Raised beds dry out quicker than the flat unless your on really free draining soil, they also heat up much quicker so you can save a few weeks if your " OOOp Norf ".
The best thing I found is that in a raised bed you can create a fab soil ideal for your crops which if your in a granite rock or a wet heavy clay area is handy .
Over 16 years ago I made several 2 foot deep by 12 by 4 feet raised beds out of tanalized 4 x4 inch square posts and one inch by 4 inch decking boards . There was a post every two feet set in concrete to stop the walls bulging .
All board work was screwed to the posts with decent length stainess steel coach screws & big flat stainless washers .
Four years ago I happend by the old place , the beds were still there in use. Cheekily I stopped and called on the people there ( not those who had purchased our home ) they were very pleased with the beds and the layout of the garden for the spaces inbetween were grassed and strimmed easily as well .
Initally it seemed expensive but when I sustained a spinal injury from my day job in 1995 they were a god send, I could still grow things without hardly any bending .
This has led to me going OTT in my new home and having some 900 mm high beds built in class B engineering bricks as linked 900 x 900 cells in the back and front of the bungalow .
These new brick beds were built this year , I was late in getting the beds into crops ( last 10 days of July )because the builders were way over schedule by four months .
I am trying out the " square foot gardening " methods as I see no point in my struggling trying to dig over yards of soil that will not be used to grow stuff in .
There is a book about it , it is called by the same name ..is for USA & Canada but easily transfers to the UK.
I have however managed to grow some great turnips to 3 inches across without a woody one in sight .
I have had numerous three inch long by 1 1/4 inch in diameter radishes ., again no woodyness .
The lettuces & swiss chard are fantastic ..
Several hundred late carrots one seed every three inches and four inches between rows .
i have made a guage rod by drilling 3 mm and bigger 5 mm holes in 36 inches of aluminium angle.
One side gives three and six inches , the other side gives four and eight inches ..it was a doddle to sow the seeds ..took about four minutes ..I have no thinning out so reduced carrot fly probs & no disturbing the other carrots .
I've used the guage to sow /plant out every other veg as well
I have about 100 beet root.. now over an inch indiameter .
I've also put in cabbages, dwarf kale , dwarf sprouts and over 100 over wintering onions .
To keep my lass happy because of the behind schedule I have also used four of the rear garden beds for flowers that have bulbs , corms or tubers till the front beds and parking spaces are fully finished .
Weeding takes a few minutes by hand ..no hoeing . its easy to sprinkle epsom salts or fertilizer etc. on the beds
When a crop is taken out I've been using a trowel full of well composted horse muck and dug it into the area then re sown or planted a seedling straight away . That way there is little chance of weeds coming up.
Obviously carrots & other forking root crops won't be going into the manured beds till it has been used for nearly a year .
I designed the garden to have the beds to be near the bungalow because I'd rqather go out aand collect veg close to the bungalow than have to go 50 mtrs down the garden in rain or snow etc to do it.
All the beds were set up in layers , on the bottom is 4 inches of soil , 4 inches of sharp sand , 4 inches of well composted ( 3 yrs or older horse muck with straw ) then repeat with soil, sand ,horse muck till the bed contents were 9 inches from the top then added a five inch topper layer of bagged quality sterilized loam.
I've so many worms in the beds it's amazing.