‘It’s Neither Melon Nor Cucumber’ – How To Grow Cucamelons For Their Interesting Fruit
Reviewed By COLIN SKELLY
Colin is a Horticulturist and Horticultural Consultant with experience in a range of practical and managerial roles across heritage, commercial and public horticulture. He holds the Royal Horticultural Society’s Master of Horticulture award and has a particular interest in horticultural ecology and naturalistic planting for habitat and climate resilience.
IN THIS GUIDE
Though rising sharply in recognition, Central American Cucamelon is still an exotic rarity in the UK.
This fast-growing disease-free climbing vine has attractive heart-shaped leaves, buttery-yellow flowers, and bears seriously cute teeny-weeny ‘mouse melons’.
Somewhat cucumber-like and citrusy, they are crunchy and zesty raw, and impart a tangy taste to salads and salsas.
What’s more, this plant provides a very ornamental ‘wall cover’.
This fruiting vine is a head-turner – for sure, in the ranks of garden exotica, Central American Cucamelon is way up there.
Overview
| Botanical Name | Melothria scabra |
| Common Name(s) | Cucamelon, Mexican Sour Gherkin, Mouse Melon |
| Plant Type | Fruit / Vegetable / Climber |
| Native Area | Central America |
| Hardiness Rating | H1C |
| Foliage | Deciduous; lobed heart-shaped leaves |
| Flowers | Yellow |
| When To Sow (Indoors) | April, May |
| Harvesting Months | July, August, September |
Sunlight
Preferred
Full Sun
Exposure
Sheltered
Size
Height
2.5 – 4M
Spread
1 – 1.5M
Bloom Time
June – August
Soil
Preferred
Chalk, loam, sand
Moisture
Moist but well drained
pH
Any
As the fruit resembles a doll’s house melon in appearance while being similar to cucumbers in taste, you would likely think that Cucamelon is a cross between the two.
Well, surprise! – it is neither melon nor cucumber.
Cucamelon or Melothria scabra belongs to a genus of flowering vines.
As it happens, M. scabra bears an edible (and very ornamental) fruit.
However, Genus Melothria does fall under Family Cucurbitaceae which includes both cucumbers and melons. So maybe there’s something there!1Melothria. (n.d.). Kew Royal Botanic Gardens. Retrieved March 14, 2023, from https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:30043481-2
Cucamelon is known by various names, these being Mexican Sour Gherkin, Mexican Sour Cucumber, Mouse Melon, and ‘Sandita’ – Little Melon in Spanish.
M. scabra is a deciduous fast-growing climber that will attain a height of 1-1.5M if grown as an annual, and 3M+ if grown as a perennial (by storing it dormant over the winter in the UK).
The flowers, at only about 4mm, are nothing spectacular but are cheery in their own right – they are flat with five splayed petals and of a bright, buttery yellow.
M. scabra is monoecious which means that the flowers (on the same plant) are either male or female.2Melothria scabra. (n.d.). School of Horticulture Plant Database. Retrieved March 14, 2023, from https://plantdatabase.kpu.ca/plant/plantDetail/1774
The male and female flowers of a monoecious plant pollinate amongst themselves.
Among Cucamelon’s noteworthy attributes are that it is among the most pest-resistant and disease-free of vines, is fairly drought-resistant, and is very productive, even prolific.
Habitat & Growing Conditions
‘Sandita’ grows in nature in a swath of land from Mexico down to Venezuela including most, though not all, regions of Central America.3S. (n.d.-f). Mouse Melon or Mexican Sour Cucumber, Melothria scabra. Wisconsin Horticulture. Retrieved March 14, 2023, from https://hort.extension.wisc.edu/articles/mouse-melon-or-mexican-sour-cucumber-melothria-scabra/
In its native range, it thrives in hot weather with temperatures hovering between 30-35°C.
In its own habitat Cucamelon is a deciduous perennial though in British climes it is usually treated as an annual and that’s because it is frost-tender, hardy only to Zone H1C.
That doesn’t mean you have to grow it as an annual; this vine can carefully be stored in a dormant state for the winter and re-planted in spring.
Indoors Or Outdoors?
As a bona fide two-for-one deal, Cucamelon climber not only serves up tasty treats, it also delivers ornamental bang-for-buck to the garden.
While this Central American native must be grown in a sheltered location where it enjoys full sun, its ‘garden status’ as an interesting ornamental suggests that it should be in a position where it can see and be seen.
“Although I’ve grown Cucamelon outdoors, it has only thrived in a polytunnel where the higher temperatures suit it far more than the vagaries of a UK summer,” shares Master Horticulturist Colin Skelly.
“The fruits are good to use in cocktails!”
Though the straightforward and practical thing to do is to have this climbing vine run up a trellis or tomato cage, to take advantage of its decorative value grow it against the latticework of a summer house, or climbing up a shed or even a wall of your house.
You could twine it around the post of a pergola. However, keep in mind that if it is tightly coiled around any upright, removing this delicate vine in late autumn for dormant storage will be very difficult; in such a case Cucamelon will have to be treated as an annual.
Though harvesting and maintenance would be difficult, you could grow these vines in hanging baskets so that they cascade over and down the rim for another type of aesthetic appeal.
How To Grow Cucamelon
The popularity of Cucamelon is on the rise but it is certainly not a plant that you can walk into your neighbourhood nursery and expect to find.
