"Lark" is one of the best varieties of Sweetcorn, so sweet and tender. It is a midseason variety. "Swift" is the earlier twin variety, and also very good.
However, take care over germination of these thin skinned varieties to prevent rot.
I now germinate the seeds, just covered by vermiculite, in individual cells and grow them on, to plant out after all danger of frost has passed. I get good crops, even this far north in Glasgow.