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How to Plant Watermelon

Nothing says summer like a ripe, juicy watermelon. This tasty fruit is so sweet and refreshing, it’s easy to see why it’s so popular!

Fresh watermelons you grow yourself taste even better. If you’d like to try your hand at growing this summer staple, this guide is for you! I’ll show you everything you need to know to learn how to plant watermelon.

Whether you want to start with plants from a nursery or learn how to grow watermelon from seed, this guide has you covered.

I’ll go over when and how to plant, how much to water, when to fertilize, and give you plenty of tips and tricks for growing the best watermelons.

Closeup of watermelon on the vine. Knowing how to plant watermelon means enjoying the iconic summer fruit.

Different Types of Watermelon

Watermelons come in two main types. Seeded and Seedless. The growing process is pretty much the same for both types and you can grow either one at home.

The main difference is that seeded watermelons don’t need an additional pollinator, meaning you can plant just one seeded variety and it will produce fruit. Seedless watermelons don’t have viable pollen so they need a seeded variety planted nearby in order to produce fruit.

If you’re interested in learning more about the science behind this, check out this article on growing seedless watermelons from the University of Nebraska.

And yes, you can actually buy seeds to plant seedless watermelons! Seedless watermelon seeds are a bit trickier to germinate, but I’ll give you all the tips you need for how to plant seedless watermelon from seeds below.

Growing watermelon in a garden

Watermelon Colors

You can’t go wrong with a classic red watermelon but did you know that watermelon comes in even more colors? Wow your friends and family by growing watermelons in a unique color like yellow or orange.

Yellow and orange watermelons have a tough, green rind similar to red varieties, but the color inside is surprisingly different. Curious about what they taste like? Yellow and orange watermelons taste a lot like red varieties but they’re often sweeter. If you love sweet watermelons give an orange or yellow variety a try!

Varieties of Watermelon to Try

Watermelon Variety

Description

Shop Here

Captivation Seedless

14-17 lbs, includes Sangria as pollinizer

Charleston Gray

30-35 lbs, heirloom variety

Crimson Sweet

20-25 lbs, All American Selection winner

Orangeglo

25-30 lbs, orange flesh with tropical flavor

Sugar Baby

10-12 lbs, heirloom icebox variety

Tailgate Seedless

17-21 lbs, high brix rating, includes pollinizer

Yellow Doll

6-10 lbs, yellow flesh icebox variety

You can find all of these watermelons and other varieties at one of our favorite seed retailers Hoss Tools. We love Hoss because they have a great selection of garden seeds all at reasonable prices.

In addition to seeds, you can find all the tools and equipment you need for starting watermelon seeds and caring for your garden.


The Right Growing Conditions for Watermelon

Providing the right conditions sets your watermelon plants up for success right from the start. Here’s what you need to grow watermelon.

Soil

Watermelons are heavy feeders. They thrive in rich, fertile soil with lots of organic matter. Adding compost when planting is an easy way to get more organic matter into the soil. You can also add aged manure, seaweed, or a slow-release fertilizer.

For best results, the soil pH should be between 6.0 and 6.8 but watermelons can tolerate a lower pH, down to about 5.0. Soil test kits are a quick way to check the pH of your soil before planting.

Sun

Watermelons need full sun to thrive. Make sure to plant watermelons in a sunny location where they’ll receive at least eight hours of direct sunlight per day.

If you don’t have a location that’s sunny enough, all is not lost. Watermelons can tolerate partial shade they just won’t produce as much fruit and the ones you get will be smaller.

A blossom on a watermelon plant with a small fruit in the background.

Temperature

Watermelons are a summer crop. They like hot days and warm soil. Wait to plant watermelon outdoors until at least two weeks after your last frost and the soil has warmed to at least 70 degrees.

To help the soil warm up faster, cover it with black plastic sheeting for a few weeks before planting.

Space and Location

Watermelon vines need a LOT of space to grow. The vines often grow to be 6-8 feet long and the fruits themselves are also large. Provide 3-5 feet between each watermelon plant in your garden.

It’s possible to plant watermelons in a raised bed or a large pot, just know the vines won’t stay contained within the container. They’ll come up and over the edges, so make sure there’s space around your container for the plant to spread out as it grows.

If planting in a container, it needs to be large enough to hold approximately 15-20 gallons of soil.


Starting Watermelon from Seed

Newly sprouted watermelon seedlings.
Newly sprouted watermelon seedlings.

Starting watermelon from seed has a lot of advantages. You have total control over how the plants are grown and it’s a lot cheaper to buy seeds than seedlings.

One of the best things about starting watermelon from seed is that you’re able to choose unique varieties that are hard to find as starter plants in a store.

Starting Watermelon Seeds Indoors

Watermelon plants need several months of hot weather in order to produce. If you live in an area with a short growing season, starting seeds indoors gives your plants time to grow and produce before it gets cold again.

Even if you live in a warmer climate, starting watermelon from seed is a great way to get an earlier harvest and save some money.

Seed Starting Equipment

Having the right tools makes starting watermelon seeds easier and increases your chances of success. With good equipment, you can provide the right conditions for seeds to sprout and help them grow into strong and healthy plants.

Seedling Starting Equipment

Hoss Germination Mat

Indoor Seed Starting Light Kit

SunGrow Black Gold Seed Starting Mix

Potting Mix

48 Cell Seed Starting Kit

Small Containers

Gardening Gloves

Garden Shovel

Spray Bottle

Watering Can

Garden Labels

Why Use Compostable Pots?