Nurseries that sell potted plants or bare-root vines are still few and far between. However, you will surely find some if you search online.
The best option is to buy Cucamelon seeds – these are much more readily available, both at garden centres and also online.
Though Cucamelon vines take their own sweet time to germinate, they are not particularly difficult to grow and care for, so seeds are really the way to go.
Growing From Seed
Cucamelon needs to be started indoors in the UK.
About four weeks before the last predicted frost date for your location is the ideal time.
Seeds should be sown in potting mix (which would include compost) in pots.
Consider using biodegradable pots to make transplanting easy and risk-free as young Cucamelon roots are tender, and disturbance or damage may affect the growth and yield of the vine, or even kill it.
Push seeds all the way into the soil with the pointed end facing up, one per pot.
You’ll need to grow several of these vines to produce attractive ornamental cover and to yield a good harvest so plan on starting at least six, preferably a dozen, seedlings keeping in mind that you will likely lose a few.
Germinate, and grow the seedlings indoors or in a greenhouse such that they get full sun and at a soil temperature of around 23-24°C.
Though Cucamelon is a very fast grower after it is up and running, it takes rather a long time to get up and running!
Be prepared to water patiently for two to three weeks while the seeds germinate.
Optimal soil temperature will markedly speed up germination – as the seedlings grow, reduce the temperature to 20-21°C.
Transplanting
After there is no chance of frost it is time to transplant the vines outdoors.
However, in the UK it would be prudent to harden them for a week to ten days before transplanting.
If you grew your Cucamelons in biodegradable pots the job will be much easier and free of both any stress or risk.
Space the growing vines 20-30cm apart.
If you want to grow Cucamelon in regions of the UK where the weather is particularly cold or unpredictable, consider doing so in a planter big enough for a vine plus a support framework.
This will give you the flexibility to shift the plant as the vagaries of the weather may dictate.
Plant Care
Soil Requirements
The soil can be clay, loam or sand as long as it is free-draining.
Though a soil pH from moderately acidic to slightly alkaline will do just fine, the ideal soil pH for Cucamelon is slightly acidic.
The location in the garden should enjoy full sun but should also be sheltered from the wind.
Feeding
About ten days after transplanting you may fertilise the climber with a 5-10-10 vegetable fertiliser, especially if the soil is not very fertile.
However, do not fertilise these sensitive vines as you would tomatoes or melons; apply fertiliser lightly and sparingly.
Watering
Water the vines moderately twice a week such that the soil stays moist but not wet.
Water at soil level, not on the foliage. A drip system will be very suitable for this plant.
Mulching around the vines, though not necessary, will be helpful, as it will deter weeds and also retain moisture.
Plant Support
Cucamelon need a support structure on which they can climb otherwise they will spread and creep untidily along the ground, with the attendant risk of slugs and rodents having an easy time with your fruit, and the fruit getting dirty or contaminated as well.
Furthermore, such a support structure is also essential to maximise the decorative appeal of Cucamelon climbing vines.
Practical options include a support structure of cane or bamboo, a trellis, or a tomato cage.
Overwintering
After the vine has ceased to bear fruit by late autumn, you can preserve your plant to flower again next spring.
Gently disentwine the climber from the support structure, and remove it from the soil taking care not to damage the main fleshy root.
Keep the root system in only slightly moist compost and store for the winter in an above-ground room such as a shed that will be protected from frost.
In mid-spring, plant the vine outdoors again. Fertilise it a week or ten days after planting it out.
Harvesting Cucamelon
Cucamelon vines will produce fruit from mid-summer to mid-autumn. Fruits form at the base of the female flowers.
Timing is important in picking these fruits so that they’re at their best.
Cucamelon must be harvested early, as soon as it is ready.
Sure, you don’t want to pick these fruits when they’re pea-sized but you don’t want to delay either, otherwise they lose that light, refreshing, and succulent mouthfeel and become tough or dense and unenjoyable, and also develop large seeds.
So how do you know just when to pick Cucamelons? The fruit will form just below the flower, which will wither as the fruit develops.
The fruit is ready for picking when it is right around an inch long and firm – neither hard nor soft – and there is no more flower.
Guideline aside, it’s really not a great mystery – a little experimentation and you’ll have it down within days.
What you do need to do without fail is that after the flowers appear, monitor the vines for pickable fruit every other day or even on a daily basis.
Snip off the fruits with a pair of secateurs; avoid trying to pull them off as the vines are delicate.
Harvesting will go very smoothly if you have those secateurs in one hand and a bowl in the other.
You can store Cucamelons in the fridge’s crisper but for no more than three or four days.
Common Problems
Cucamelon vine is well known to be pest-resistant and disease-free.
On occasion, a vine may get powdery mildew or aphids.
Powdery mildew can be avoided by watering at soil level and ensuring that the plant is not closed-in by trees, other plants, or structures so that it can enjoy good air circulation.
Though aphids only infrequently attack Cucamelon, they are among the most dangerous of pests as they are hard to control because of how very rapidly they breed.
You can either get and release ladybugs and lacewings at the site of the infestation or clean it and spray it with insecticidal soap, which is an organic product.
Do not attempt both methods in conjunction because soap will put off ladybugs and lacewings.
