Cucamelon Plant Profile (Mexican Sour Gherkin)

Adorable Miniature Fruit with a Cucumber Flavor

Cucamelons (Melothia scabra)

AnjoKanFotografie / Getty Images

There are lots of beautiful vegetables you can grow in your garden, but if there is one that deserves the attribute “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. They are a member of the cucumber family (Cucurbitaceae) but their own species.

Cucamelons have a unique crunch and a cucumber-like slightly tangy, sour flavor, which makes them a great addition for eating raw, and adding to refrigerator quick pickles, salsa, salads, and even use as garnishes for drinks.

Botanical Name Melothia scabra
Common Name Cucamelon, Mouse melon, Mexican sour gherkin, Mexican miniature watermelon, Mexican sour cucumber, Sandita
Plant Type  Herbaceous annual
Mature Size  36 to 42 inches spread, and 12 inches height
Sun Exposure Full sun
Soil Type  Any well-drained soil
Soil pH  6.1 to 6.8
Bloom Time  Summer
Flower Color  Yellow
Hardiness Zones  8
Native Area  Mexico and Central America

How to Grow Cucamelon

As a native of Mexico and Central America, cucamelons require a long, warm, sunny growth period. They are slow to germinate and slow to grow, that’s why in any temperate climate, they are best started indoors. But you will be rewarded with a long harvest until the last days of summer.

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

Growing from Seeds

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, 0.5 inch deep. Keep the soil moist at a temperature of around 70 degrees F. It can take 14 days or longer for them to germinate so patient.

After the seedlings have emerged, thin them to one plant per pot. Three to five weeks after starting the seeds, when the seedlings are at least two inches tall, harden them off, then transplant them to your garden. Space the plants at least 2 feet apart.

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, three to four 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, protect them from too much sunlight by gradually hardening them off for one week. Once planted in the garden, cucamelons need six to eight hours or more of direct sunlight.

Soil

Cucamelons can be grown in any type of soil as long as it’s well-drained. As with all 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 there is a chance that you damage the plant when weeding.

Water

Cucamelons need moist but not saturated soil, about one to two inches 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 when the foliage can dry again before sunset, which reduces the risk of disease.

Temperature and Humidity

Cucamelons are frost-sensitive and need a warm, temperate climate.

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 that point, you don’t want too much leaf growth.

Grow cucamelon on a trellis or fence to keep it off the ground
Grow cucamelons on a trellis or fence to keep them off the ground. Kitty_Lusby / Getty Images

Growing on a Trellis

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.

Growing in Containers

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, and follow the instructions for growing vegetables in containers.

Harvesting

Harvest cucamelons when they are one inch maximum. 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. Cut the cucuamelons off the vine rather than pulling to avoid damaging the vine.

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.

Common Pests/Diseases

Cucamelons are relatively resistant to pests. Powdery mildew is the most common disease. Also, aphids can affect the plant.