Watermelon

Looking after it

Water: They need normal watering. While the vines grow and the fruit swells, water deeply and regularly. Water the ground, in the morning. Once the fruit is close to full size, water less. Feeding: Average feeding is enough. Work compost into the soil before planting. Too much nitrogen gives you leaves instead of fruit. If you do feed, use a feed high in potassium once fruits form.

Harvest and keeping

Look for three signs that it's ripe. The curly tendril nearest the fruit is brown and dry. The patch where it lies on the ground turns from white to creamy yellow. The skin turns from shiny to dull. When you see all three, cut it off with a knife. A whole watermelon keeps 2 to 3 weeks somewhere cool, at 10 to 15 °C. Keep it away from apples, bananas and tomatoes. Once it's cut, cover it and keep it in the fridge.

What can go wrong

• Picked too early. A watermelon cut too early stays pale and bland, because it won't ripen off the plant. Wait until you see the dry tendril, the yellow patch underneath and the dull skin together.
• Powdery mildew. The leaves get a white powder, worse when the plants go dry. Water the ground steadily and keep the leaves dry.
• Slugs and snails. They eat young plants. Protect them once they are planted out, especially in damp weather.