Food, Garden

How to grow watermelon plants and fruit: expert guide and tips

how to grow watermelon and how to choose watermelon (1)

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The healthy watermelon provides refreshment on hot summer days. We’ll show you how to grow watermelon plants and fruit in your own garden.

How to grow watermelon: overview

Watermelons ( Citrullus lanatus ) are considered exotic fruits that are mostly imported from distant countries. In fact, the origin of the green-pink fruit is in West Africa, so the lush melon plants feel most comfortable when the warmth is appropriate. From here melons spread to Western Europe via Turkey and Italy. The Spaniards finally brought the water-giving fruits to America. Today melons are grown all over the world.

Notwithstanding their preference for a warm climate, cultivation is also possible in cooler latitudes with the right tips and tricks for how to grow a watermelon.

Appearance and stature

Watermelons are annual, prostrate to climbing plants with thin and furrowed shoot axes. The leaves are stiffly hairy on both sides and deeply lobed. The yellow flowers appear individually in the axils of the leaves. In our latitudes, around three to four fruits are formed per plant.

The fruits are dark green in color, light green striped and hang on the long branches of the plant. They usually appear spherical, more rarely oval. With a bizarre trick you can also pull square watermelons.

The pulp is usually red and 90 percent water. It is very low in calories and tastes juicy and refreshing. In addition, theFruit is low in sugar and interspersed with numerous black seeds. For some years now, when shopping, you have also come across fruit with almost seedless yellow flesh. There are also melon varieties with white or green pulp.

But is the watermelon really a fruit or a vegetable ? In fact, as an annual plant, the cucurbit is assigned to vegetables. Also read: How to grow pineapples from tops or seedlings: step-by-step guide

How to grow watermelon: timing, procedure and location

Although the watermelon is a cucurbitaceae, it is much more sensitive to cold than cucumbers or pumpkins. You should therefore pay attention to a few points when choosing a location and the right time.

Where to grow watermelon: the right location

Melon plants are generally demanding in terms of location. You should therefore pay attention to the following aspects in how to grow watermelons: Watermelons prefer a sandy and humus-rich soil. Soils that are too heavy hinder root penetration and tend to backwater. Also read how to grow broccoli easily: complete guide for garden, pots or sprouts

We also recommend preparing the bed with plenty of compost before planting out so that the watermelon plant gets enough nutrients. In addition to the right soil, a warm, sunny and sheltered place is an advantage for melons. The south wall of the house or the warm climate in the greenhouse, for example, offer ideal conditions.

Dark sheets of plasttic can be laid over the beds three weeks before the plants are planted and the edges dug in on the left and right. The black plastic sheeting ensures that the earth warms up and that the heat can be stored for longer. It also suppresses weed growth and reduces water evaporation

Crop rotation and mixed culture

Good preceding crops for watermelons are cucumbers . As a pre-culture also recommended that a green manure with a high proportion of legumes. Since watermelons need sufficient space to develop the fruits, they should not be grown in the bed with other vegetables.

When choosing a location, pay attention to these aspects:

  • Light and humus soil (too heavy soils are unsuitable)
  • Warm, sunny and sheltered place
  • Ideally in the greenhouse or on a wall that gets sunlight

How to grow watermelon: the correct planting time

Watermelons are plants that have a high need for warmth – planting them out too early can therefore be fatal! Plant young plants outdoors at the earliest from the end of May to the beginning of June, in the greenhouse you can start in April. It should be noted that melons are sensitive to temperatures below 12 °C.

How to grow watermelon: the procedure

The actual planting out of the exotic is relatively easy: Place the young plants in the bed with sufficient distance. Basically calculate 1 to 2 square meters per plant so that it has enough space to grow. Also read how to grow pumpkins: complete step-by-step guide

Pre-grown watermelons can be planted in the bed after about four to five weeks with a distance of 100 x 100 centimeters. Before planting out, it can be helpful to add compost to the soil . A culture with mulch film including a fleece cover or film tunnel is recommended to protect the fruit from rot and moisture.

How to plant watermelon in the pot

A good alternative to growing melons in beds is to plant them out in a pot. In this way you save space in the bed and still don’t have to go without the delicious fruits. When growing watermelon in pots, you should note that the earth warms up faster than outdoors, but also dries out faster. Therefore, choose a saucepan that is as large as possible and water often. It is also an advantage not to place the plant in the blazing sun, because the soil dries out faster there.

How to grow watermelon: buy plants or propagate them yourself?

Before you start growing watermelons in spring, many people ask themselves the question: buy a melon plant or prefer it yourself? We introduce both options and show you the advantages and disadvantages.

How to grow watermelon from seed

Growing your own watermelon plants is quite unproblematic and the germination rate is high, when you follow the steps for how to grow watermelon seeds correctly. To do this, plant one seed per seed pot about 1 to 2 cm deep from March to April. A temperature of over 18 ° C is necessary for germination, ideally this is 22 to 24 ° C. The window sill is a very suitable place for cultivation and the first seedlings can be seen after 5 to 10 days. As soon as the first leaves appear, the young plants can then be pricked out into larger pots. When repotting, be careful not to damage the roots, as watermelons are very sensitive to injuries.

