How to Grow Cucamelon (Mexican Sour Gherkin)

cucamelon growing in the garden

 

Olga Rozhkova / Getty Images

There are lots of beautiful vegetables to grow in your garden, but if there is one that deserves to be called cute, it’s the cucamelon. It’s not difficult to see why they are also called mouse melons: The 1-inch fruit looks like a watermelon that a mouse would lug home from the market. Botanically, the cucamelon (Melothria scabra) is neither a cucumber nor a melon, though it is part of the larger cucumber family (Cucurbitaceae).

A fast-growing, vining plant, the cucamelon is a frost-tender perennial in tropical climates but is most commonly grown as an annual. It should be planted in the spring. Small yellow flowers in the late spring to early summer are followed by the striped green fruits, which are around the size of a grape. The flesh of the fruits is white. Cucamelons have a unique crunch and a cucumber-like but slightly tangy flavor.

Common Name Cucamelon, mouse melon, Mexican sour gherkin, sandita
Botanical Name Melothria scabra
Family Cucurbitaceae
Plant Type  Annual, fruit
Size 1 ft. tall, up to 10 ft. wide
Sun Exposure Full sun
Soil Type  Well-drained
Soil pH  Acidic (6.1 to 6.8)
Bloom Time Spring, summer
Hardiness Zones  2–11 (USDA)
Native Area Central America

How to Plant Cucamelon

When to Plant

Cucamelons are usually direct-sown in the garden after all danger of frost has passed in the spring. The seeds germinate and sprout in seven to 14 days and reach maturity in 60 to 70 days.

Selecting a Planting Site

A sunny spot with well-draining soil is key for growing cucamelons. Container growth is also an option. Make sure no nearby taller plants will shade the cucamelons as plants leaf out in the spring.

Spacing, Depth, and Support

Plant seeds about 1/2 inch deep, and space plants roughly 2 feet apart. Cucamelons don't take up nearly as much space as other vine vegetables, but it's still a good idea to grow them on a trellis or other support structure because it keeps the fruit off the ground where it can rot in humid weather. Also, the vines are very tender and are easily injured when moved. So if you grow cucamelons on a trellis, it's easier to spot the fruit for harvesting without disturbing the vines. Round tomato cages, tomato trellises, or tomato towers also work well for cucamelons.

Cucamelon Plant Care

Light

Cucamelons grow best in full sun, meaning at least six hours of direct sunlight on most days. But they can tolerate a bit of shade and might appreciate some afternoon shade in hot climates.

Soil

Cucamelons can be grown in any type of soil as long as it’s well-drained. They like a slightly acidic soil pH. And as with most vegetables, they benefit from the addition of organic matter. So work some compost into the soil before planting, especially if you don't have rich soil. Mulching helps to keep the soil moist and maintain an even soil temperature. Adding mulch also helps to keep weeds under control. Cucumelons have shallow roots; the less you need to weed around them, the less chance there is of damaging the plant.

Water

Cucamelons need moist but not saturated soil. About 1 inch of water per week is best. If it doesn’t rain enough, water them slowly right at the soil level. Drip irrigation is ideal. Overhead watering should only be done early in the day, so the foliage can dry before sunset, which reduces the risk of fungal disease.

Temperature and Humidity

Cucamelons are frost-sensitive and thrive best a warm, temperate climate that approximates their native setting in Central America. The seeds will not germinate in soil below 60 degrees Fahrenheit. These plants prefer high humidity levels over arid conditions.

Fertilizer

When they are 3 to 4 weeks old, fertilize seedlings with a starter solution: a balanced vegetable fertilizer made with 1/4 of the strength indicated on the label. Another light fertilization in the midsummer will help to promote fruiting.

Pollination

Cucamelons self-pollinate from male and female flowers on the same plant with the help of the wind and garden pollinators.

Cucamelons ready to harvest
AnjoKanFotografie / Getty Images
Cucamelons growing from tiny yellow flowers
Cucamelons growing from tiny yellow flowers AnjoKanFotografie / Getty Images 
cucamelon leaves and trellis

The Spruce / Autumn Wood

tiny cucamelons sprouting

The Spruce / Autumn Wood

Types of Cucamelon

Cucamelon is a unique heirloom plant with no cultivars or hybrids developed.

