How to Grow and Harvest Watermelon
Watermelons have been cultivated for at least two thousand years for their unique edible sweet "berry" with thick skin and division-less fresh. It is believed that watermelons originated in Southern Africa, but seeds have been found at an archaeological dig site dating back to the reign of Pharaoh Tutankhamen.
There are various types and sub types of watermelon for the South African home gardener.
The following options are available
- Seedless: Developed in the 90's for people who don't want to spit out pips. Pips are tiny soft and easily consumed. Tricky germination process requiring seed being kept at a constant temperature (32 deg C) until emergence of seedling. Small sweet fruit
- Picnic: Developed to be the perfect size by a large group - between 7 and 20kg
- Icebox: The miniature of the family designed to be just right for one person or a small family 2 - 6kg
- Yellow/orange: Bred for their unusual orange and yellow flesh
All varieties come in different classifications and, in turn there are a myriad of types to suit everyone's' needs and tastes.
Soil Preparation and feeding for Watermelon
Watermelons grow very fast and produce large numbers of big, water rich fruit in a relatively short period of time so, for the best results it would advisable to ensure that the soil is rich, fertile and well drained. Prepare soil to about 60 - 75cm working 4 - 5dm of compost and some bone meal into the soil. Mulch well with straw or similar to ensure best soil water retention.
Watermelon vines do not require any support as they grow long vines that run along the ground.
Planting times for cucumbers in South Africa
Picnic: Aug - Nov
Seedless: Aug - Nov
Icebox: Aug - Nov
Yellow/orange: Aug - Nov
Please note: Planting times supplied are in a general South African sense and are based on typical South African Highveld conditions. Your particular area of South Africa might vary, for instance if you live in Tzaneen you have summer all year long and can grow summer crops January to December!
Seed Planting and Germination
2 to 4 watermelon seeds should be planted in elevated mounds ('hills') with flattened crests. Space plants 2m by 2m apart. Mulch crests well after seeds sown
Watermelon seeds germinate at between 20 and 35 degrees Celsius. At lower temperatures germination will be poor and delayed or will fail.
Germination takes approximately 3 to 12 days.
Watermelon Plant Spacing
Days to harvest
Picnic: 85 - 90 days
Seedless: 85 - 90 days
Icebox: 75 - 80 days
Yellow/orange: 75 - 80 days
- Days to harvest is based on typical good growing conditions and can sometimes vary depending on climate, state of soil, and in some instances length of day and climate for the area in South Africa where you reside.
- The specific plant might have characteristic/s that fall outside of the typical type norm.
- Days to harvest are counted from germination or seedling transplant date whichever is the latest.
Timing is crucial when harvesting watermelons. They do not get sweeter once they have been picked. Watermelons are ripe when:
- they sound hollow when tapped
- The fruit stem is half dead (green means it is not ripe and completely dead bears the risk of it being overripe
- the top of the watermelon is dark green and there is little contrast between the stripes and the bottom light patch is cream - yellow (white indicates fruit is not ripe)
When ripe cut stem with a sharp knife close to the fruit
Click to view which Watermelon Seeds are available to you now