How to Grow Watermelon 

Guest Post from ​Kirstine LeMaster

Growing watermelon, from planting to harvesting, plus recipes too!

I thought it would be great to do an article about how to grow watermelon. I mean, what better patriotic fruit than a watermelon, right? 

How to Grow Watermelon

If you did not plant any watermelon this year, then I hope this article will be helpful next year. As always, I have included some great recipes and a few 4th of July ideas (see recipes at the bottom of this page). So let’s get started!

Choosing the Right Variety of Watermelon

Watermelon.

Deciding which watermelon variety is the best can be difficult. But here are a few of the most popular varieties. 

Harvest Moon—If you’re going for smaller size, this is your variety. Harvest Moon is a seedless, sweet, watermelon verity. It produces small to medium sized fruit, and it is a higher producer and an early ripening variety. 

Sweet Polly—One of the main reasons why this type of watermelon is liked so much is because it can be grown in any region, plus it is seedless. On average it takes eighty-eight days to mature, and it is a higher yielding plant. 

Sugar Baby—Takes seventy-eight days to ripen, and it is very important that this plant receives full sun. The Sugar Baby’s “Brix” is listed as 10.2, making one of the sweetest water melons. “Brix” is a term used by commercial watermelon growers to describe the amount of sugar in a plant.

How to Grow Watermelon

Watermelon plant.
    Details on how to grow watermelon.  
  • Plant when temperature reaches 70º
  • Plant 4 seeds 1 inch deep
  • 2 feet apart (length) per 5 foot width
  • Cover ground with black plastic
  • Water well/fertilize weekly
  • Harvest 75-100 days after planting

Preparing Your Soil for Growing Watermelon

Learning how to grow watermelon isn’t that hard. Northern growers should choose a variety that is early ripening because of the shorter growing season.

LOTS OF WATER, FERTILIZER, AND SUNLIGHT!

These are the most important factors to growing great watermelon. When the temperature reaches 70º, it is time to plant. Watermelon like a soil pH (Potential Hydration) of about 6 - 6.8. You can find out the pH levels of your soil with an inexpensive soil testing kit from your local gardening store (prices range from $8.00 - $25.00). Once you’ve tested your soil (or maybe you already knew you soil type), it is time to prepare it.

Clay Soil—compost, peat moss and coarse sand (not beach sand).

Sandy Soil—aged manure, sawdust, humus, and peat moss.

Silt Soil—gravel, compost, well rotted horse manure, fresh straw, and coarse sand (not beach sand).

Planting Watermelon

Now that we have established a foundation for the soil type, we need to focus on how to grow watermelon in the right type of soil. You should prepare your watermelon beds one to two weeks in advance. Be sure they are located in a sunny spot; watermelon like 8-10 hours of sun daily. When you dig or till your soil, be sure you are going deep—watermelon loves room to spread. Create a 5 foot wide bed and rows 18 – 24 inches apart (you should be able to get two hills in a 5 foot wide row). Create hills by gathering the dirt together; this will allow for the watermelon to retain a larger amount of water and nutrients. Cover your garden beds with black plastic, which will increase you temperature.

If living in a Southern state, it is optional to start the seeds indoors. It is very important for Northern growers to start their seeds one month before planting. If not, your watermelon won’t have a long enough growing season. If starting indoors, plant seeds one inch deep in potting soil and leave in a sunny location (be sure to keep damp). It takes about ten days to germinate if the temperature is 70º, or three days if it is 90º. When planting outdoors make an x in the plastic and drop in four seeds one inch deep. After sprouting (which should take 10-15 days), thin the seeds to two plants. Water your plants weekly to get healthy watermelon. When the seeds start to flower, you need to fertilize and water weekly so the plant can support the fruit it bears.

Harvesting Watermelon

If you don’t want a large watermelon but planted those seeds, then for the entire life of the melon, do not water weekly or fertilize. This will insure a lack of nutrition, which therefore makes your watermelon smaller. You will know it is time to harvest when the underside of the watermelon turns from white to a bright yellow. Also when the watermelon vine is twisted, it will break relatively easy; however, if it is not ripe, it most likely will be hard to get off.

How to grow watermelon doesn't end with the growing. Watermelon should always be stored in the fridge once it is picked; uncut watermelon will store for about two weeks sometimes three. To store cut melon just wrap the cut end in plastic wrap and store in the refrigerator. The plastic will ensure it does not absorb any of the other foods' odors (it will store for about three days).

