempertures under tarmac/concrete..

 

There are many declining street tree Rowans where I work... They get to age 10 years+ and then decline & die.

 

The research on the the root issues seems pertinant I reckon....

 

 

Don't forget that research has shown that the average temp under man made surfaces provides ideal root development temps... but it looks like its too hot for the Rowen!!

[Gary.ric]

i have seen some in street settings, under tarmac and small grassy areas but also in gardens and parks. They've all looked pretty unhealthy.

 

Looks like aphid probably but just wondered why its only Rowans affect.

[gmanntpo]

Hi mate

 

Hopefully the infestation of aphids has peaked! I doubt that alone will be too detrimental to the overall long term tree health.

 

Chers dude.

[Luke Quenby]

Rowans don't like heat, and like a fair bit of water, they quite often look poor in a street situation in the summer

[janey]

Over the past few years, street Rowans are failing badly. They seem to be sucumbing to a combination of heat / drought stress and basal cankering. Most of the aucuparia (Rowan) type species and cultivars I regulary see are suffering, especially S cashmiriana and S hupenhensis, while S "Cardinal Royal" and S "Street Wise" seem to be effected less. I've stopped planting aucuparia types as a result and tend to stick with S "Browers" which still seems to be doing well.

 

A lot of the aria (Whitebeam) types are failing as well, again with basal cankering but with sections of the crown dying in succession rather than in one go.

 

Other than good young tree husbandry and choosing more robust spp's and cv's, I don't think much can be done about this.

 

Tis sad