The watermelon has the botanical name Citrullus lanatus and originally comes from West Africa. Because of the sweet pulp, this type of fruit is popular all over the world as a delicious snack. Due to the hard shell, the large fruits are easy to transport, and melons are often imported from distant countries. Nevertheless, with the right approach, cultivation and breeding are also possible in the local latitudes.
Location & soil
In general, melons place high demands on their location and do not thrive everywhere. Although watermelons belong to the cucurbit family, the plants are much more sensitive to the local cold than native cucumbers and pumpkins. Due to its African origin, the plant is dependent on warm and bright location conditions. If these conditions are not right, the watermelon will not be able to grow healthily and will not produce an abundant harvest. In extreme cases, incorrect site conditions can even lead to the death of the entire plant.
- A warm and sunny location is ideal
- Needs at least 6 hours of sun exposure per day
- A bed in front of a south wall is well suited
- Prefers humus, well drained and sandy soils
- Pay attention to loose and light soil quality
- Loosen extremely heavy and loamy soil with sand
- pH should be between 6 and 7
- Pay attention to a sheltered place
- Avoid cool drafts and strong gusts of wind
- Rearing in a warm greenhouse is ideal
Tip: In order to guarantee the watermelon a sun-drenched location, it is advisable to build a raised bed. This way, it can grow beautifully in a slightly elevated spot with lots of sunlight.
Sowing & planting
The sowing and planting of the exotic plants are quite easy. However, the warmth-loving watermelons do not germinate outdoors in the local latitudes because the temperature values are too low. That is why it is preferable to grow outdoors in protected indoor areas or in greenhouses
- Carry out cultivation from seeds at a minimum of 21 ° C
- Place the cultivation vessel on a window sill that is flooded with light
- Germination time is about 7-14 days
- Let the young plants grow for a total of 3-4 weeks
- After the ice saints, plant out in the already warmed bed
- Enrich the soil with plenty of ripe compost beforehand
- Create a drainage layer of gravel or quartz sand
- Dig a sufficiently large planting hole
- Roots have to fit and not kink
- Requires an area of about 1 to 2 square meters
- Is happy about a supportive climbing aid
- First water only moderately, then increase the water dose
Note: When growing, a slow and careful transition from the room into the blazing sunlight of the garden is crucial. Therefore, plant the sensitive plants out on a cloudy and not too hot day.
Container planting & greenhouse
As an alternative, watermelons can also be grown in a tub. In this way, it is also possible to grow on a balcony or terrace without a garden. However, a sufficiently large container is required for success so that the plant can spread out well. However, potted plants should not stand in the blazing sun all day, otherwise the soil will dry out much too quickly and the harvest will be ruined. Growing watermelons in the greenhouse is ideal, as the temperatures here are pleasantly warm even in spring. In addition, there is no risk of late frost nights, which could lead to the death of the plants.
- Compact growing varieties are ideal
- Select large-sized buckets
- Conventional garden soil is not suitable for keeping in pots
- Use a nutrient-rich plant substrate instead
- Enrich with a part of sand and clay
- Compost-based substrates are also suitable
- A partially shaded location on a balcony or terrace is ideal
- Protect plants from the strong midday heat
- Grow from seeds in the greenhouse at the beginning of spring
- Ensure adequate ventilation to prevent rot
- Open windows and doors for a few hours every day
- Especially during the flowering phase to allow pollination
Watering & fertilizing
Watermelons come from tropical countries and have a large demand for water. The soil must never dry out completely, otherwise damage quickly occurs and the plant dies. That is why Citrullus lanatus has to be watered a lot and often, especially in summer. In addition, the need for water increases when the plant is in the fruiting phase. In addition, watermelons also have a high need for nutrients. Most floors can only meet these requirements to a limited extent. Therefore, it is advisable to fertilize regularly when growing so that the melons can grow splendidly. If the crops do not get enough nutrients, the whole harvest can even fail. However, a waiting period of around four weeks must be observed for young plants after planting so that they can get used to the new location in peace.
