Sick Sumach

I have two staghorn sumachs (still thin, about 7 ft high) growing just fine in my borders. But just toward the end of summer the leaves on both of them start drying up and browning. It starts w leaves drying then stems and works its way down the plant from the top. I've had to cut it back to healthy tissue.
It happens just before the glorious colours come out.

Can anyone tell me what the problem is? I understand it's drought-tolerant so it can't be lack of water. Besides, we've had such a wet summer. Also, I have no suckering problems w them. I have photos but it says I 'may not' post attachments.

 

Hi Mrs Flowers.

If you can host your photos on another website such as Flickr you can link to them here, using [ img] tags. Just a thought.

What type of soil do you have? If it's water retentive then it may be a case of waterlogging due to the amount of rain we've had over the last two years. If this is the case I'd suggest adding a lot of organic matter into the soil to break up the particles as well as feed your plant vital nutrients that it may be missing out on. Apart from this and without pictures there's nothing much more that I can suggest. Have there been any major changes to your garden at all within the last few years?

 

Hi Treesurfer78
I have hosted three photos on Flickr. Thanks for that suggestion. It wasn't too difficult.
http://www.flickr.com/photos/31131028@N07

I have a woodland garden in London, slightly acidic with a 6 -12" top layer of fragrant crumbly friable soil on top of typical london clay. The garden was untouched for at least 14 years before I started gardening it 3 years ago. It has a big deciduous tree canopy of mostly ash (suckers etc) pears, plums and a few unknowns.

Of the two, one is under tree boughs and not getting too much water, the other not under and therefore all the rain we've had. One was moved 2 years ago from another location, the other a cutting .
Both have branches/trunk no thicker than 3/4" - 1".

Although not regularly, I do feed all my plants and shrubs a few times in the growing season.

The soil never looks water-logged or gooey.
Thanks for your help.

 

Hi Mrs Flowers,

Thanks for the photos. It looks like your plants are showing leaf chlorosis - a yellowing of the leaves follwed by withering and dying. Chlorosis is caused by many things inc. soil compaction, incorrect soil pH and nutrient deficiency (mainly zinc, iron and potassium).

I wouldn't suggest applying any fertiliser now as the plant will be gearing down for the winter. Instead try and aerate the area using a garden fork, carefully avoiding damaging the roots. Apply some organic matter in the way of well-rotted manure or similar as this will provide a good supply of the plant's vital nutrients as well as sort out any soil drainage problems. In the spring you can add plant feed as you have been doing.

Hope this is of some help to you.

 

It could also just be wind scorch

 

I'll give it a go. I also will consider the wind factor.

Thank you.

 

Or waterlogging.

 

I think wind scorch would only be a problem if it was an open location. A woodland garden with a tree canopy as this one is probably would actually help to avoid this occuring. Waterlogging could be a problem, but Mrs Flowers has already said the ground does not appear to be saturated.