Rejuvenating an old apple tree?

It could be struggling for the simple reason that it was a random seedling that doesn't necessarily inherit much resistance to disease. A 30-year-old seedling ought to be in the prime of its life, with another 50+ years of life in it. It sounds like your tree will always be weak and sickly.
I'd suggest, later in the summer, trying to bud-graft onto a strong piece of rootstock because it seems to lack vigour (MM111 or M25 should get it moving), and make further grafts onto strong rootstock during the winter.

If the tree must be saved........

Clip off the mildewed bits. They will shrivel and die anyway, so best get rid before the mildew spreads.

Give the tree a good hosing-down with a garden hose, to blast off aphids and especially woolly aphids.
Woolly aphids that won't let go, or are hiding in cracks should be brushed off with a stiff brush dipped in meths (if the brush doesn't crush them, the meths will poison/suffocate them).

After getting rid of aphids and dead bits, I'd say that, given its sickly condition, you'd be best to "nuke it" with some potent fungicide, to get the diseases under control.
I'd caution against Bordeaux Mixture in case the tree is sensitive to copper (a few varieties don't like copper and you don't want to stress the tree further).
Don't worry about insecticide; the hosing-down and meths will keep aphids sufficiently at bay.

Don't feed too much nitrogen, but the tree would benefit from a modest amount of a balanced feed. I'd suggest a very light sprinklig of fertiliser and a good mulch of compost for moisture retention and slow nutrient release.

.........

Any chance of some pictures (close-up and full-tree pics), to get an idea of just how sick it is?

Cheers FB...........I'll see what I can do about piccies!

There you go FB.

Whats the prognosis?

Hmmm.....

Overall condition is quite poor, but the trunk looks sound, so the tree could be saved, but may need a regular spray routine to keep mildew at bay.

It looks - as you said - as if it is riddled with powdery mildew and has been for many years. There are a lot of dead, lichen-covered twigs, which were probably killed by mildew in the past.

Mildew is a crippling disease to susceptible varieties where conditions are right, and I suspect that your tree would be much larger if only it wasn't so prone to mildew, or if grown in a higher-rainfall location.

The surrounding grass looks quite pale coloured. Is there a problem with the soil, such as extreme pH, shallow soil or otherwise poor/depleted soil?



Personally, I'd get rid of the tree.
But as you may have other apples anyway (although this seedling is acting as a reservoir of mildew) and you may be "attached" to this tree for sentimental reasons, then I'd suggest several possible things that each might make it a little happier and more productive.....

1.
Clear the grass away from under the canopy spread and if something must be grown underneath, make it less competitive than grass. Watch out for the trees roots just below the grass; it needs all the roots it can get, to bring up nutrients to try to out-grow the mildew.

2.
Mulch the tree well and often, all-over the area under the branch spread (give it a good watering if you're having a dry spell like me). The extra nutrients and moisture retention of a good mulch should reduce the amount of mildew infection by making the tree less stressed. Vigour will also be improved, which might allow re-growth of all the dead and diseased bits. Keep its vigour up with good mulching, so that the mildew might be out-grown, even if the tree is not able to "resist".

3.
Remove all dead branches and mildewed leaves.

4.
Remove further mildewed leaves as soon as seen; they will die anyway and will re-infect the tree, so they're best got rid of.

5.
Next winter, prune the tree quite hard, ensuring that the ends of all branches are removed. The tips of twigs is where mildew mostly hibernates. Twigs carrying mildew over to the next season can have a whitish appearance during winter, plus, if infected with mildew, the topmost bud often remains part open all winter, plus the mildew-infested buds open slightly earlier in spring, to ensure that spores are scattered over the healthy leaves as they emerge. Young leaves are most vulnerable. Trees on poor and dry soils are vulnerable. Low rainfall increases mildew activity.
Perhaps consider using some fungicide for 2012, to allow it to re-grow branches after the pruning, without them getting infested with mildew.

6.
Periodically hose-down the tree in dry spells; the wetting action on teh leaves might reduce mildew infection, since mildew prefers hot, dry weather with humid air. The hosing-down should also knock off a lot of aphids/caterpillars. the water will drip off and keep the soil moist, which will also help reduce mildew.

7.
Winter prune only, other than to remove diseased leaves or twigs.

Thanks F.B.
I would like to keep the tree if possible.
I bought the house about 8 months ago, don't live in it yet (under renovation) so the garden hasn't been touched. The grass looks yellow because its moss laden and I'd just strimmed it!
I have a garden plan in my minds eye and would like to keep any 'fixed' plants and work round them.

I'll do what you say though and get back with a follow up piccie next year showing it in all it's glory after renovation.(Snadges seedling)!

PS Apparently the reason its lying over to one side is that the clothes line used to be tied to it!

You could put in another and get a hammock!

Snadger-any update on the health of the tree above? Did you stick with it or did you pull it out?