How to Grow Watermelon: 7 Tips for a Sweet Harvest

Craving sweet, homegrown watermelon this summer? Growing your own watermelon is incredibly rewarding. With enough space, warmth, and time, you can enjoy juicy melons right from your garden. Learn how to grow watermelon, and you’ll enjoy juicy, homegrown watermelon all summer!

Article Index

1. Select the Best Variety for Your Climate
2. Prepare the Perfect Planting Spot
3. Plant Watermelon Seeds Directly in Warm Soil
4. Ensure Blossoms are Pollinated
5. Provide Optimal Conditions for Large, Sweet Fruit
6. Protect Watermelon from Pests
7. Harvest Watermelon at the Perfect Time

7 Tips for How to Grow Watermelon

Watermelon needs plenty of space and at least 80 days of warm temperatures to grow well. If you can provide these conditions, learn how to grow watermelon with these tips.

1. Select the Best Variety for Your Climate

Most varieties do well in warm climates. Some favorites include Crimson Sweet and Moon and Stars. Try this storage watermelon, Diné Origin Sweet Storage Watermelon, which will keep for months.

In hot summer climates like the low desert of Arizona, choose short-season varieties or types adapted to the heat of the summer, such as Pueblo Watermelon, Desert King, and Hopi Yellow.

In cooler climates, choose short-season varieties such as Sweet Siberian Watermelon, Sugar Baby, or Jeremiah the Bullfrog Watermelon.

Smaller growing space? Choose shorter-vining varieties such as Bush Sugar Baby or Cal Sweet Bush. 

2. Prepare the Perfect Planting Spot

Choose a site for planting that receives plentiful sunlight (at least 6-8 hours). They prefer well-draining soil that’s slightly acidic to neutral. Think sandy loam or loamy soil. Mix in some compost or aged manure. Boost the soil further with a balanced organic fertilizer. Check your soil’s pH and nutrient levels if you’re not sure.

Watermelons need plenty of room to spread. Vines can grow up to 20 feet (6 m) long, so ensure your garden has enough space.

Grow two watermelon plants in one 4 x 8 foot (1.2 x 2.4 m) bed or one plant in a 4 x 4 (1.2 x 1.2 m) foot bed. If you’re tight on space, you might want to try shorter-vining varieties or even grow them in containers or vertically. Growing vertically? Use melon cradles to support the fruit.

If using square foot gardening, plant shorter bush varieties, plant at the end or corner of a bed, and plan on one plant per 3-4 squares. 

3. Plant Watermelon Seeds Directly in Warm Soil

Watermelons do best when sown directly into warm soil (70°F/21°C) or higher. (Use a soil thermometer to check the temperature.) Plant 2-3 weeks after the last frost date. In the low desert of Arizona, March is the best time to plant.

Sow seeds about 1 inch (2.5 cm) deep and 4-5 feet (1.2-1.5 m) apart. Thin to the strongest seedling once they emerge. If you’re in a cooler climate, start seeds indoors about 4-6 weeks before the last frost. Handle the young plants gently, keep the soil moist, and avoid disturbing the roots when you transplant.

4. Ensure Blossoms are Pollinated

Watermelon plants need pollination from male to female flowers. If you don’t have enough natural pollinators, you might need to hand-pollinate. Planting flowers at the ends of your beds can help attract bees and other pollinators.

5. Provide Optimal Conditions for Large, Sweet Fruit

Watermelons really live up to their name—they need a lot of water! Keep the soil consistently moist, especially when the plants are setting fruit. Water deeply and let the top couple of inches dry out between waterings. If possilbe, avoid watering the last week before harvest to prevent bland fruit and split melons.

Start with rich soil, and once the plants begin flowering, switch to a flowering fertilzer. Too much nitrogen will lead to lots of leaves but fewer fruits. Mulch around your plants to keep the soil moist and weed-free.

Let the vines grow naturally and avoid pruning, as the leaves help sweeten the fruit. For bigger and more flavorful melons, limit the fruit to 1-2 per plant. As the season winds down and frost approaches, remove smaller fruits to let the larger ones fully mature.

6. Protect Watermelon from Pests

Keep fruit off the ground with cardboard or melon cradles to protect them from pests like beetles and pill bugs. Check leaves for squash bugs and their eggs. Mesh bags and traps can help with rats. For powdery mildew, remove affected leaves and spray with a mix of potassium bicarbonate powder and liquid castile soap. Learn more in this blog post.

7. Harvest Watermelon at the Perfect Time

Watermelons won’t ripen further once picked, so wait until they’re fully ripe. Cut the stem just above the melon to harvest. Knowing when to harvest is key. Look for these signs:

• The underside of the watermelon turns creamy yellow.
• The tendril at the stem end turns brown.
• The rind changes from a slick sheen to a dull appearance.
• A deep, low-pitched thump when tapped.

For the best flavor, store whole watermelons at room temperature and eat them within a week or two. They’ll last a bit longer in the fridge, but the taste and texture might not be as great. Juice any extra watermelon and freeze it.

Remember to give watermelons space, warmth, and time; you’ll be rewarded with a sweet, juicy harvest. Do you have questions or tips of your own? Drop a comment below.

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