Watermelon 'Blacktail Mountain' was developed in Idaho to be cold tolerant during summer nights, but also does well under warmer conditions. The fruits, each weighing up to 5kgs (11lbs), have dark green skins with juicy, crunchy scarlet flesh. They can be harvested from midsummer onwards. Height and spread: 4m (13').Melons require high temperatures and humidity. In all but the very warmest areas cultivation is most successful in a greenhouse, or under cover of a cold frame or cloche when growing melons in the UK.