New potatoes to harvest for Christmas?

I thought they had to be grown in containers in a green house or polytunnel TD. Realistic you start your veg growing in spring to harvest in summer and autumn. Our local school had a gardening club and Bulba was involved with helping the children, one year they did try veg. but the majority of it was ready for eating when they were on holiday.

Indeed I did. I have difficulty in seeing the value of schools using veg. as a medium for educating children about growing. Yes, food production is a most important topic but, as Mg says above, the children do lots of work and study during the spring term and then go away when most of the produce is ready to harvest - bummer!
Maybe you could try some salad crops for early harvest, Jenny, and a few later root crops like main-crop potatoes and beetroot to harvest in September - the trouble with this is that some of the children who did the work will have moved on to secondary school and will not see the benefit.
My personal feeling is that more benefit could possibly be gained by growing annual plants in the raised bed so that the children can see the seeds, seedlings and flowering plants all in the same year.

Still time to sow lettuce, beetroot, carrots, spring onions, baby leeks, dwarf french beans....anything that takes 10-12 weeks to mature

But the school holidays have just started, Badfish, so no childrens input for several weeks now.

Thanks everyone for your reply's. This is the problem I have that the six weeks holidays get in the way. The bed in question is in a very sheltered spot, so I might just throw caution to the wind and have a go with a few things and hope for the best. It is a secondary school but I don't have the kids helping if I can help it, as I have to maintain the garden when they are in class.

Thanks again

How much sunlight does it get Jenny? You need good light to grow veggies.