How to grow watermelon vertically

Learn how to grow watermelon and add this favorite summertime treat to your garden. Homegrown watermelon picked at the peak of sweetness tastes so much better than one bought at the store.  

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.

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7 Tips for How to Grow Watermelon

How to Grow Watermelon: 7 Tips for Growing Watermelon

1. 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 Mini-LoveBush Sugar Baby or Cal Sweet Bush. These varieties can be grown in one 4×4 foot bed or less. 

How to Grow Watermelon: 7 Tips for Growing Watermelon
Mini-Love Watermelon
How to Grow Watermelon: 7 Tips for Growing Watermelon
Hopi Yellow Watermelon

2. Choose and prepare a good location for planting watermelon

  • Watermelon needs plenty of room. Some vines reach up to 20 feet or more. Give watermelon the space it needs to grow well. 
  • Amend the planting area with compost and aged manure. Add a balanced organic fertilizer before planting.
  • Choose a location that gets plenty of sunlight
How to Grow Watermelon: 7 Tips for Growing Watermelon

3. Plant watermelon seeds directly in warm soil

Watermelon does best when directly sown once soil temperatures reach 70℉. Plant outside 2-3 weeks after your last frost date. Sow 3-4 seeds 1 inch deep, 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 and plan on one plant taking an entire 4×4 foot bed. 

The best time to plant in the low desert of Arizona is during the month of March.  

In cooler climates, start seeds indoors in 4 inch or larger pots 1 month before planting outside. Watermelon is very frost tender; wait to plant if there is any danger of frost.

How to Grow Watermelon: 7 Tips for Growing Watermelon

4. Water watermelon correctly for the best tasting watermelon

  • Water slowly and deep to allow watermelon roots to grow deep. 
  • Don’t get leaves wet. Wet leaves encourage diseases such as powdery mildew
  • As watermelon nears ripening, cut back on water to encourage sweetness.
How to Grow Watermelon: 7 Tips for Growing Watermelon

5. Feed watermelon throughout the growing season

How to Grow Watermelon: 7 Tips for Growing Watermelon

6. Mulch the plant and protect the fruit

Mulch plants well to prevent weeds and conserve moisture

Once fruit is set, use cardboard or a melon cradle to lift fruit off ground to protect from pests and diseases. Growing vertically? Use melon hammocks to support growing fruit.

How to Grow Watermelon: 7 Tips for Growing Watermelon

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

7. Harvest at the right time

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

  • 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.
  • Sheen of watermelon changes from slick to dull looking.
How to tell when watermelon is ripe

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

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How to Grow Watermelon: 7 Tips for Growing Watermelon
How to Grow Watermelon: 7 Tips for Growing Watermelon
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19 Comments on How to Grow Watermelon: 7 Tips for Growing Watermelon

    • Yes, just be aware that grow bags dry out more quickly. Use the largest bag you can and fill it all the way up with good potting soil. Keep it watered well and feed it regularly.

  1. I live in central Oklahoma. Can I plant my watermelons in March? And also, can they grow up a tomato cage?

    • Not sure of your local planting dates. Check with your local extension office to see if they have a planting guide they would recommend. Watermelon vines grow very large, probably too large for a standard tomato cage – if you do grow watermelons vertically be sure to provide support (a hammock of some sort) for the growing melons.

  2. I am in Phoenix and our Ali Baba watermelons just sprouted. But our raised beds are only about 6 inches deep. Will they survive?

    • Keep them well watered, apply a several inch layer of mulch, and feed regularly throughout the season. Hopefully your soil is good and they should be fine.

    • If you see female fruits withering and not forming fruit they aren’t being pollinated. You may need to try hand-pollinating them.

  3. How would you rate the flavor of the two varieties you suggest for Phoenix? I was hoping to grow some classic flavored, more sweet watermelon.

    • Crimson sweet may be a better choice if you are looking for a traditional sweet type watermelon. It also grows well here.

  4. If you have multiple fruits at various stages of ripening, how do you know when to cut back water? Or should I be pinching some fruits off?

    • Good question. I try to keep the fruits to 1-2 per plant so if one is still growing it can be tough to cut back on water. For the sweetest melon grow one per plant and cut back on watering just as its ripening.

  5. Some of my crimson melons are having a gourd shape to them. Is that anything to worry about? I also noticed one was a bit soft.

    • The one that is a bit soft may be rotting for some reason, go ahead and pick that one. The others may have had some trauma or pollination issues – see how they do. If they continue growing they should be fine.

  6. My watermelon is taking over the raised bed and moving on to the next bed, where I have peppers and tomotoes. I guess it’s very happy.. but my other plants are not. What would you recommend ? How do you keep them from speading to the other boxes? Do you have a video showing the garden area for melons? Should I add trellis around the box ? Thank you in advance. Ev

    • Hi, yes you could give it something to climb, otherwise it will spread. I like to plant them (and pumpkins, winter squash, etc.) on the end of my beds so they don’t go onto other beds.

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