Watering brassica's

I water mine while they are recovering from being transplanted, and then give them a good soak once a week if the weather is really dry (like this week)  ie a couple of gallons per sqaure metre. I try to avoid getting the leaves wet. As brassicas are grown for leaves I reckon they shouldn't dry out, so might up this watering to twice a week if the weather is baking 

 Others will have advice too -- be interested to see what they do, too 

Puddle them in when you transplant them and give them a little water until the leaves do not wilt in the daytime any more. After that be quite mean with the water so that they have to put roots down. If you water too often the roots will only be shallow and you will need to keep watering the whole Summer.