Watermelon or watermelon is a classic summer fruit from the garden , ideal to eat in the hottest periods, it ripens during the summer.
There are several varieties, the best known have juicy red flesh, but there are also yellow ones. It is a plant of the cucurbitaceae family , with a cultivation similar to that of the melon.
The watermelon fruit is generally very large, it can reach 25 kg, but for the family garden there are also varieties with smaller fruit, called ” baby watermelons “, more suitable for the consumption of an average family.
The suitable soil and climate
Ideal climate. The climatic conditions are the same as the melon, the watermelon is native to warm climates, it has a seed that is born above 24 degrees and then grows well if the temperatures are around 30 degrees, for this reason it is a typically summer vegetable and if the the climate is a bit harsh, you have to think about tunnels or mulching with black sheets to better warm the plants. A temperature below 14 degrees can stop its growth, jeopardizing the harvest.
Ground. The soil for growing watermelon must be rich and non-arid, tendentially acidic (ph above 5.5). It is a crop that requires water and nutrients. Like many plants, watermelon too fears stagnation of water which causes root rot, so the soil is prepared with deep digging and enriched by fertilising.
Watermelon is a demanding plant, it is advisable to prepare the soil with manure and compost, watermelon loves a rich basic fertilization. If you want the watermelon to be sweet, take particular care that there is a good presence of potassium in the soil. If this is not the case, enrich it with fertilizer ( ash can also be used ).
How and when to sow watermelon
When to sow and transplant . The sowing of the watermelon must take place in spring, if you do it in a jar to be kept in protected cultivation you can start in March, otherwise, especially if sown in the open field, it is better to do it between April and May to avoid the risk of low temperatures or late frosts . Even the transplant in the garden should not be done before April.
Sixth planting. After digging thoroughly and preparing a well refined seedbed, the watermelon is sown in postarelle, placing three or four seeds each at a depth of 3 cm. We leave two meters between one row and another and no less than one meter between each plant along the row, watermelons are plants that take up a lot of space and ask a lot of the soil. After the seedlings have sprouted, it is essential to thin them out, leaving only two for each post.
Cultivation and irrigation
Mulch . Watermelon benefits a lot from mulching . In addition to labor savings in weeding weeds, mulching warms the soil, it also prevents the fruit from resting on the ground, safeguarding it both from rot and from any parasites.
Prunings . The watermelon plant can be topped by cutting the apical shoot to avoid the development in width and keep the energies of the plant to develop horizontally.
Weeding . If you don’t mulch, you need to keep the weeds under control and periodically hoe the soil around the watermelons to oxygenate it and keep it draining.
Irrigation. It is essential to guarantee water to the watermelons, frequent irrigations are needed in the germination and transplanting phases, with the growth of the plant an increasing quantity of water is needed because the roots do not go particularly deep. On the other hand, it is not irrigated just before harvesting so as not to water down the flavor of the fruit too much.
Fruit ripening. We recommend rotating the watermelons in the last stages of growth every 2 or 3 days, to let all sides get the sun. It is important to do it once to the left and once to the right, otherwise the stalk is twisted and the fruit comes off before the harvest time. Another useful practice is to raise the fruit with a small board so that it does not rest directly on the ground.
Rotation and intercropping. Let’s avoid cultivating watermelons after other cucurbits and possibly also after solanaceae, all very demanding plants which impoverish the soil. Watermelon looks good next to many plants, such as salads, spinach, onions and tomatoes.
Plant diseases and pests
Watermelon can be affected by various diseases, the most dangerous are virosis, then there are some fungal diseases (the same ones that affect melon).
As far as virosis is concerned, it is necessary to prevent by paying attention to the tools used and keeping the aphids under control .
In the fight against aphids, be careful not to use insecticides, especially in the morning when the flowers open: cucurbits have entomophilous pollination, therefore pollinating insects such as bees and bumblebees are needed which could fall victim to insecticides, even those permitted in organic farming such as the pyrethrum. Against aphids it is therefore better to use natural remedies, such as nettle, garlic or soap and water. If you kill the insects that pollinate you risk finding yourself without fruit.
It is not easy to understand when to pick watermelons and knowing how to choose the right time is essential to have a juicy and sugary fruit. A symptom that heralds ripening is the peel which from wrinkled becomes smoother and “waxy”, if you have seen a nice ripe watermelon you will understand what we mean, the shiny patina can be scratched with the nail. Another symptom is the browning of the tendril which is called vine leaf and is in the opposite position to the fruit, if it tends to dry out the watermelon is ready to be harvested. For those with ears, you can beat the watermelon: if it makes a hollow sound when you knock, it’s ready. Another sign of watermelon to harvest is a slight depression around the attachment of the fruit to the plant.
Watermelon in the refrigerator can also be kept for 20-25 days, in a home garden if you want you can make a gradual collection in relation to consumption
Variety of watermelons
Watermelon has been cultivated since ancient times but today horticulturists prefer varieties of American origin because they are smaller in size, we are talking about fruits weighing about 10 kg which are more suitable for home gardens, while Italian watermelons often exceed 20 kg.
The different varieties of watermelon, from red or light flesh up to yellow, even the skin can be light, dark, streaked or not, there are also seedless hybrids.
For a small home garden we recommend the Sugar Baby variety , it is a very sweet watermelon with small fruit, which generally does not weigh more than 5 kg.