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How to Grow Cucamelons: 6 Tips for Growing Cucamelons

Wondering how to grow cucamelons? You’ve come to the right place. Cucamelons may look like a mouse-sized watermelon, but they taste like a cucumber with a citrus kick. Called “sandía de raton” (or “watermelon for a mouse”) in Mexico, cucamelons are also called Mexican Sour Gherkin and Mouse Melon

No matter what you call them, cucamelons are easy to grow and resistant to pests and disease. Learn how to grow cucamelons and add this crunchy, vitamin-packed fruit to your garden. 

How to Grow Cucamelons

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6 Tips for How to Grow Cucamelons

1. Understand how cucamelons grow

Cucamelons are a tender perennial; this means they are sensitive to frost but if cared for properly can live for several seasons. Over the course of a season, cucamelons develop an underground tuber

At the end of the season in cold climates, dig out and remove the tuber to overwinter in a sheltered location. Once the plant dies back in mild winter areas, mulch the ground around the roots well and it should survive over the winter and begin to regrow in the spring.

How to grow cucamelons

2. Plant cucamelons at the right time

Cucamelons thrive in warm, humid weather. Plant cucamelons outside after all danger of frost has passed in the spring, and nighttime temperatures have warmed to about 50℉. 

In the low desert of Arizona (and many other hot summer areas), here are the planting dates for cucamelons:

Start seeds indoors: January – March and July 15 – August

Plant transplants outside: February 15 – April and August 15 – September

In Arizona, spring-planted cucamelons may not produce until cooler temperatures come in the fall. You may get a spring and a fall harvest if you can keep the plant alive over the summer. 

The larger spring-planted cucamelon plants often yield a larger harvest than fall-planted cucamelons. The trick with growing cucamelons in dry, hot summer areas like Arizona is to have them survive the summer heat. 

How to grow cucamelons

3. Plant cucamelons from seed or transplants in the correct location

In all but the warmest areas, give cucamelons full sun. In very hot summer areas, grow cucamelons in a spot with afternoon shade. 

Plant cucamelon seeds ¼ to ½ inch deep. Seeds generally take between 7-14 days to germinate. Because cucamelon seeds germinate slowly, it can be difficult to start them outdoors. You may want to start seeds indoors 4 weeks before the last spring frost, and then transplant them outside. You can also look for transplants at local nurseries. 

Space cucamelon plants and seeds about a foot apart in a location with compost-rich, well-draining soil. 

How to grow cucamelons in square foot gardening:

Plant one cucamelon plant per square. Plant the cucamelon on the edge of the garden bed and give them something to climb. 

How to grow cucamelons in containers

How to grow cucamelons in containers: 

  • Grow one plant in a large 12-18 inch container (at least 5 gallons).
  • Give cucamelons in containers something to climb

4. Care for growing cucamelons

  • Plants tolerate dry conditions, but do best with regular watering.  
  • Fertilize cucamelon plants once or twice during the growing season with a high-potassium liquid fertilizer to encourage fruiting.
  • Once vines reach about 8 feet, pinch back growing tips to encourage branching and fruiting.
  • Cucamelons produce male and female flowers. Male flowers wither and die; female flowers develop into fruit after pollination.  
How to grow cucamelons

5. Give cucamelons something to climb

Cucamelons are a sprawling vine that can be difficult to contain. Provide a trellis for the tendrils to climb as the cucamelon vines grow. Growing cucamelons vertically on a trellis allows for better airflow and helps prevent damage from feet and pests. Ripe cucamelons grown on a trellis are also easier to spot and thus harvest.

HOW TO GROW CUCAMELONS

6. Harvest cucamelons at the right time

How to grow cucamelons

Cucamelons typically begin producing 65-75 days after transplanting. Harvest cucamelons when the fruits are the size of small grapes, firm, and bright green. 

Cucamelons left on the vine past their prime will soften and develop a yellow tint. Pick cucamelons often to encourage production. Leaving cucamelons on the plant signals to the plant to stop producing.

Eat cucamelons fresh like grapes (our favorite way) or slice them and add them to salads. Enjoy them pickled (so cute!) or even added to salsa

Harvested cucamelons will store for 5-7 days in the fridge. I love using these containers to help my produce last longer.

When to harvest cucamelons

Bonus Tip: Save seeds from cucamelons to plant and share

At the end of the season, leave a few cucamelons on the vine until they are very overripe, soft, and yellow. These are the perfect stage to save seeds from. 

How to save cucamelon seeds: 

  • Cut cucamelons in half and scrape seeds into a half-pint glass canning jar.
  • Fill the jar partway with water.
  • Allow the water to ferment for 1-2 days (not longer); this removes the gel covering around the seed that prevents germination. 
  • Remove the seeds and pulp that float to the top of the water. 
  • Rinse off the seeds that settle on the bottom of the jar, and let them dry on a paper plate.
  • Store in a paper seed sleeve in a cool, dry location.
Harvesting cucamelon seeds
Remove seeds
Harvesting cucamelon seeds
Let ferment in water for 1-2 days
Harvesting cucamelon seeds
Save seeds that settle on the bottom of the jar
How to Grow Cucamelons
How to Grow Cucamelons

karen

Saturday 3rd of September 2022

can i replant the tuber outside in may and will it be enough time to grow i am in a 5a 5b growing zone or should i star them inside

Angela Judd

Tuesday 6th of September 2022

Good question. You'll need at least 60-65 days of warm weather (if not more) If possible I would start them indoors.

Sande

Sunday 28th of August 2022

I ordered seeds from Amazon and started them in little peat pots in late April/ early May. I misted them daily in a south window. In late May I put them in the ground in a bed of garden soil and ran twine up from garden stakes to the fencetop. They took off and gave me soooo many cucamelons! The summer was hot and humid in NC. UPPER 90s most of July and August. They were in full sun. But about the third week of August I noticed tiny round holes. When I broke the melon apart there was a green worm where the hole was. Broke my heart!! Now they have stopped producing and I am so sad. I pulled the faded vines up today. Any advice for next year?? New location? Preventative spray? I think these were pickle worms.

Angela Judd

Monday 29th of August 2022

That's so frustrating, I'm sorry. Here are a couple of things you can do. Put floating row cover over the plants from the very beginning - especially at night when pickle worm moths are most active. You can also treat with Bt (Bacillus thuringiensis) an organic option that is harmful to caterpillars but not to other insects, etc. https://amzn.to/3CGQKuw

Phil

Friday 10th of June 2022

Beware putting immature plants in full sun! I took my young plants - more mature than seedlings, but still not very big yet - outside to "harden them off" a little. Big mistake. When the full sun hit them one afternoon they shriveled and dried up. I lost half of the plants I put out there. The plants I grew from seeds are SO delicate. I'm going to keep them indoors a while longer and then put them in a shady area outside after they grow a little larger. I got my best crop of cucamelons when I had two plants on my porch, in mostly indirect sunlight. They grew wild and gave me tons of fruit. I put some in pickle juice and they were delightful.

Susan

Thursday 30th of June 2022

I have one plant that has survived from seed that is about 8-10" long right now in a small pot. It's ready to be transplanted to a bigger container and placed outside, but being in NC heading into July, I'm looking to keep it alive. After reading your comment, I think I'll try it on my north facing porch that gets early morning sun. I was told cucamelons were hard to start from seed and they were not wrong.

Angela Judd

Friday 10th of June 2022

Thanks for the tips!