Sickly magnolia grandiflora

I have a Magnolia grandiflora growing against a wall in a west facing corner of my garden. It's a beautiful plant (well, tree, really) but is, to say the least, unsuitable for my small town garden. However, it was a present from my mum, so I couldn't be ungrateful, could I? Anyway, it has done quite well so far, despite having to be chopped about from time to time when it outgrows its allotted space. Over the last year or so, however, the leaves have become more and more yellow and sickly and it is now looking very sorry for itself.

Could my chalky soil be the cause? I know that some magnolias don't like it, but since there is a large specimen growing quite happily just down the road with no obvious mollycoddling it seems odd that mine should be affected. Would a good feed and compost mulch be likely to cure the problem, do you think?

 

It's more than likely your magnolia is suffering from chlorosis an iron deficiency that reduces the production of chlorophyll. We had one that suffered from the same problem. The solution is to treat with chelated iron or ferous sulphate.
Your chalky soil won't be helping.

Here's a link which may help -
http://www.mortonarb.org/tree-plant-advice/article/662/chlorosis.html

 

Thank you, Dave.