Tesco and Morrison's are among UK supermarkets limiting the number of vegetables shoppers can buy, following a poor harvest. Tesco asked customers to limit the number of iceberg lettuces they buy to three, citing the impact on availability of bad weather conditions in Spain. Morrison's then asked customers to limit consumption to three heads of broccoli. Sainsbury's and Lidl also said they were working with suppliers to maintain supply. Prices have also risen, with the average market price for lettuce up almost 54% in the week of the bans, according to the Department for Environment, Food and Rural Affairs. The Telegraph reported signs of a nascent black market for vegetables.