Hi J - as above note, season ends by October and will really be over by mid November.
For guide of UK seasonality, look at :
http://www.eattheseasons.co.uk/index.htm
Easy to read vegetable seasons chart at the Foody as well:
http://www.thefoody.com/basic/vegseason.html
Hope this helps - and shop local by the way! - use the local farmers' market / farm shop and boycott the s/market imported stuff whenever you can - Spanish strawberries in January or Peruvian asparagus....??
Save the foodmiles, hug a tree, eat the seasons, cuddle a carrot....you get the picture..