How to grow melons

Learning to grow your own melons. Tips and helpful information.

The melon is a vegetable that belongs to the cucurbitaceous family, and which is known scientifically as Cucumis melo L.

It is an annual herbaceous trailing or creeping plant, if provided with the appropriate staking. It is made up of young rough shoots with thorns that grow out from the leaf axils.

It possesses an abundant root system which branches out and develops rapidly although the plant does not grow adventitious roots.

The stalks tend to climb and branch out and they are covered with hair and nodes where the leaves, thorns and flowers develop.

The leaves grow out from the main stem. This is the point from which the secondary buds are formed, and then in turn, the tertiary shoots where the female fruit bearing flowers are formed.

The leaves are petiolated, palmate, alternate; covered with hairy down and lobe shaped with 3 or 7 lobes. The edges are serrated although not in an overly pronounced way. The flowers are yellow in colour, singular, lobe-shaped axils. They may be male, female or hermaphrodite depending upon appearance, crop and the interaction of temperature and light together with the fertilizer applied.

The male flowers can be seen on the main shoots 10 to 15 days after planting and they appear thereafter throughout the whole growth cycle.

The female flowers appear 10 days after the male flowers. They are somewhat bigger, with an inferior ovary and appear on the second and third generation of shoots.

The fruit is of the pepo type; which means it is simple, fleshy, indehiscent, sincarpic; it grows from an inferior ovary and has a central cavity.

The shape of the fruit varies, it may be round or oval, the rind is green, yellow, orange or white and it might be smooth, rough or stripy.

When the flesh is ripe it is soft, watery, and green and white or orange in colour. The seeds are white or a yellowish cream, they are oval and flat, elongated and regular in shape.

The melon is rather demanding with regard to heat and light. The average temperatures required for growth vary between 18⁰C to 20⁰C.

This plant is not particularly demanding with respect to atmospheric humidity, the optimum humidity from the time of flowering up to fruit ripening being from 60% to 70%, although until flowering begins it can be kept slightly higher.

With regard to soil humidity, the melon plant is somewhat demanding in order that leaf development and fruit ripening take place as required. However, excess humidity will cause problems with germination, and once the plant begins to grow the result will be choked roots, as well as tasteless fruit lacking in sweetness.

The melon adapts to a large range of soil types, however it is advisable to use well drained and well fertilized sandy clay soil with a pH between 5,8 and 7,2.

When sowing melons you can choose between direct sowing and transplanting, although when considering early crops, sowing needs to be carried out in seed beds due to the limitations of soil temperatures during the colder months.

When sowing is carried out in seed beds, transplanting takes place at the six or seven week stage. This is once the first leaf is truly developed; however it would be ideal for two full leaves to be formed and the third or fourth to be showing.

When planting takes place, holes are made and once the seedlings have been set in place, the root ball is covered with soil and the seedlings are watered in order to facilitate the root taking process.

Mulching is carried out in order to increase soil temperature, diminish evaporation, impede weed formation, increase the concentration of CO₂ in the soil and increase fruit quality as the fruit makes direct contact with the soil. This consists in covering the soil with a black polythene sheet.

With early planting and once transplanting has taken place then plastic tunnels can be set in place to increase temperature levels. Another method which is used is the thermal heating blanket, which although increases the temperature in a minor way, does improve ventilation and prevents problems with drip irrigation.

Another method of increasing greenhouse temperatures after planting consists in using strips of plastic or a cover made of perforated transparent film.

Even though climbing plants are the most common it has to be said that due to the workforce required to produce a high quality crop, the plants need to be staked.

With regard to climbing crops, the most habitual spacing can very between 0,75 and 1plants/m². With staked crops spacing increases, the recommendations being 1,5 to 2 plants/m².

Pruning melon plants stimulates branch growth and diminishes the strength of the plant; this foments the growth of female flowers, accelerates maturity and facilitates ventilation and the application of phytosanitary treatments. This is turn increases early growth and favours the control of quality and fruit size.

The recommended watering method is drop irrigation due to the fact that the melon plant is sensitive to waterlogging.

Nowadays pollination is carried out by bees (Apis mellifera), which is the safest and most effective method of correct pollination.

Beehives are placed inside the greenhouse a few days before the female flowers appear and after the first male flowers emerge. This is done in order for them to become acclimatized.

Flowering tends to occur in stages in order to make way for 2 to 3 crops of fruit. The flowers remain open for two or three days, opening in the morning and closing in the evening. They continue like this until, if by the aforementioned time they have not been fertilized, they will no longer be receptive.

In general terms it will take 100 to 120 days from the commencement of plant growth to the beginning of harvesting. This causes fruit setting to vary between 30 to 50 days, depending on the crop and the growth environment.

The fruit must not be harvested until it is fully mature. Harvesting melons begins with cutting by hand. The fruit is deposited at the end of the rows in order that it might be loaded onto carts. The frequency of harvesting varies from two to three times per week during warm weather, or once a week during colder weather.