When you grow most of your own veg, winter salads tend to have more cabbage in them, carrots, onions, apple, red cabbage, leeks, kale, spinach beet, anything that stores well, and it's often grated. Summer salads with all the baby leaves feel lighter. I know you can buy them out of season but either they have been grown in huge polytunnels and are tasteless (tomatoes are like water in the winter), or they have been flown from thousands of miles away and are quite elderly. When you have grown a cucumber and have stored it for almost a month, and you buy one and it goes off before the week is up, it tends to put you off buying supermarket veg.