Raised beds or beds dug at ground level? What's best?

You can start at ground height and build up by the application of muck and compost and other organic materials.

No dig can be done too
Lazy beds
or lasagna beds

Traditional raised beds would require plenty of good soil or compost to build the level up. Expensive but quick if you buy big bags of top soil.

Other methods require materials being added but they are often cheaper than top soil. Not as instant if you have to collect them together though.

https://www.youtube.com/watch?v=OCyum7tPMP0

Raised beds warm up quicker and dry out quicker too. They can be useful if you have very thin topsoil and want to add to the depth of soil, for perhaps carrots and parsnips. Where are you and what is your soil like? Also useful if you find bending difficult. I'm sure there are plenty of threads on this already if you search for them.

I've done shallow raised beds for the most part, other than my root veg bed, which will be about a foot high for some nice straight roots. I did this on my allotment so that I could separate planting areas from walkways, as I'll be covering the paths with weed fabric and bark chips. For me it's just a way to keep weeding down, although it's actually increased the work for me as I'm breaking down pallets to build them

If the soil is ok then there's no need to buy wood to make sides or soil to fill raised beds

They may be worth making if you have bad soil, or a drainage problem that is not easily solved.

I have heavy clay soil. I created raised beds by digging out permanent paths, one spade's depth, and putting the soil on the "beds" inbetween. So as much as raising them, I was mostly lowering the paths. The beds drain more freely as a result (in effect they drain into the paths of course). Over the years I have added compost and manure etc. which has raised them a bit more, but I haven't added bought in soil / bagged compost etc. They are only raised a few inches, per se.

I started off with what are termed "lazy raised beds" which is to say they had no timber sides. Slight downside with this is that the "shoulders" of the bed are not easy to plant on, and the soil tumbles onto the paths a bit - so every other year, or so, you have to spade it back onto the beds. Not a big deal, as such, but it doesn't look pristine like a "shiny new pin". However: costs nothing , and if you decide you want to change the layout, completely, then there is no timber in the way etc.

I have since added timber sides to the beds and made them look "new pin" smart

If you are on light / sandy land then I doubt that raised beds have any benefit - unless you need them to look uber-smart (hard in a veg patch whatever you do!!) or have trouble bending / kneeling etc.

My beds are 4' wide - don't make them wider, that is max that you can easily reach from each side - and my paths are wide enough that I can kneel in them without my knees or feet squidging against the edge of the bed. Having paths wide enough to get a barrow down is pretty important too.

Critical that you never EVER walk on the raised beds. They benefit from not being compacted (whether you dig them, or adopt a no-dig policy). Personally, even for No Dig, I would double-dig them just the once, at the outset. Double dig is two-spade's depth, and being careful not to mix top-soil with sub-soil, and has the benefits of improving drainage, getting air into the sub-soil, and provides loose soil for roots to get down into.

Raised beds are good if you have terrible soil (Builders rubble or impossible clay, permanently wet etc, Also if you have trouble bending they are a boon. I find they get less weeds and you make the soil contents into whatever you want. My beds are about 10inches and the bottom half was filled with cardboard, paper leaves and half made compost, that all holds moisture and encourages lots of worms, the top half consists of top soil and compost, some home made some bought. You could if you wish dig them with your bare hands but I dont dig them. I top them up with compost each year. Then I think they look tidy and organised. I made mine out of second hand decking and tried to keep them all the same size, mostly I have them 2 boards deep but I can add another if i need it deeper for carrots etc as they are interchangeable. Having the same size also means if you make a hoop frame to fit it will fit any bed. There are different thicknesses of decking I use the stronger 36mm and also have a central cross member to stop the bulging.

I disagree with you on that point (alone ). I think if there is builders rubble, e.g. on a New Build, it needs to be got out. Never going to make a garden with all that buried junk interfering with drainage / root penetration etc. Dread to think of what cowboy builders might also bury that is toxic etc shouldn't be allowed in the first place IMHO.

I think next episode (so that would be next Thursday on BBC Scotland and Sunday week on BBC2 around 8am I think) of Beechgrove has a bit on sorting out the builder rubble in a new build garden. I'll be interested to see if they do it Kristen's Way (tm) and get it all out.

I have both, which have been reclaimed from grass. It took me 3 years to get on top of the grass by just digging and removing bit by bit. So last year I decided to reclaim a bit more with raised beds, these I dug over, covered with a good layer of cardboard and top filled with a good foot of well rotted manure. I had an excellent crop out of them the first year and they were a lot easier to work over last Autumn and this spring. I have a few spots where the grass has found a way through even though it was dug over, but on the whole the raised bed is easier but more costly.

So whats more important time or money?

I chose my words badly by saying builders rubble, in my case I have an area that is shale, no soil just flat rocks 3 to four inches long, quite useless for growing in. but there are many reasons the soil below might be unsuitable.I also have a 5ft high wall that was backfilled on one side to the top with bricks and rocks, I aint about to get 5ft of bricks out.But yes builders rubble can containt paint tins and all sorts of chemicals.