Raised Beds - not always a good idea?

All my veg are in raised beds and you are correct that they do need more watering, however you can plant closer together which means more crops and less weeding.  They are also much easer to dig over so to me the advantages outweigh the pitfalls.  I have found the shorter varieties of carrots do better
Daisy

Griffo,
I had a similar problem.
One end of my patch is at the bottom of a slope that rises gently for almost half a mile.
I had problems growing anything there because, after even a short period of rain, the ground got waterlogged.

My solution was to build raised beds.
I constructed beds, each 8'x4' and 1' high, from decking boards, with narrow paths in between.
I filled the beds with a mixture of compost (60%) and topsoil (40%).
I grew excellent crops of onions, shallots, beetroot and turnips.
Now, in the second year, I have had similar good results with the same crops rotated.

I know that the raised beds are the solution to what would have been an ongoing water-logging problem because an adjacent area of lawn, also at the bottom of the same slope, still suffers from the water run-off and becomes boggy.
The paths between the beds still get very wet after prolonged rainfall, but the beds sit above the water level so do not suffer.
Obviously, during the lengthy dry spell that we had (which now seems to have been 100 years ago to us in the NW) watering was necessary, but that is to be expected.
 

We have raised beds on thick clay; and don't water it at all apart from when the seedlings first go in. We mulch with sawdust profusely [it's free] and this eventually gets drawn in after the crop is harvested and helps to aerate the soil.

We did water my onions this year, after the really hot period as we had moved them due to aminopyralid; which was removed by DOW and thus we haven't even got manure to add in now.

We only really dig to get rid of weeds, and the clay below is really good at holding the moisture.

For beetroot, we sow into modules, plant into the clay and mulch. We get huge beetroots this way.

For carrots, we add a good amount of sand and fork it down, sow direct, mulch with sawdust and only weed twice [once when about 4 inches tall and once if any weeds really start to push the nets up].

We also mulch with coffee grounds if we can get any, and usually put them with onions as I find it spurs them on.

I don't have raised beds, but my neighbour does, and you are correct, he waters his more often that we do.  Its because of the water table.  Because his are raised, when it rains it goes through the raised bed to the, for a better word, but not quite true, the bedrock.  When he digs his soil its mostly dry.  But when I dig mine, its damp at approximately 6" beneath the top.  But as most of you know, raised beds for some it works, for others its definitely needed because of the type of soil you have.

I don't know whether my raised beds are raised, or not  :blink: Soil here is heavy clay.

I dug the paths out and put the soil on the beds.  The level of the beds is only very slightly raised, compared to before, but they are never walked on and do have the characteristics of raised beds.

I water pretty much everything once a week (has been twice this year as we have had less than 2" of rain in the last 3 months) - but I think I would do that anyway - an average year for us is only 1" - 2" of rain a month

Getting the humus up must reduce the need for watering? as would a good mulch?

My beds are in their third year (from what was an area of rough grass) and the vigour of the plants is like night and day compared to the first year, and I can't claim that they are well fed / pampered - even the manure they have had is only an inch or so mulch in the Autumn, so not really "lashings and lashings" - the soil structure is greatly improved, probably as much from been "loose" and not compacted for three years.

I have been thinking about whether I would use weed control fabric (or cardboard or something else) for some crops - to provide some drought prevention.  For example, I grow the same number of Sweet Peas plants each year, could easily reuse the same weed-membrane from year-to-year (if I labelled it "Sweet Peas" when I took it up in the Autumn - that would require an interesting improvement in my organisational skills!) Maybe Cardboard would be better