How to Grow Watermelon from Seed




Growing your own watermelons can be a fun and rewarding gardening project. Whether you have a big backyard or just a small space, you can enjoy the taste of fresh, juicy watermelons right from your garden.

In this blog post, we’ll walk you through everything you need to know about growing watermelons from seed. From selecting the right seeds to caring for your plants, and finally harvesting your watermelons, we’ve got you covered.

We will also tackle some common problems you might face along the way. So, grab your gardening tools, and let’s start the journey to grow your own delicious watermelons!

How to grow watermelon from seed

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Why Grow Watermelons from Seed?

Growing watermelons from seed has several benefits that make it a great choice for gardeners of all levels. First, it’s cost-effective. Seeds are much cheaper than buying plants that are already started. You can save money and grow several plants for the price of one pre-grown melon plant.

You also get more variety choices. When you grow from seeds, you can choose from a wide range of watermelon types that might not be available at your local garden center. This includes rare or heirloom varieties that have unique flavors and colors not found in store-bought melons.

It’s an educational experience. Growing watermelons from seeds can be a fantastic way to learn about the life cycle of plants. It’s especially great for young gardeners who are curious about how things grow.

There’s a deep satisfaction in watching your watermelons grow from a tiny seed into a large, fruit-bearing plant. It feels rewarding to know that the delicious watermelons you end up eating are the result of your own effort and care.

Lastly, when you start from seeds, you have complete control over the growing conditions. This is ideal if you prefer organic gardening because you can ensure no harmful chemicals are used throughout the growing process.

Choosing the Right Watermelon Seeds

Choosing the right seeds is crucial for growing healthy and tasty watermelons. Here are a few tips to help you select the best seeds for your garden:

Heirloom vs. Hybrid:

Heirloom seeds are passed down through generations and often offer more unique flavors and textures. They are open-pollinated, which means you can save the seeds from your harvest to plant next year.

Hybrid seeds are created by crossing two different types of watermelons to produce a plant that has the best traits of both. They tend to be more disease-resistant and can provide more consistent and higher yields. However, seeds from a hybrid watermelon might not produce plants true to the parent type.

Seed Quality:

Look for seeds from reputable sources to ensure they are high-quality and disease-free. You can buy seeds online, at local garden centers, or through seed catalogs.

Also Read:  How To Grow Watermelon Vertically

Check the seed packet for information about the variety’s growth time, size, and climate suitability. This will help you choose a variety that will thrive in your specific garden conditions.

Germination Rate:

Consider the germination rate, which tells you what percentage of seeds are expected to sprout. Higher germination rates indicate better quality seeds.

By carefully selecting your watermelon seeds, you can improve your chances of growing a successful and fruitful watermelon garden.

Preparing to Plant

Preparing the soil and selecting the right time to plant are key steps to ensure your watermelon seeds grow well. Here’s how to get started:

Best Time to Plant:

Watermelon seeds should be planted when the soil has warmed up in the spring. This is usually when daytime temperatures consistently reach about 70°F (21°C) and all danger of frost has passed. In most regions, this is late spring or early summer.

Soil Preparation:

Soil Type: Watermelons prefer loamy, well-draining soil. They need a lot of nutrients and a pH between 6.0 and 6.8.

Amending Soil: Add organic matter like compost or well-rotted manure to your garden bed to improve nutrient content and drainage. If your soil is very clayey or sandy, adjust it by adding organic material and sand or perlite, respectively.

Testing Soil: It’s a good idea to test your soil’s pH and adjust it if necessary. You can buy a soil test kit from a garden center or online.

Choosing a Planting Location:

Sunlight: Choose a spot that gets full sun, meaning at least six to eight hours of direct sunlight each day. Watermelons need plenty of sun to grow big and sweet.

Space: Make sure there’s enough room for the vines to spread out. Watermelons can sprawl over a large area, so plan for at least 20 square feet per plant.

By taking the time to properly prepare your planting area, you’ll create the ideal environment for your watermelon seeds to sprout and grow into healthy, fruit-bearing plants.

Planting the Seeds

Proper planting is essential for germinating watermelon seeds and setting the stage for a healthy crop. Follow these steps to plant your seeds effectively:

Planting Depth and Spacing:

Depth: Plant watermelon seeds about 1 inch deep into the soil. This depth helps ensure that the seeds have enough coverage to retain moisture but can still break through the soil easily.

