Growing watermelons in pots is a challenging but rewarding endeavor, especially in the UK's northwest region with its unique climate. Here's a comprehensive guide to help you succeed in this endeavor, offering a mix of practical tips and personal insights.
1. Choose the Right Variety
Personally, I think selecting the right watermelon variety is crucial. Watermelons can grow up to 10 feet, so opting for compact and bush varieties is a wise choice. These varieties, such as 'Sugar Baby', 'Bush Sugar Baby', or 'Golden Midget', are more manageable and produce fruit that's just as tasty and juicy as their larger counterparts. The shorter vines, often reaching 2 or 3 feet, make them ideal for containers.
2. Select a Large Pot
In my opinion, using a large pot is essential. Watermelons have extensive root systems, so they need ample space to develop. A pot that's too small can lead to root-bound plants, increased watering needs, and stress. Aim for a 15 to 20-gallon pot, 18 to 24 inches deep and wide, with drainage holes. This size provides the roots with the necessary room to grow and simplifies maintenance.
3. Prepare the Soil
Watermelons are heavy feeders, so using the right soil is vital. Combine a quality potting soil with compost at an 80:20 ratio for a rich, well-draining mix that provides essential nutrients. Organic potting mixes or compost can be purchased, or you can make your own compost at home. This blend ensures the watermelon grows healthily in the container.
4. Planting the Watermelon
You have two options for planting: sowing seeds directly or buying transplants. If sowing seeds, plant two or three seeds an inch deep and keep the soil moist. Once seedlings emerge, thin them to keep the strongest one. If buying transplants, dig a large hole and carefully transplant the seedlings to avoid shock. Watermelon plants can be trained to trail across the ground or up a trellis, making them suitable for smaller spaces.
5. Sunlight and Temperature
Watermelon plants thrive in full sunlight and temperatures over 70°F. Place the container in a spot that receives 8 to 10 hours of sunlight daily. Gardeners in cooler climates may need to grow watermelons in a greenhouse or cold frame to ensure the required temperatures for optimal growth.
6. Watering
Regular and consistent watering is crucial. Watermelons need a lot of water, especially in pots, as the soil can dry out quickly. Keep the soil consistently moist, watering once or twice a day during the season. Check the moisture a few inches under the soil surface daily and water if it feels dry. Deep watering is essential, and you can use a soil moisture meter to ensure you're not overwatering.
7. Fertilization
Watermelons are hungry plants, requiring regular fertilization. If you added compost at planting, it provides initial nutrients. Otherwise, use a balanced, slow-release fertilizer. Once the plant starts flowering, switch to a product higher in phosphorus and potassium to encourage fruit development. Seaweed fertilizer or homemade comfrey fertilizer can be applied every two weeks during the summer.
8. Harvesting
Watermelons take 70-90 days from planting to harvesting. Look for signs that the watermelon is ready, such as a brown curly tendril near the fruit, a hard and matte rind, and a deep, hollow sound when tapped. Cut the melon from the vine with a sharp knife, and enjoy the sweet, juicy fruit.
In conclusion, growing watermelons in pots is a challenging but rewarding endeavor. With the right variety, pot size, soil, and care, you can enjoy a bountiful harvest of sweet, juicy watermelons, even in smaller spaces or cooler climates.
