I think the statement 'acid in it' is a bit overstated, Dragonfly. Certainly the soil will be thin and undernurished so you would do well to bulk it up with plenty of compost, either garden compost or from the garden centre. It will be fine for the climbers that you have named.

And if you ever want to test the acidity of soil most garden centres will sell a handy little metre with a dial and prongs you insert into the ground, and you can then read off the pH.

Dragonfly, you are aware that the three climbers you mention need something to climb up?

the soil may well be acidic from the needle drop over the years but the amount of acidity will not be too great. enrich the soil with leaf mould/compost etc to give extra nutrients before planting.

To: Seaburngirl, Moon Growe, Steragram and Bulbaholic

Thank-you for answering my query so soon. I shall now have confidence in planting the climbers mentioned. Also the little gadget from a garden centre for testing acidity would be helpful in any case for other parts of the garden, so might consider. I thought that the old droppings from the trees would actually be a leaf mould of sorts but will compost accordingly. And the climbers will be attached to a strong trellis which has been erected close to the neighbour's concrete wall. Many thanks to all of you.

If you have all three of those on the same trellis you'll need to watch the ivy or it will take over.

And if the test kit indicates acidity then you can always add lime. My tester tells what amount to add to bring the soil up to neutral.

Thanks for your latest comments. I would dearly love the ivy to take over, it is evergreen and the birds will love it for nesting. I shall keep an eye on it and trim accordingly.

If the ivy takes over it will crowd out the clematis completely.

Not only the birds, Dragonfly, but also the holly blue butterfly, which uses ivy for part of the year. Also various other beneficial insects. For several years I had wrens nesting in my thick ivy on the back fence, but sadly, I haven't seen a wren in the garden for at least a year. The decline in birds around here is alarming so more power to your elbow!
Moongrower's right about the clematis--it might be best to plant that elsewhere!

O.K. Pennyfarthing - I see what you say - thanks