I grew Salanova last year and followed Curtis Stones methods. My issue was that everyone else had salad mix and in Summer I only got 2 cuts. The seed is so expensive plus all the work prepping beds, starting plugs, burning holes in fabric, reconfiguring irrigation, trying to keep them cool, cutting, washing, bagging, weighing, selling about half of it every week
. That said every place is different. I am using Landrace and wild lettuces this year. Head lettuce can easily be a mix. If I was going to get serious about salad mix I'd have to have a greens bubbler, a big spinner, and a walk in like Curtis. Otherwise labor eats into the profit too much for me. I also thought Salanova sucked. Taste and texture like cardboard. Could have been my fault though. I'll add that greenhouse cukes are by far my easiest and most profitable crop.