Growing Cantaloupes

Cantaloupe, or rock melon, as it is called in Sydney, is a trailing vine that loves a long warm growing season. It is a member of the cucurbitaceae family and originates from the area from Iran to India.

Sow seeds in pots from September, October and then plant them out in November and December in Sydney, which has a temperate climate. Alternately, the seeds can be planted directly into the garden beds when the temperature is at least 16ºC.


Growth habits and planting needs

Cantaloupes grow best in fertile, friable, well drained, warm soil that is well enriched with humus, so good soil preparation before planting is essential for a good crop.

Select a site that gets full sun, has good air circulation and has bee atracting plants nearby for later pollination of the canteloupe flowers. Borage, nastursiums and dill are useful companions to have growing near the planting site. Also make sure that there is adequate space for the vine to ramble over of at least 90 -180 cm.

To avoid the build up of pests and diseases, the site should not have been previously planted with other members of the cucurbitaceae family like; squash, pumpkins, zucchini, other melons or gourds, cucumber or luffah. In the crop rotation system cantaloupes should follow leafy vegetables which use some of the nitrogen. Cantaloupes, as fruiting vines, need phosphorus and not too much nitrogen which will encourage leaf growth at the expense of fruit.

Cantaloupes do not like acidic soil and prefer to grow in soil with a pH range of 6.0-6.5, so test the soil and amend it incorporating lime or dolomite if the soil is too acidic, to raise the the pH and so make calcium and magnesium available to the plants. Adding organic matter such as well rotted compost and aged cow manure will lower the pH over time. So, test the soil ahead of planting, about 4 weeks before and amend the soil accordingly, so that the soil conditions and nutrients will be available to the plants when they need them.

Sow the seeds in pots from September, October and then plant out the seedlings in November and December in Sydney, which has a temperate climate. Alternately, the seeds can be planted directly into the beds when the soil temperature is at least 16ºC.

Put a layer of cow manure over the soil then create a hill 5 cm high to plant the seeds into.

Sow the seeds 1.5 cm deep, planting 4-6 seeds on each hill. Space the hills 160 -180 cm apart.

The seedlings will emerge after 3-5 days when the soil is 32º C warm and up to 10 days when the soil is cooler at 21º C.

If sowing in pots, the seedlings should have at least 2-3 true leaves and the roots should fill the entire pot. Plant out after 4 weeks.

True leaves emerging

Whichever way you choose to plant your cantaloupes thin to 3 strongest plants per hill using scissors to carefully clip off the unwanted plants at soil level. This prevents any damage to the delicate roots of the remaining seedlings.

The growing cantaloupe showing the curled tendril.

The Cantaloupe has an extensive shallow root system. In fact, when the vine is 60 cm long the roots have a spread of 90 cm with a 20 cm taproot. It fully occupies the top 15 -20 cm of soil. The roots of the mature plants thoroughly fill many cubic cm of soil to allow the plant to take up nutrients and water to support the vine and fruit development. The mature plant will then occupy 40-60 cm of the soil in all directions.

The following diagrams show the extent of the shallow root system of the cantaloupe.

The root system of a cantaloupe plant after 35 days showing the extensive shallow roots and the tap root. (Grid measurements in feet.) Source: Soil and Health Library.
Surface view shows the spread of  the root system after 14 weeks. (Grid measurement is in feet.) Source Soil and Health Library.

These diagrams highlight the importance of adequate watering needed across the area under the developing vine.

Due to the extensive shallow root system mulch well around the plant, keeping it well clear of the stem of the cantaloupes and extending for some area in all directions. This will conserve water in the soil by preventing evaporation and suppress weeds too.

It is important to make sure that the plants receive consistant water, with light, frequent waterings until flowering and pollination occurs. Use drip irrigation around the plants to stop powdery mildew or water gently under the leaves if hand watering.

Continue to water in this way until the fruit is the size of tennis ball then cut back the watering a little but do not allow the soil to dry out. The sweetness of the fruit is affected by the adequacy of water.

When the flowers of both kinds appear pinch the ends of the vines to conentrate the growth on the developing fruits and cover them with the leaves to protect the skin.

A number of fruits will develop on each vine but remove leaving 3-4 of the best to develop.


The cantaloupe should be ready to harvest in 12 weeks. The stem attaching the cantaloupe will dry out and the fruit will slip off the vine. It should have changed colour to a fawn colour and have a good fragrance. The blossom end will be soft.

For full flavour pick when fully ripe (rather than still to ripen) and then allow the fruit to sit at room temperature for a couple of days before cutting as this will develop the flavour.

Cantaloupes will keep chilled in the refrigerator for about 2 weeks.

Three young cantaloupes.
Moving the leaves away to show a good sized cantaloupe.
A mature cantaloupe.

Cantaloupe is delicious and sweet and in Italian cuisine is eaten with prosciutto as an antipasto.

Antipasto of cantaloupe with prosciutto, nasturtium, rocket and borage flowers.

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