Best water-soluble fertiliser...

For what plant/s?

Broad-leaved evergreens, ivy in particular.

If your ivy is in the ground, it doesn't need fertilising at all - a general application of Growmore granules in spring turned into the soil at the base will be fine. Even in a pot, it won't need much, it'll take over the whole pot inside two years, but if you do want to feed it, something like Miracle Gro general purpose, the blue soluble powder, maybe once in Spring, and again a month later. Do not feed now. Same rules apply to other evergreens, unless they're acid lovers, when you might want to use an acidic feed, though its not essential to do so.

Thanks, Bamboo. The ivy covers most of one wall of my house, and is looking very sorry for itself (no diseases that I can see; it's just that a lot of the growth has turned brown - plus it's festooned with spiders' webs that you wouldn't believe the size of, making it look even worse!).

I can't use granules because there's currently a slabbed path over the root area (slabbed path to be removed in 2-3 weeks, though, and some decent soil put down and worked before gravelling). I've been watering it regularly over the last three months, but so far it's making no difference, which is why I was considering feeding it with a water-soluble fertiliser. I know I should have done it in the spring, but I kind of assumed new growth would appear, as it always has done, but it's put on hardly any at all this year.

Anyway, I guess there's nothing much I can do now till next spring, except continue to water it (and maybe attack it with the hose-pipe to remove a lot of the dead leaves - and the spiders' webs!

It sounds as if something's happened to your ivy - other than drought, which might make some leaves curl and drop off but is unlikely to kill it, there's nothing that would cause this, certainly not lack of fertiliser. Check the woody parts, see if there's any damage anywhere, inspect the backs of leaves and green stems for signs of something or other. Strimmer damage near the base isn't uncommon, for instance, and that could cause a bit of dieback.