Sow from seed or seedlings after all danger of frost is over. Mound the soil and sow seed or plants into the top of the mounds as they need good drainage during early stages of growth. The survival rate can be low with melons, depending on the weather, so plant a number of seeds or seedlings into each mound and thin later if necessary. The minimum temperature they can take is about 16 C so whilst plants are small they will need to be covered at night with a bucket or large pot.
Melons generally are less tolerant of acidic soils than other vegetables and the pH should be 6 or higher. They need high levels of nutrient in the soil – composted manure or complete organic fertiliser, and good air circulation to assist with control of diseases. Composted poultry manure is recommended for melon crops and should be mixed through the soil before planting. Follow up feeding with liquid fish emulsion or seaweed products seems to be beneficial. All melons have poor fruit set so you need to have them in an area where there are lots of bees (for pollination), and full sun. Allow plants to grow and develop runners and flowers. It is really important to encourage as much plant growth as possible in the early stages, and then to keep them growing when the plants begin to flower, so regular watering and weekly liquid feeding at this time is critical.
Once the plant is producing both male and female flowers and beginning to set fruit, pinch out the ends of the long running shoots so that the plant does not expend all its energy on leaf growth. Watering should be reduced once fruit have set, but take care that the plants don’t dry out otherwise the fruit will not mature. Thin the fruits to a maximum of four fruits per plant when fruits are about 2.5cm (1”) in diameter. Stop any fruit bearing shoots at 2 to 3 leaves beyond the fruit to concentrate the energy of the plant into the fruit. Ensure that fruit is shaded by the leaves as melons are prone to sunscald in hot weather. Spray foliage with bicarbonate of soda solution at the first sign of powdery mildew (1 teaspoon of bicarbonate of soda to 1 litre of water).
Fruit should be ready about 3 months from planting and at this stage it may be wise to remove any small melons which are just developing, so that the plant can direct energy into ripening the maturing fruit.
Rockmelons should be quite fragrant when ripe. With both Rockmelons and Watermelons the blossom end of the melon (the opposite end to where the stem attaches to the plant) will become soft. Both varieties of melons will change colour when ripe and the stem which attaches the melon to the plant will dry out. Watermelons have a tendril attached to the stem opposite to the melon where it joins the main vine, when this tendril dries out the melon should be ripe. Watermelons also have a whitish green patch on the fruit where it is in contact with the ground, when this patch turns pale yellow, the fruit should be ready
Pick ripe melons and then leave for a couple of days at room temperature to increase the flavour. Fruit picked early can be left to ripen in a warm room but may not have the full flavour of fruit which has ripened on the plant.