Anything with flimsy leaves, like lettuce, or watercress, will suffer in wind, which will dehydrate them and dry the soil in the pots out. Pots are OK but you must water them even if it has been raining.
Every weekend is not enough - every day more like! ;D
Also the size of the pot matters, larger ones can naturally hold more water, and the mix of compost used. Clay based composts are best for retaining water.
Erecting a cloche made with horticultural fleece or old net curtains will offer some wind protection, or you can use netting fences if you are growing on a large scale.
Don't recognise the other plants you speak of: arthritis plant and cineriar (sp) so can't help.