Spacing: Space the seeds about 2 feet apart in rows. The rows should be spaced about 4 to 6 feet apart. This gives each plant enough space to spread out and grow.

Ideal Temperature for Germination:

Watermelon seeds germinate best at soil temperatures between 70°F and 95°F (21°C to 35°C). You can use a soil thermometer to check the temperature of your garden soil.

Watering Requirements:

Initial Watering: After planting, water the seeds thoroughly to ensure the soil is moist. The key is to keep the soil consistently moist but not waterlogged.

Ongoing Watering: Water the area regularly, especially during the germination period and as the plants start to grow. Watermelons have deep roots and benefit from deeper, less frequent waterings that help encourage root growth.

Covering the Seeds:

Consider covering the planted area with black plastic or a floating row cover to keep the soil warm and promote faster germination. This cover can also help protect the seedlings from pests.

By following these planting guidelines, you’ll help your watermelon seeds start off strong, leading to a healthy and productive watermelon vine.

Caring for Watermelon Plants

Proper care is crucial to ensure your watermelon plants thrive and produce delicious fruit. Here’s how to take care of your growing watermelons:

Also Read:  How To Grow Watermelons In Pots


  • How Much and How Often: Watermelon plants need plenty of water, especially when they are setting fruit. Aim to water the plants deeply once a week, providing 1 to 2 inches of water each time. Adjust your watering based on rainfall, more during dry spells and less when it’s wet.
  • Method: Use a soaker hose or drip irrigation to deliver water directly to the base of the plant. This method helps keep the leaves dry and reduces the risk of disease.


  • Types of Fertilizer: Use a balanced fertilizer that has equal parts nitrogen, phosphorus, and potassium (e.g., 10-10-10). You can also use a more phosphorus-rich fertilizer to encourage good root and fruit development.
  • Frequency of Application: Fertilize the plants every three to four weeks. Start fertilizing after the plants have established themselves and have a couple of true leaves. Stop fertilizing once fruits begin to grow.


  • Best Practices: Keep the area around your watermelon plants free from weeds. Weeds compete with your plants for water, nutrients, and light.
  • Method: Hand-pull weeds or use a hoe to gently remove them. Be careful not to disturb the roots of your watermelon plants.

By following these care guidelines, your watermelon plants will be well on their way to producing big, juicy fruits. Proper watering, fertilizing, and weed control are key to your success.

Troubleshooting Common Issues

Growing watermelons can sometimes be challenging due to pests, diseases, and other issues. Here are some common problems you might encounter and how to address them:


  • Common Pests: Aphids, cucumber beetles, and spider mites are common pests that can attack watermelon plants. These pests can damage the plants and spread diseases.
  • Control Methods: Use insecticidal soaps or neem oil for mild infestations. Covering plants with row covers can also prevent pests from reaching them. Always remove and destroy any infested plant parts to prevent the spread of pests.


  • Common Diseases: Powdery mildew and fusarium wilt are two diseases that often affect watermelon plants.
    • Powdery Mildew: This appears as a white or gray powdery mold on the leaves. It thrives in humid conditions.
    • Fusarium Wilt: This disease causes leaves to turn yellow and wilt, often starting at the base of the plant.
  • Prevention and Treatment: Keep the plants well-spaced to improve air circulation and reduce humidity. Remove and destroy affected plant parts immediately. Use fungicides if necessary, following the directions on the product label.

Insufficient Pollination

  • Problem: Watermelons need pollinators like bees to transfer pollen from male to female flowers. Without adequate pollination, the fruits may not develop properly.
  • Solution: Attract bees and other pollinators by planting flowers nearby or by hand pollinating the flowers if you notice a lack of bee activity.

Nutrient Deficiencies

  • Signs: Poor growth, yellowing leaves, and small or misshapen fruits can indicate nutrient deficiencies.
  • Correction: Use a balanced fertilizer and ensure your soil has the right pH and nutrient levels. Soil tests can help identify specific nutrient deficiencies.

By being vigilant and responsive to these issues, you can help ensure that your watermelon plants remain healthy and productive throughout the growing season.

