What's wrong with my plants :-( ?

I've got several plants that are looking really unhappy/close to death.
Plants in pots are all doing fine, these in a bit container with plenty of room to spread their roots, all looking v sickly.





2 x Dahlias started going brown about a week ago, now almost completely crisped and dead. What's wrong with them? What should I do for them or do they need pulling and throwing in the bin?
Lupin got bad whitefly but was sprayed and they went but then it just carried on deteriorating as shown until I had to cut off all the stalks and leaves.
Rose - looking quite unwell but have fed with Focus Unique Liquid Concentrated Fertiliser and it's rallying. I think I need to cut it back quite enthusiastically as it's v spindly but since using the Focus stuff, new shoots are coming out from nearer that bottom which is good - intention is to feed this (each time I water?).

My suspicion is that my soil is not right though. Looking at the hosta for eg, I feel it (and everything else) could be looking better if that was better. When I put in this 9 ft long by 3 ft deep by 3.5/4 ft high container, I put old torn out turf in the bottom and then I had a mixture of topsoil and compost. Does anyone have suggestions for what I should put in right now - well rotted manure???

Help, I feel everything's dying on me!

I'm not sure I've managed to add the pics - possibly don't have enough posts yet or something, so I'll post what I can for now and see how it goes.

 

Yes indeed JWK, about 10 miles south east of Birmingham.

I just tried again, it tells me amongst other things that I don't have enough posts so I'm a bit stuck - unless I make another, random, post then try again?!

 

I would contact admin about it @BlackCountryGardener I don't think there's any reason why you couldn't upload photos.

 

Will do, thank you.

 

Without seeing the picks yet, I'm going to make an educated guess.

When were they planted? And into what soil?

If it's plants that started in a pot, in compost, and you put them in a hole in clay, two things happen. Firstly, the roots often don't penetrate into the clay soil, but just stay in their original compost. They will eventually, if the surrounding soil is moist enough, but it's kind of a race against time, from stretching their legs, before drying out.

The other bad thing that happens is the clay soil literally sucks the moisture out of the compost the plant is in, as the moisture will always move from larger particles in compost to smaller ones in clay soil. With the unusually dry year we've had so far, there's a lot of capacity in the soil to suck water out of anything moist in comes into contact with. Incidentally, this is the very reason why I can pour an entire watering can on one spot at the moment and it just disappears without a trace.

Watering is the obvious answer, but the ground is so dry right now it feels like we're fighting a losing battle.

 

Vine weevil perhaps?

 

And if you are linking to a photo on the like of Imgur or a website then you use the Image icon at the top of the screen.

 

Thank you, yes, this is what I was trying to no avail.

 

Hi. With absolutely NO doubt, I AM getting a message saying 'you don't have enough posts', I honestly am not making this up. I'd attach a screenshot of the error message, but..... Please let me know what else I can do, thank you.

 

How odd! Have you been naughty online? Websites sometimes have a mind of their own. I have "liked" all your posts to see if that helps. Perhaps you could respond here a couple of times to take you to 10 posts, spamming is allowed in these situations.

Looking forward to seeing your photos, the going ons sound like a mystery.