Melons are most successfully grown in an unheated greenhouse in rich, fertile soil. A liberal application of well-rotted manure or garden compost should be dug into the soil before you transplant your young melon plants. Alternatively you could grow them in growbags or containers as long as the compost is well drained. If you sowed them in mid spring, then they ought to be big enough to transplant by now, just give them plenty of space about 1m apart.
After planting, keep them well watered but they must not sit in wet soil for long periods as this will cause them to rot. Feed with a high nitrogen fertiliser http://www.thompson-morgan.com/sundries1/product/kww2550/1.html to encourage abundant growth. As the growth develops you can train them onto wires or allow them top grow flat, depending on the space available.
Pinch out the growing point on each plant after four true leaves have developed, to encourage laterals to form. When these laterals have 6 leaves, pinch out their growing tips to encourage sub laterals on which the fruit will form.
When the flowers form, choose five female blooms per plant (female flowers have a small bump underneath them). Using a fine paintbrush and the pollen from the male flowers, you can begin to hand pollinate your chosen female blooms. As the fruits begin to set, remove any further flowers and feed with a high potash feed. http://www.thompson-morgan.com/sundries1/product/kww2552/1.html Be extra careful with your watering as the fruits develop. Overwatering as the fruit develops can make the melons watery and tasteless. I know it sounds complicated, but it is well worth the effort.