Cucamelon (Mexican Sour Gherkin) Plant Profile

Adorable Miniature Fruit with a Cucumber Flavor

closeup of a cucamelon

The Spruce / Autumn Wood

There are lots of beautiful vegetables you can grow in your garden, but if there is one that deserves to be called cute, it’s cucamelons. And it’s not difficult to see why they are also called mouse melons—the one-inch fruit looks like a watermelon that a mouse would lug home from the market. In Mexico, they are called sandita, which means little watermelon.

Botanically, cucamelons (Melothia scabra) are neither cucumbers nor melons. Although a member of the larger cucumber family (Cucurbitaceae), cucamelons are found in an entirely different genus than true cucumbers or melons.

Cucamelons have a unique crunch and a cucumber-like, slightly tangy flavor, which makes them great for eating raw, for making quick pickles in the refrigerator, as an additive for salsa or salads, or even as a garnish for drinks.

Cucamelons are usually direct-sown into the garden after all danger of frost has passed. The seeds germinate and sprout in 7 to 14 days, and reach maturity in 60 to 70 days.

Botanical Name Melothia scabra
Common Name Cucamelon, mouse melon, Mexican sour gherkin, sandita
Plant Type  Annual vines
Size  12 in. tall; 36- to 42-in. spread
Sun Exposure Full sun
Soil Type  Any well-drained soil
Soil pH  Slightly acidic (6.1 to 6.8)
Hardiness Zones  Grown as annuals in all zones
Native Area Mexico, Central America
Toxicity Non-toxic
cucamelon leaves and trellis

The Spruce / Autumn Wood

tiny cucamelons sprouting

The Spruce / Autumn Wood

Cucamelons growing from tiny yellow flowers
Cucamelons growing from tiny yellow flowers AnjoKanFotografie / Getty Images 
Cucamelons ready to harvest
AnjoKanFotografie / Getty Images

How to Plant Cucamelon

Cucamelons can be slow and erratic to germinate, so it’s best to start them from seeds indoors where you can better control soil humidity and temperature. Start the seeds three to four weeks before your 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 in sterile potting mix, 1/2 inch deep. Keep the soil moist at a temperature of around 70 degrees Fahrenheit. It can take up to 14 days or longer for them to germinate, so be patient.

After the seedlings emerge, thin them to one plant per pot. Three to five weeks after starting the seeds, when the seedlings are at least 2 inches tall, harden them off, then transplant them to your garden after all danger of frost has passed. Space the plants at least 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 a wire fence 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. If you grow cucamelos on a trellis, it’s easier to spot the fruit when harvesting without disturbing the vines. Round tomato cages, tomato trellises, or tomato towers work well for cucamelons.

Cucamelon Care

Light

Cucamelons need plenty of sunlight during their entire life cycle. As soon as the seedlings emerge, place them on a sunny windowsill, or under fluorescent plant lights placed 3 to 4 inches above the seedlings, on for 16 hours and off for eight hours. As the seedlings grow, raise the lights as needed.

Before transplanting the seedlings to your garden, gradually harden them off by giving them increasingly longer visits outdoors over the course of one week. Once planted in the garden, cucamelons need six to eight hours or more of direct sunlight each day.

Soil

Cucamelons can be grown in any type of soil as long as it’s well-drained. As with most vegetables, they benefit from the addition of plenty of organic matter. 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. If it doesn’t rain enough, water them slowly right at the soil level. Drip irrigation is best. Overhead watering should only be done early in the day so that the foliage can dry again 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 of Mexico and 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 three to four weeks old, fertilize the seedlings with a starter solution—a balanced vegetable fertilizer made with one-quarter of the strength indicated on the manufacturer’s instructions.

Fertilize the cucamelons again lightly by mid-summer but avoid a fertilizer high in nitrogen, because at this point, you don’t want too much leaf growth.

Varieties

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

Harvesting

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. To avoid damaging the vines, cut the fruits off the vine rather than pulling.

One plant only yields a handful of fruit at a time, so if you want more, either plant several cucamelons, or collect the fruit until you have enough for a dish. Cucamelons keep well in the vegetable crisper of the refrigerator for a few days.

Cucalemelons can be used in a variety of ways, including slicing to add to salads, chopped and added to salsa, or pickled and canned.

Common Pests and Diseases

Cucamelons are relatively resistant to pests 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 prevent mildew.

Also, aphids can affect the plant; organic solutions include citrus oil or insecticidal soap.

How to Grow Cucamelons in Pots

If grown on a trellis, cucamelons are great container plants. Unlike other vegetable vines, they are relatively lightweight even when loaded with fruit so there is less risk of them toppling over. Plant one cucamelon per container, using a general-purpose potting mix.