What exactly is the soil and what exactly have you added to this soil and over what time scale?
Thanks.

And I'd ask, is the raised bed on a solid surface, like slabs or concrete, or straight onto ordinary soil beneath?

is it a timber surround and if so has it been impregnated with anything

Good call!

I remembered my husband explaining to a friend that old railway sleepers or telegraph poles are the worst but also tannelised wood can emit nasties

the raised bed is on ordinary soil when we built the beds about 7years ago we had new soil delivered from a garden centre.the origianal soil is clay.
i have added blood and bone,chicken pellets,i have dug in bags of compost.over the years nothing seems to do any good.
The beds are full of ants and red ants i dont know if this could be the cause im not much of a gardener i would just love to see some nice plants growing in my garden.
i cant tell you over the last years how much i have spent on plants and still have nothing to show for it.The raised bed is in a south facing position.
please can someone help.

many thanks

The raised beds are brick built would we need to get rid of all the soil and renew..

many thanks

I'm stumped unless its lack of water ( but I'm sure you water them ), I hope Bamboo or Fractal can help , they are more experienced than me

If the soil is infested with red ants, they could cause a major problem as they secrete acid which can and does damage roots. However, that usually takes a while to affect a plant.
Very odd!

Shame you are right down in Essex. If you were nearby I would be tempted to call in and have a look as I am quite intrigued!

I wonder if the soil is at fault to start with? Might be worth testing it.

Well, back to basics: 1. When, as in what time of year, have you planted things in the bed? In summer or Spring? 2. And what, precisely, have you tried planting? Summer bedding? Shrubs? and 3. How have you been watering, and how often?