Watermelon Diseases

Watermelons are one of those plants that people either have huge disease problems with or none at all. Here are the diseases that effect learning how to grow watermelon.

  • Anthracnose
  • Bacterial Fruit Blotch
  • Downy Mildew
  • Gummy Stem Blight
  • Powdery Mildew

It is said that because of the humid climate, eastern growers have a much larger problem with diseases then western growers. If living in the east, follow some of the following guidelines to help you control your watermelon diseases.

  • Choose resistant plant varieties (mainly that are western grown).
  • Do not save your seeds.
  • Do not compost your watermelon leaves.
  • Clean your garden area EVERY FALL.
  • Apply copper sprays and sulfur powders weekly.
  • Use Neem oil.

Alright, I know this seems like a lot, but in the end it is worth it. Since there are quite a few diseases I don’t have time to go into remedies for all of them, so I will choose the most problematic one—Anthracnose. Anthracnose is a fungal disease that is extremely hard to eradicate. It overwinters on seeds or leaves and is spread by wind, rain, insects, and garden tools. This disease occurs usually in fall through spring under wet cold conditions. When a plant is affected by this disease, the leaves will typically turn a tan or brown color (sometimes orange), and then curl and fall off. Generally, after the leaves fall off, it will continue up the vine.

I know, you're thinking, “This is practically unconquerable!” Well, not quite. Being conscientious about what you plant and where can help tremendously. Be sure to disinfect your garden tools after using. Do not compost your leaves, and if you do, be sure it reaches a temperature of 140 to insure the disease is dead. Neem oil is from a tree native to India and Pakistan. When sprayed on plants, it kills all insects and diseases. It is, however, not poisonous to mammals, birds, bees or plants. (To avoid ladybugs, spray plants in early morning or late evening, once a week). Neem oil is available at Wal-Mart, Amazon, Tractor Supply, Target, Home Depot, and Ace Hardware. I highly recommend Diatomaceous Earth for western growers who are trying to control their insects—it works amazingly!

Fun Fact

Watermelon was named the official state vegetable of Oklahoma in 2007, causing some controversy because it’s really a fruit.

4th of July Watermelon Ideas

Have you ever tried cookie cutters on watermelon? Well now’s your chance! So grab those star cookie cutters are start cutting! (Add blueberries and pineapple to complete the Red, White (yellow), and Blue look). Other ideas:

  • Watermelon Sorbet
  • Watermelon Piña Colada
  • Watermelon Lime Dixie Pops
  • Watermelon Yogurt Pops

Watermelon Recipes

Okay, before we get started, let's go over some of the benefits.

Watermelon Benefits

  • 92% water
  • Vitamins B5, A, B6, & C
  • Copper—often lacking in western diet
  • Helps lower blood pressure
  • Reduce insulin resistance
  • Reduce muscle soreness after exercise
  • Contains Citrulline—linked to improved metabolic health
  • Calcium—boosts collagen production
  • Potassium—hydration and moisturizing
  • Magnesium—for youthful, radiant skin
  • Lycopene—natural sunscreen
  • Antioxidants

Watermelon Face Mask Recipe

Ingredients:

  • ¼ of a small watermelon
  • Oily skin— ½ banana & 3 drops tea tree oil
  • Dry skin—1 teaspoon organic yogurt & 3 drops lavender oil
  • Normal skin—1 teaspoon honey (melted)

Directions:

Chop watermelon into chunks (extract seeds if desired). Pour watermelon and whichever skin treatment applies to your skin into a blender. Blend until smooth. Apply to skin and let set for 15-30 minutes. Wash off with cold water and pat dry. (Note: Watermelon is an absolutely fabulous moisturizer because it contains so much water. It is especially great for oily skin because it gives it a deep and gentle moisturizing.)

Watermelon Pina Colada Recipe

Ingredients:

  • 2-3 cups watermelon
  • 1 cup chunked pineapple
  • 1/2-1 cup milk
  • 1-2 cups ice

Directions:

In a blender combine watermelon, pineapple, and milk. Blend until smooth. Add ice and blend. Serve cold. Makes 4-6 cups.

Watermelon Pina Colada Recipe.

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Growing Watermelon Tips
How to Grow Watermelon from Seed

About Kirstine

​Kirstine

​Kirstine LeMaster lives with her family in Western Colorado.

She loves playing Celtic and country music, riding horses, milking cows, working in the garden, and cooking, as well as crocheting, sewing, babysitting and learning Spanish.

She enjoys writing for SimplyCanning.com, while working to improve her photography and gardening skills.

Page last updated: 3/20/2020.

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