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How to Grow Watermelon

Homegrown watermelon picked at the peak of sweetness tastes so much better than store-bought. Impress friends and family with your green thumb by adding this beloved fruit to your garden. Learn how to grow watermelon, and you’ll be enjoying juicy, homegrown watermelon all summer long!


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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 have both, learn how to grow watermelon with these tips.

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

1. Select the best variety of quality seeds for your climate and location

Select the best variety of quality seeds for your climate and location

In warm climates, most varieties do well. Some favorites include Crimson Sweet and Moon and Stars.

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 Desert King and Hopi Yellow.

In cooler climates, choose short-season varieties such as Golden Midget and Sugar Baby.

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

Select the best variety of quality seeds for your climate and location

2. Choose and prepare a good location for planting watermelon

  • Watermelon plants require a lot of space to grow and thrive, with some vines reaching up to 20 feet or more. Give them ample room. Planting at the edge of beds or growing watermelon vertically gives watermelon room to grow.
  • Before planting, amend the area with compost and/or aged manure. Boost the soil further with a balanced organic fertilizer.
  • Choose a site for planting that receives plentiful sunlight (at least 6-8 hours).
Choose and prepare a good location for planting watermelon

3. Plant watermelon seeds directly in warm soil

Wait to plant watermelon until the soil temperatures reach 21ºC (70ºF). Plant outside 2-3 weeks after your last frost date. Sow 3-4 seeds 2.5cm (1 inch) deep, 1.2-1.5m (4-5 feet) apart. Water well with seaweed emulsion after planting. Thin to the strongest plant when plants have 3-4 leaves

If using square foot gardening, plant shorter bush varieties, plant at the end or corner of a bed and plan on one plant per 2-3 squares. 

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. 

The best time to plant in the low desert of Arizona is from February 15th through March.  

If desired, start seeds indoors one month prior to planting outside. Because watermelons can be very frost-sensitive, it’s important to avoid planting until there is no danger of frost.


4. Water watermelon correctly for the best-tasting watermelon


5. Feed watermelon throughout the growing season


6. Mulch the plant and protect the fruit

Mulch plants well to prevent weeds and conserve moisture. 

Once the fruit is set, use cardboard or a melon cradle to lift the fruit off the ground to protect it from pests and diseases. 

Growing watermelon vertically? Use melon hammocks to support growing fruit. I use zip ties to attach the melon hammock to the trellis.

Use melon hammocks to support growing fruit.

Vertical Gardening Ideas

Looking for ways to add vertical space to your garden? This post shares 10 of my favorite ideas.



7. Harvest watermelon at the right time

Knowing when a watermelon is ripe is often the most challenging part of growing them.
Low-pitched thump when you hit it lightly.

Knowing when a watermelon is ripe is often the most challenging part of growing them. Here are a few things to look for: 

Knowing when a watermelon is ripe is often the most challenging part of growing them.
Look for three browned tendrils.
  • Three tendrils along the stem (going back to the root) end are brown, dry, hard, and curled.
  • The underside of the watermelon turns creamy yellow or white.
  • Low-pitched thump when you hit it lightly – practice thumping unripe melons to hear the difference.
  • The sheen of the watermelon changes from slick to dull looking.
How to tell when watermelon is ripe
The sheen of the watermelon changes from slick to dull looking

Comment below if you have questions about how to grow watermelon, or share tips and varieties of watermelon you’ve tried and enjoyed.


Tiffany

Thursday 29th of February 2024

I am thinking of growing watermelon vertically up a cattle panel trellis (in the shape of an arch) Would it work to plant them on the west side of the trellis and plant tomatoes along the east side? I’m thinking the watermelon could shade the tomatoes when the heat of summer hits. They would be in separate beds. I’m in AJ. Thoughts?

heather

Wednesday 10th of April 2024

@Angela Judd, would you need to cover the trellis in the middle of summer? I am interested in growing vertically but worried about being blasted by the sun in summer. Also if doing a 'V' trellis or triangle shape could you ideally grow any companion plants in the shaded part underneath?

Angela Judd

Monday 4th of March 2024

Interesting idea - seems like a good plan. Let me know if you try it and how it works out.

Ruby Feathers

Friday 28th of July 2023

My watermelons are beginning to turn yellow on top but are not ready to harvest yet. Everything else looks good. Can anyone please explain why this is happening? And are they any good anymore? Thanks for any help.

Angela Judd

Monday 31st of July 2023

It may be the heat and sunburn or sun scorch. Would be edible, but probably not very good.

Juan

Monday 19th of June 2023

My first time I like too grow Watermelon I love them I planted them in April but dont know if they are ready..

Angela Judd

Wednesday 21st of June 2023

Congrats! Use the tips in this article to help determine if they are ready to harvest or not. It can be tricky, for sure!

dina

Friday 26th of May 2023

Hi Angela, Huge fan. I have crimson sweet and also Kajari melons growing at present. I have used a water can to spray liquid kelp on the leaves as instructions on the bottle indicate and also to soak the ground. I've done both, once. But, there is no guidance as to how often I should do that. Could you please advise. Thank you so much

Angela Judd

Thursday 1st of June 2023

Usually about once every 3-4 weeks is the most I would do.

Don Engold

Monday 8th of May 2023

I'm new to watermelon growing. But the kids in the area will enjoy any success we have. Showing them food does not grow in a store. i'm trying two different variety of melons , black diamond and crimson sweet. Thanks for the tips.