Cucamelon vs. Cucumber

Cucamelons look a lot like tiny cucumbers, and they have a similar flavor. But there are some clear differences. Cucamelons have slightly more of a rounded appearance while cucumbers are more elongated—not to mention that cucamelons are generally much smaller than cucumbers. Flavor-wise, cucamelons taste quite similar to cucumbers except they have a hint of lime-like tartness.

Harvesting Cucamelon

Harvest cucamelons when they are no more than 1 inch in diameter. If you let them grow larger, they will become seedy and much less palatable. Make sure to check for fruit at least every other day, starting around 60 days after planting. To avoid damaging the vines, cut the fruits off the vine rather than pulling.

Cucamelons keep well in the vegetable crisper of the refrigerator for a few days. They can be used in a variety of ways, including slicing to add to salads, chopped and added to salsa, or pickled and canned. They even can serve as a garnish for drinks.

How to Grow Cucamelon in Pots

If you don't have the garden space for cucamelons, growing them in a container paired with a trellis is a great option to maximize your vertical space. Unlike other vegetable vines, cucamelons are relatively lightweight even when loaded with fruit, so there is less risk of them toppling over. Use at least a 5-gallon container with drainage holes. An unglazed clay container is a good option because it will be sturdy and will allow excess soil moisture to escape through its walls. Add only one cucamelon plant per container.

Pruning

Pinch back the tips of vines in the spring and early summer to encourage more branching. This consequently will result in more flowering and fruiting.

Propagating Cucamelon

An easy and inexpensive way to propagate cucamelons is simply to save seeds from the fruits. Here’s how:

  1. Leave a few fruits on the vine at the end of your growing season until they are overripe and yellow. 
  2. Remove the overripe cucamelons from the vine, and cut them in half.
  3. Scrape out the seeds and pulp. Discard the pulp, and put the seeds in a jar of water for one to two days. 
  4. Dispose of the debris and any seeds that have floated to the top of the jar. Remove the other seeds, and rinse them. Then, let them dry thoroughly in a single layer.
  5. Store the seeds in a sealed paper packet in a cool, dry spot. Aim to use them within a year for best results. 

How to Grow Cucamelon From Seed

Cucamelons can be slow and erratic to germinate. You can direct-sow seeds after the threat of frost has passed or start them indoors around three to four weeks before your projected last frost date. Use biodegradable pots to avoid disturbing the tender roots when you transplant the cucamelons to your garden later.

Plant two to three seeds per pot about 1/2 inch deep in sterile seed-starting mix. Keep the soil moist and at a temperature of around 70 degrees Fahrenheit. It can take up to 14 days or longer for seeds to germinate, so be patient.

After the seedlings emerge, thin them to one plant per pot. When the seedlings are at least 2 inches tall, harden them off and then transplant them to your garden after all danger of frost has passed.

Potting and Repotting Cucamelon

Use a quality all-purpose potting mix when potting cucamelons. It's best to plant them in a container that will accommodate their mature size, as repotting can be damaging to the roots and the vines.

Overwintering

Because cucamelons are typically grown as annuals, overwintering isn't necessary. However, it is possible, though not always successful, to keep a container cucamelon plant indoors for the winter and bring it back outside in the spring. Bring it inside before the first fall frost, and water just so the soil doesn’t dry out completely. Bring the plant outside the following spring once frost is out of the forecast, and resume watering as usual.

Common Pests and Plant Diseases

Cucamelons are relatively healthy when compared to similar vining plants. Powdery mildew is the most common disease, but it is rarely serious. Good air circulation and careful watering to avoid splashing soil spores onto the plant will help to prevent mildew. Also, aphids can affect the plant; organic remedies include citrus oil or insecticidal soap.

FAQ
  • Is cucamelon easy to grow?

    Cucamelons are fairly easy to grow as long as they receive enough sunlight and warmth and have a support structure or space to grow.

  • How long does it take to grow cucamelon?

    Cucamelons typically will be ready for harvesting around 60 to 70 days after planting.

  • Does cucamelon come back every year?

    Cucamelons are perennial in tropical climates, but most gardeners grow them as annuals.