My first year on the plot I tried about 12 potato varieties, many were absolutely rubbish for me so now I stick to Charlotte. I love King Edwards for taste but found the crop small and often the slugs would get them.
I have also had a lot of tomatoes through the seed circle, I couldn’t keep up with which ones should be outside and which should be in a greenhouse, which I should pinch out and which should be bushes, so had mixed results. I loved growing all the different varieties but probably should have limited to 5 different types.
Caulis like alkaline soil, so it would be worth doing a soil test and amending with lime. They also like good drainage so maybe a raised bed depending on your soil.