you tend to find once the school is locked up at the end of term, thats it until September. i too am having the same problem, with deciding what to grow at school, due to time constraints and holidays. Have decided to mainly go for things that dont need much attention on a day-to-day basis, or things that grow quickly.
so far, were growing lettuce, radish, carrots, tomatoes and french beans. would have grown potatoes, but due to only having one bed, that is 1m x 2m, i though they would take over a bit. same with courgettes, the plant would just be too big for the plot
also the main problem is growing enough of each item, so every child can eat some, and also each child will want to plant something too, so that again, is proving a headache. I think we are gonna have one big plot of lettuce, or hundreds of bean plants
Flea