- Water extensively daily, preferably in the morning
- Water twice on hot summer days
- Never use cold tap water
- Stale and lukewarm water is better
- Ideally collect rainwater
- Not getting the leaves wet leads to powdery mildew disease
- Avoid waterlogging at all costs
- Give nitrogenous fertilizers every two weeks
- Organic liquid fertilizer is ideal for vegetables
- Alternatively, organic horse manure is well suited
Tip: Before the fruit starts to develop, it is advisable to fertilize once a week to support Citrullus lanatus with additional nutrients.
Fruits & Growth
Melons grow as annual plants similar to cucumbers and pumpkins, so overwintering is not possible. For this reason, the plants are torn from the ground after harvest and then completely disposed of on the compost heap. Most watermelons develop a red, glowing flesh. However, there are also varieties with yellow, green, orange or white pulp, which are mainly available in specialized fruit and vegetable stores. The high water content of the fruit is very refreshing, especially when enjoyed chilled in summer. Since watermelons have a high demand for water, the soil is constantly moist. In order to avoid rotting fruits, it is therefore advisable to place sheets made of styrofoam or similar materials under the melons. In this way, direct contact with the permanently damp earth and the resulting rottenness can be avoided.
- Plants form thin and angular shoot axes
- Long growth habit with many branched tendrils
- In extreme cases, they can grow up to 10 m
- Form pinnate leaves that are hairy on both sides
- From June light yellow flowers develop
- Then round fruits emerge, sometimes rather elongated
- Fruits consist of 95% water
- Contain a lot of vitamins A and C.
- Melons continue to gain weight
- Can be up to 50 cm thick and weigh up to 20 kg
- Sag down and lie on the floor
- Shell is a hard shell up to 4 cm thick
Harvest time
Compared to other types of fruit, watermelons take a long time to ripen. Melons must ripen sufficiently so that the large fruits taste delicious and juicy. Only over time does the usual sweet taste develop. In order to determine the degree of ripeness of a watermelon, there are certain signs to look out for. This includes a dark green shell with yellowish spots. When you knock on the shell, you hear a dull sound, and the leaves begin to wither. In autumn, the parts of the watermelon plant turn brown before the first frost and then die. This is usually a sign that the fruit is fully ripe. For this reason, from a botanical point of view, Citrullus lanatus should actually be considered a vegetable and not as a Fruits are viewed as all outer parts of the plant with the time of the ripening fruit die.
- Harvest possible from the end of August to autumn
- Size is not a guaranteed indicator of ripe fruit
- The contact point of the armor changes color from white to yellow
- Check the maturity level by waiting on the phone
- Separate the fruit from the plant with a sharp knife
- Leave the stalks in place, this will keep the shell closed longer
- As a result, the melon has a longer shelf life for consumption
- Store at room temperature, but not in the sun
- Uncut fruits can be stored for up to 2 weeks
- Keep in the refrigerator after cutting
Diseases & pests
In general, Citrullus lanatus is a robust plant that grows healthy and splendid if the site conditions and care measures are correct. However, diseases and pests can occur if these factors are in imbalance. The causes are often compacted soil, persistent waterlogging and frequent water shortages. In addition, too high a salt content in the earth can weaken the immune system of the plants. Especially in the greenhouse, fungi sometimes penetrate the plant via the roots or the root neck and lead to premature death. It is therefore advisable to grow resistant and extremely resistant varieties. In addition, the crop rotation must be observed. Melons may not be grown where other cucurbits grew in the previous year. In addition, young melon plants are a delicacy for voracious nudibranchs.
- Fusarium wilt and red spider appear in the greenhouse
- Examine the plant regularly to prevent spreading infestation
- Always make sure there is sufficient humidity
- Beneficial insects are suitable for fighting
- These include predatory mite Phytoseiulus persimilis and predatory bugs
- Also use larvae of parasitic wasps, lacewings and hoverflies
- Susceptible to aphids, downy mildew and powdery mildew
- Take protective measures against snail infestation
- Scatter chopped straw around the plants
- Lay out slug pellets in the bed
