Suitable soil for growing garlic

Last year was my 'if it doesn't work this year I'm giving up growing garlic' year. I had tried lots of times in the veggie bed, with limited success. This time I grew in pots, one to a pot the size that roses or soft fruit bushes come in, four to a larger patio planter. I'm too mean to buy that much fresh potting compost so I filled them with the remains of my tomato planters, which were originally 50/50 horse manure and fresh bought general purpose compost. By the time this was shaken out it was pretty loose.

I had the best garlic I've ever grown (not that that's saying much!) but it was easily the size of supermarket heads.  There was no noticeable difference between the pots (or where there was, it was down to the variety and not the pot size).

I also tried growing some in shallower but wider pots, this didn't work nearly so well.

Not really a scientific experiment but if I were you I'd be going the raised bed/compost route for sure.

Garlic likes light, well-drained soils with plenty of organic matter in it so your plan should work fine.

Don't know why your previous attempt wasn't that successful, but free draining soils can be a bit short of nutrients. 

Have no idea what ex flower stall compost has in it, but don't go too mad with any additional fertiliser, especially nitrogen which can produce soft growth which is more vulnerable to winds and rust damage.

I grow mine is a south facing-raised bed that has a mix of topsoil, lots compost and lots of well rotted manure, there may be a bit of sand in there as well. The mixture is really friable and the garlic does well in it. Other than planting out in October and weeding it in the Spring,  I leave it alone. I don't "feed" it anything but water and it seems to do fine living off of whatever nutrients have been dug into the soil in the Fall.

I don't think garlic is that fussy really. Last year mine went into fairly heavy clay which compacted down to concrete over winter and had puddles on top. Despite this, the garlic was going great until it was hit by rust. Still got some decent bulbs, but it was the rust that limited than rather than the soil. I suspect they wouldn't do well on a sandy soil due to lack of nutients and water.

I have to agree.  Like the original post, I live in Scotland and get my bulbs from the Really Garlicky Company (Scottish grown).  It had never occurred to me that I needed to give garlic special treatment and have always grown it as part of my normal rotation in the raised beds in my veg garden.  I always get a good crop, except this year when there was some rust and the bulbs were smaller than before.  I do add some organic matter to the soil before planting but nothing apart from that.