[shokkyy]

One of the apple trees in my garden looked extremely poorly last year, with extensive yellowing on the leaves. This year it looks a bit better but still shows yellowing, although it has just given us a very good crop of fruit. When I look in my Hessayon book it says this yellowing is a symptom of iron deficiency, but I'm very puzzled by that. There's another apple tree and a pear tree right next to it, both of which are strong and healthy with no yellowing. How could iron deficiency be so localised? And I thought iron deficiency was normally caused by heavy rain washing nutrients out of the soil, primarily in light or sandy soils, but my underlying soil is heavy clay. So why would this happen to one tree and not the others, and why on heavy clay?

[Goosegirl]

I have heavy silt akin to clay and I have seen it on many plants, as it seems to lock in the accession of iron. Where I am, I can have localised pockets of peat amongst the heavy silt, and I know people have had problems with a plant, have moved it a couple of feet, and it's been ok. I would suggest giving it a good sequestrine feed in a foliar or root drench now before winter, and see what happens next year.

[azubah]

Could you get results by throwing a few rusty nails around the tree? Might be a cheap long lasting cure...