What is this on the leaves of this plant?

Could it be a leaf miner of some sort? Not sure - I hope one of the experts on plant problems will know!

Is leaf miner the one that makes the tracks all round the leaf - like tunnels? I don't think so, as these are sort of splotches. I hope someone has the answer, as I'm really upset by it - the bed looked lovely last week - and now the plants look terrible...:-((

Yes, I'm sure you are - I'm sorry. I hope so, too. We do have several members who 'know' about this sort of problem, so don't despair.

What's above the plants in that bed? A tree or something, anything that might drip onto the plants?
This is leaf damage from something (never let it be said I don't state the b...ing obvious) but from what I can see of the top leaves in the pic, they look healthy. Are the plants growing well otherwise? It could have been something grazing on the leaf surface, sunburn from being wet in hot sun, liquid feed splash, weedkiller splash. All of that assumes you never saw anything in, on or around the plants that could be the cause.

If the answere to Bamboo's suggestions is 'no' then could it be a lichen growth?

It looks like water damage or hail stone damage. Next years leaves should be fine. This looks like a Heuchera and may not like hot sun on its leaves when wet.

Could it be mildew I have had a lot of plants covered in it this year -acanthus - sweet peas and clematis.

Thanks for all the replies.

Bamboo - there is a nasty old ivy on the fence behind the plants which I hack back regularly. You're right - I never saw anything around the plants to indicate it might be a pest of some sort. I think you're onto somthing about the water scorching the leaves.

Bulbaholic - does lichen grow in the space of a week? The plum tree closest to the bed (about 4 feet away) is covered in lichen.

Volunteer - well spotted, it is a Heuchera, and actually the bed is positioned so that the sun literally pops over it at midday when I suppose it is at its hottest. The leaves on the pelargonium are corrugated (is that the right word?? Crinkly anyway!) and those leaves are the worst, as presumably they will hold the most water. Its also interesting that this happened after I watered using the can, and not the hose which just sits at ground level not touching the leaves.

Cammomile - mildew is powdery as far as I know, and these leaves are just brittle. Would mildew make the the leaves brittle?

Spritz - thanks for the general words of sympathy,and listening to me moan!

Can I assume I would be alright to take cuttings even if the leaves are scorched?

A tip then - when you water with the can, take the rose off, apply directly to the soil. And yes, you can still take cuttings, just try to use the healthiest, least damaged leaves.

Thanks Bamboo - how annoying. I hope they all recover. i'm just annoyed at myself for being careless. Interesting that this has also happened now and in spring, as presumably the heat over the summer meant the water evaporated before the sun hit the bed.