Harvesting Your Watermelons

Knowing when and how to harvest your watermelons ensures you enjoy them at their peak flavor. Here are some tips to determine the right time to harvest and the best methods to use:

When to Harvest

  • Sound Test: Give your watermelon a tap; a ripe melon will typically have a deep, hollow sound.
  • Appearance of the Tendril: Look for the small tendril closest to the fruit on the vine. When it turns brown and dries up, it’s a strong indicator that the watermelon is ripe.
  • Color Check: The part of the watermelon that rests on the ground turns from white to a creamy yellow when ripe.
  • Firmness: The rind should be hard and not easily dented by a fingernail.
Also Read:  How To Grow Watermelons In Pots

Harvesting Techniques

  • Cutting the Stem: Use a sharp knife or garden shears to cut the stem close to the fruit. Be careful not to pull the fruit off the vine as this can damage the plant and the fruit.
  • Handling: Handle the watermelon gently to avoid bruising. Watermelons do not continue to ripen significantly after they are harvested, so it’s best to use them within a week of harvesting for optimal freshness and taste.

By following these guidelines, you can pick your watermelons when they are perfectly ripe, ensuring the sweetest and most refreshing taste. Enjoy the fruits of your labor by slicing up your home-grown watermelon for a delicious treat on a warm day.


How Long Does It Take for Watermelon Seeds to Germinate?

Watermelon seeds typically take about 7 to 10 days to germinate under ideal conditions. This can vary depending on the soil temperature, which should be between 70°F and 95°F (21°C to 35°C). Ensuring the soil is consistently moist and using a cover to keep the soil warm can help speed up germination.

How Much Space Do Watermelon Plants Need?

Watermelon plants require a lot of space to spread out as their vines can grow quite lengthy. Each plant should have about 20 square feet of space. This spacing prevents the plants from competing for light, water, and nutrients, which is crucial for their health and fruit production.

Can I Grow Watermelons in Containers?

Yes, you can grow watermelons in containers, especially smaller or bush varieties that don’t spread as widely. Choose a large container that can accommodate the plant’s root system and ensure it has good drainage. Keep in mind that container-grown watermelons may require more frequent watering and feeding compared to those grown in the ground.

What Are the Best Companion Plants for Watermelons?

Good companion plants for watermelons include marigolds, nasturtiums, and oregano, which help repel pests. Other beneficial companions are radishes, which can serve as a trap crop for pests, and legumes like peas or beans, which fix nitrogen in the soil and improve soil fertility.

How Do I Prevent Pests From Damaging My Watermelon Plants?

To prevent pests from damaging watermelon plants, keep your garden clean and free of debris where pests can breed. Use row covers to protect the plants during the early stages of growth. Applying insecticidal soap or neem oil can effectively control mild infestations without harming beneficial insects.

Do Watermelon Plants Need a Lot of Sun?

Watermelon plants require full sun, meaning at least six to eight hours of direct sunlight per day, to grow properly and produce sweet fruits. The ample sunlight helps the plants produce the sugars needed for flavorful watermelons.

When Is the Best Time to Water Watermelon Plants?

The best time to water watermelon plants is early in the morning, which allows the water to soak deeply into the soil and the foliage to dry before evening. This reduces the risk of fungal diseases, which can thrive in cooler, moist conditions. Water deeply and infrequently to encourage strong root growth.


Congratulations on reaching the end of your watermelon-growing journey! By following the steps outlined in this guide, you’ve learned how to choose the right seeds, prepare the soil, plant and care for your watermelon plants, troubleshoot common issues, and finally, harvest your delicious watermelons.

Growing watermelons from seed can be a fun and rewarding experience. Not only do you get to enjoy fresh, juicy fruits right from your garden, but you also gain valuable gardening skills along the way. Remember, each growing season is an opportunity to learn and improve.

We encourage you to try growing different varieties of watermelons and maybe even experiment with other garden fruits. Gardening is a lifelong journey full of discovery and enjoyment. Keep nurturing your green thumb, and enjoy all the tasty rewards that come with it!

Hi, I’m John.

John grew up on a farm where his family raised chickens, goats, rabbits, and grew a huge garden. John has a family of his own and gardens to know where his food comes from. Learn more..