Before we get into how to start watermelon indoors it’s important to note that watermelons don’t like to be transplanted. Moving a watermelon seedling from one container to another disturbs the roots and stresses the plant. When watermelon plants are stressed it slows down their growth considerably so we want to try to avoid it.

For this reason, it’s best to use compostable pots that can be planted directly into the garden. That way, you don’t have to take watermelon plants out of their container and risk disturbing the roots. Just plant the whole thing in the ground!

How to Start Watermelon Seeds Indoors

Fill your pots with seed starting mix. Poke a hole in the mix and plant 1-2 seeds per pot. Cover the seeds about 1/2 an inch deep and water thoroughly.

Place the pots on a drip tray and put the whole thing on a heat mat to warm up the seed starting mix. Cover the tray with a humidity dome to trap the heat and keep everything nice and moist.

Depending on the variety you’re growing, seeds will emerge in about 4-12 days. About a week after they emerge, thin the seedlings to one plant per pot.

A starter tray of watermelon seedlings.

For more information on caring for seedlings after they sprout, check out How to Care for Seedlings.

Tips for Starting Seedless Watermelon Seeds

Seedless watermelon seeds are a bit trickier to start than seeded watermelon varieties. Here are some tips to ensure success.

  • Use a light and fluffy seed starting mix like Sungro Black Gold
  • Use a heating pad to make sure the seed starting mix is very warm
  • Keep the mix moist (but not soggy) at all times
  • Start extra seeds in case some don’t germinate

Direct Sowing Watermelon Seeds

Watermelon loves hot weather. If you live in an area where you’ll get at least three months of warm temperatures, it’s possible to plant watermelon seeds directly into the garden. With direct sowing, you don’t have to worry about transplant shock!

How to Plant Watermelon Seeds Outside

Two watermelon seedlings planted in a soil mound.

Wait until a few weeks after all danger of frost has passed and the soil temperature has reached 70 degrees to plant watermelon outdoors.

Mound the soil into hills that are about one foot tall and 3-5 feet apart. Poke 4-6 holes in the top of each hill and plant one seed per hole. Cover the seeds with soil 1/2 inch deep and water thoroughly using a watering can or a hose with a watering attachment.

Keep the soil moist while seeds are germinating. After about two weeks, thin the baby watermelon plants to 2-3 per hill.


How to Plant Watermelon Seedlings

As I mentioned earlier, watermelons don’t like to be transplanted so this process needs to be done carefully!

If you started watermelon seeds indoors, make sure to harden off the plants before transplanting.

Planting Watermelon Seedlings

A young watermelon plant.

Create hills in the soil that are about a foot tall and at least three feet apart.

If you have compostable pots, very gently remove the bottom of the pot, then plant the pot at the top of the soil hill. Water thoroughly.

If you bought watermelon seedlings from a store, chances are they’re in plastic containers. Very carefully remove the plant from the container and try not to disturb the roots.

Plant one seedling at the top of each soil hill and water thoroughly.


Caring for Watermelon Plants

Learning how to plant watermelon is just the beginning. Providing the right care is also important for getting a good harvest.

Water

Watermelons need the most water when the plants first start growing. Water regularly with 1-2 inches of water per week as the vines start growing and flowering. Once the fruit starts setting, reduce watering to once every 10 days or so.

It’s important to give watermelons enough water while they’re growing (they’re called WATERmelons, after all!) But it is possible to overwater. Too much water can lead to a bland flavor or cause watermelons to burst.

A drip irrigation line providing water to a watermelon plant.

Mulch

Adding mulch after planting watermelon has several benefits. It prevents evaporation to keep the soil nice and moist, cuts down on weeds, and adds nutrients back to the soil.

Mulching around watermelon plants also helps keep ripening fruit off the soil. Direct contact with the soil increases the likelihood of rot and makes it easier for pests to get to your watermelons.

Use natural mulch like composted woodchips, grass clippings, or straw. If you use grass clippings make sure there are no weed seeds.

Weeding

Weeds compete with watermelons and take valuable nutrients out of the soil. Tackle weeds early, and don’t give them a chance to grow around your plants.

Fertilizer

Person holding handful of granular fertilizer mix.

Since watermelons are heavy feeders, they benefit from regular applications of fertilizer. Use a balanced, slow-release fertilizer like Scott’s once every few weeks.

Tips for Getting Sweet Watermelons

Watermelons have the best flavor when they have the best growing conditions. For sweet watermelons, make sure your plants are happy and not stressed.

  • Provide regular, even water
  • Stop watering a week or two before harvesting
  • Protect the plants from pests and disease
  • Plant in rich, fertile soil
  • Give them plenty of nutrients

Ways to Use Watermelon

Watermelon and kiwi popsicles.
Watermelon and kiwi popsicles.

Plain watermelon slices are absolutely delicious. It’s one of the best ways to enjoy homegrown watermelons! If you’re looking for more ideas to use up those watermelons, give one of these recipes a try:


That’s How to Plant Watermelon

Small watermelon growing on the vine.

On a hot summer day, nothing beats the flavor of fresh, juicy watermelon. With these tips, you’re sure to have a healthy crop of your own this summer. After learning how to plant watermelon you won’t want to go back to store-bought!

For more tips to help you grow the healthiest plants this year, visit the Seed Starting page on our website. There you’ll find tons of tips, tricks, how-to guides, product recommendations, and much more to help you have the best garden yet.