When propagating watermelons, keep these tips in mind:

  • Sow from March to April at a depth of 1 – 2 cm
  • Position on a window sill or in a mini greenhouse (min. 18 ° C)
  • First seedlings appear after 5 – 10 days
  • Prick into larger pots as soon as the first leaves appear

How to grow watermelon: seedling plants

A less time-consuming method than bringing forward seeds is to buy young plants that have already been brought forward. You can buy these from May to June in the garden center and then plant them outdoors in the same way. One advantage of these young plants is that they are often grafted on pumpkin rootstocks and are therefore less prone to root diseases. Basically, the purchase is also a question of cost, as larger quantities of plants grown in advance are much more expensive than seeds.

Watermelon varieties

When talking about watermelon, many people think of the large green fruit with the pink pulp – but the species is actually very diverse. The varieties visually differ greatly from one another, but they are all of the Citrullus lanatus species . There are basically two variations of watermelons:

1. Citrullus lanatus var. Lanatus: This variation includes the cultivated watermelons that are grown commercially around the world. It is the classic watermelon that everyone knows.

2. Citrullus lanatus var. Citroides: This wild form of the melon grows mainly in Africa and is also known as the tsamma melon. The pulp of this variation is not pink, but yellowish to light green.

The varieties for cultivation in this country mainly belong to the variation Citrullus lanatus var. Lanatus . Some of them can also grow in our cooler climates.

We provide some popular watermelons s locations following procedure, you can find a bigger list here.

Bush sugar baby

  • New breed that emerged from Sugar Baby
  • Early ripening with smaller fruits: 2 – 4 kg (1 – 2 fruits per plant)
  • Red flesh with a dark skin
  • Plant remains quite compact (1 square meter per plant)

Crimson Sweet

  • Worldwide popular and popular variety
  • Oval and light green fruits; high fruit weight: 5 – 8 kg
  • Aromatic light red pulp
  • Good resistance to leaf rot and other fungal diseases
  • 1.5 – 2 square meters per plant

Red Star

  • Dark skin and deep red pulp; high sugar content
  • Fruit size: 6 – 8kg
  • The variety is suitable for cultivation in temperate climates and should not be cultivated in rough areas due to the somewhat longer ripening period
  • 1.5 square meters per plant

How to plant watermelon: proper care

As soon as the watermelon plant has got used to its location in the garden, its growth can hardly be stopped. However, there are a few tips you should follow so that the plant is adequately supplied with water and nutrients.

Properly water watermelons

Watermelons have a high water requirement – not surprising when you look at the juicy flesh. It is therefore particularly important in summer to water the plants sufficiently. The soil should be watered daily, especially every morning, especially during fruiting. Be sure to use only tempered water, as the plant does not tolerate water that is too cold. You can use water from the rain barrel, for example. When watering, make sure not to wet the leaves, as this increases the risk of infection with powdery mildew.

Fertilize watermelons

Watermelons are considered to be heavy consumers in the garden – a good supply of nutrients is therefore particularly important. Before planting out, it is advisable to first incorporate a primarily organic organic fertilizer such as our Plantura organic tomato fertilizer or compost into the bed. In the further course of the summer, fertilization is carried out again.

Diseases and pests to beware of

Like other melons , the watermelon is susceptible to powdery mildew and downy mildew, although it is generally more robust than other types of melon. Spots on the leaves indicate angular leaf spot disease or the watermelon mosaic virus. It is important to destroy infected plants and to keep the crop rotation.

Fusarium fruit rot can also occur if the weather is too humid and the distances between the plants are too narrow. It is expressed by yellow-brown spots on the skin. The red spider and the whitefly should be mentioned as pests.

How long does it take to grow watermelon to ripeness?

Knowing how long to grow watermelon is crucial, as you do not want to pick them too early. The ripening time of watermelons is comparatively long – the large fruits are only harvested from the end of August until autumn.

The fruits ripen around 40 to 45 days after fertilization. There are several signs of a ripe watermelon: On the one hand, watermelons sound slightly dull and hollow when you knock on the peel. Another sign of ripeness is when the tendril opposite the fruit begins to wither. In addition, the fruits turn slightly yellow where they lie. But be careful: the watermelons shouldn’t be overripe either, because then they taste very watery and stale. To harvest, you should cut off the stem of the fruit with a sharp knife.

For the taste it is essential to only harvest ripe fruits because they only develop their sweet taste over time. To tell if a watermelon is ripe, look out for these signs:

  • Dark green skin with yellowish spots
  • Dull sound when knocking
  • Wilting autumn leaves
  • ripe watermelons
  • Yellow discoloration on the skin is a sure sign of maturity

How to store watermelons

The shelf life of watermelons is relatively limited and, ideally, they should be consumed quickly. The exotic fruit can be stored uncut for two weeks at room temperature without any problems. As soon as it is cut, the shelf life is unfortunately shortened very quickly and should therefore be stored in the refrigerator.

Freezing watermelons, on the other hand, is not recommended as the fruit consists largely of water and becomes mushy after thawing. You can find out more about harvesting and storing watermelon correctly here.