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.
Sow watermelon seeds from April to May for indoor cropping or early April to May for transplanting outdoors later on.
Sow melon seed at a depth of 1cm (½") in trays of free-draining, seed sowing compost. Place in a propagator or seal container inside a plastic bag at a temperature of 25C (77F) until germination which takes 5-7 days. Protect the emerging seedlings from direct sunlight to avoid scorching. Once germinated pot on individual seedlings into 7.5cm (3") pots of compost and grow melon plants on until they large enough to be transplanted into growbags. Maintain a temperature of 25c (77F) and keep the compost barely moist to avoid stem rot.
When watermelon plants are well grown, transplant 2 plants per growbag or 1m (39") apart under frost free glass, or into frames or cloches outdoors. When growing watermelons outdoors cover the soil 3-4 weeks before planting with a plastic mulch. Gradually acclimatise them to outdoor conditions over 7-10 days before transplanting into warm, well drained, humus rich soil in full sun, with shelter from winds. Plant in single rows at a distance of 1m (39") apart leaving 2m (6’) between rows. Pull a little soil around each plant to keep it from touching the plastic mulch. Water well after planting until melons are fully established.
Watermelon plants should be allowed to spread flat on the ground. Pinch out the growing point after 5 leaves have formed to encourage lateral shoots to develop. Select 4 vigorous laterals and train these to 6 leaf stage, before pinching out each growing tip. Remove any other laterals. Fruiting sub laterals will then form on each stem.
Water melon plants regularly, particularly as the flowers develop, and provide a liquid feed every 10-14 days. Shade plants from strong direct sunlight. As the flowers develop, select 4 or 5 female flowers on each plant and hand pollinate them by placing a male flower inside each female bloom. Female melon flowers are identified by a swollen part at the base of the bloom. Once fruit has set remove any further flowers to allow the fruits to develop. Harvest watermelons when they produce a hollow sound when tapped.
Seeds and garden supplies will normally be delivered within the time period stated against each product as detailed above. Plants, bulbs, corms, tubers, shrubs, trees, potatoes etc are delivered at the appropriate time for planting and will be stated on the product page or in your order acknowledgement page and email.
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