Growing Melons

  Melons need a minimum of 80 hot summer days. If you live in an area where summers are shorter, consider growing them in a greenhouse.

Credit: Elizabeth Rowlands

Melons need a minimum of 80 hot summer days. If you live in an area where summers are shorter, consider growing them in a greenhouse.

Most garden centres offer starter melon plants or seed for sale. The trick with melons is to set out the largest seedlings possible and to wait until the soil has completely warmed up. In most areas this will be the first week of June; ideally the outdoor daily air temperature will be above 19ºC (66ºF). Start seeds indoors or in a greenhouse six weeks before the date of your last frost, usually around mid to late April. Be sure to use only sterilized soil and maintain a soil temperature of 22ºC (72ºF).

Transplant healthy seedlings into a 10-cm (4-in.) pot after the second set of leaves has developed. Compost any seedlings that are weak or yellow. A week before planting the seedlings outdoors, cover the garden bed with a row cover or black plastic to help increase the soil temperature. It’s also a good idea to use a row cover or cloches over the seedlings for the first two weeks. Pick the sunniest, warmest area of your garden to plant melons. Add extra compost, leaf mould, and 1⁄4 cup (50 mL) each of lime and bone meal to the planting hole. The extra organic matter will help to ensure the soil stays moist and the lime will sweeten the soil, allowing the melon to absorb nutrients. The bone meal will provide extra calcium, necessary for fruit development. The first four or so flowers on a melon vine will be male and will not develop fruit; the later flowers, identifiable by a distinct swelling below the petal tube, will be female. Melons rely heavily on bees for pollination, so plant some sweet alyssum among your melons to attract them. If the weather is cool or bees are scarce, get out the feather duster and dust the melon flowers, thus transferring pollen from male to female flowers.

It’s important to water the plants daily; if they dry out they will abort their fruit. Fertilize at planting time with a slow-release organic fertilizer suitable for vegetables, and apply a liquid kelp or fish food every 10 days. The fruit will ripen at the end of August or in early September. Three melons commonly grown are cantaloupe and honeydew (Cucumis melo), and watermelon (Citrullus lanatus). Of the three, cantaloupe and honeydew are the easiest to grow and likeliest to produce fruit in our region. All three are sweet, easily digested and loaded with vitamin C and potassium. The fruits will not ripen off the vine. When ripe, cantaloupe and honeydew will easily detach from the vine when light pressure is applied to the stem.

Watermelon needs higher temperatures to set fruit and takes longer to ripen. You’ll know a watermelon is ready to harvest when you tap it and hear a hollow sound. Another indication is when the tendril nearest to the fruit is dry. Watermelons should be cut from the vine, not pulled, as they may tear.


‘Earligold’ cantaloupe: Ready in 75 days, this is an early and reliable cantaloupe. Round, densely netted, 1.4- to 1.8-kg (3- to 4-lb.) fruits have thick, sweet, orange flesh that’s high in beta carotene. Ready to harvest when the skin turns grey to tan. • ‘Charantais’ cantaloupe: Popular in Provence, this melon has highly aromatic orange flesh. It is plump, round and weighs in at less than 1.4 kg (3 lb.). When ripe it has very smooth grey skin. • ‘Early Dew’ honeydew: Ready in 80 days, this sweet green fruit is well-suited to our shorter season. When ripe it weighs 900 g (2 lb.) and develops a golden patina on its white skin. • ‘Diana’ watermelon: Diana is the improved version of Golden Crown – slightly smaller with a darker-pink flesh. Fast to mature, the small golden-yellow fruits weigh about 1 kg (2.2 lbs) for one-meal convenience. Resistant to disease. • ‘Northern Sweet’ watermelon: Ready in 85 days, this is a full-size watermelon. Developed for shorter seasons, the round fruit has a dark-green, striped rind and sweet red-orange flesh.