Solanum muricatum Seeds | Pepino Melon
LATIN NAME: Solanum muricatum
COMMON NAME: Pepino Melon
Plant Profile
The plant is a low, spreading evergreen shrub, usually under a metre tall, with grey-green leaves that carry a soft pubescence over a surface that feels like felt. The stems are succulent and brittle and the whole bush is short-lived in the way of a pepper plant, fruiting hard for a few seasons and then declining. The fruit is a large berry, roughly egg-shaped and often eight to fifteen centimetres long, which ripens to a pale cream or soft yellow and is usually marked with purple or violet stripes on the sunny side.
The flowers hang in small clusters and are shaped like a shallow bell, blue-violet with darker veining and a yellow-green centre, which is the classic nightshade advertisement for a particular kind of bee. The anthers are fused into a cone and release pollen only through small pores at the tip, so the flower cannot be pollinated by just any insect. It needs a bee that can grip the cone and vibrate its flight muscles, and bumblebees are the usual partners.
The cultivated pepino has two close wild relatives that grow in the same mountain valleys, and they are the likely source of the crop, which fits with what the fruit’s distribution shows: it was already grown across the Andes before Europeans arrived, from Colombia down into Chile. Aiton described the species formally in the eighteenth century, and although it travelled widely in the nineteenth, it never became a major crop anywhere. New Zealand and Australia now grow it as a minor commercial fruit, and it survives elsewhere as a garden novelty.
Science & Biotechnology
The plant carries a count of twenty-four chromosomes and is self-incompatible, so pollen from a flower on the same plant will not set fruit. A single clone in a greenhouse will flower beautifully and produce nothing at all, which is the commonest reason a grower gives up on the species. Keep at least two distinct clones close together, let the bumblebees in when the first flowers open, and set fruit with some confidence.
Uses & Benefits
Almost every part of a Solanum carries steroidal glycoalkaloids, and the pepino is no exception: the leaves, the stems and the green fruit are bitter and not to be eaten. What makes the species unusual is what happens during ripening, when the astringent, bitter notes in the pulp fall away and the fruit becomes mild, fragrant and juicy, with a texture closer to a soft pear than to a melon. That change is the whole difference between a wild Andean berry and a market fruit.
Because seed is scarce and seedlings vary, the pepino is propagated vegetatively. Softwood cuttings taken in spring from healthy shoots root readily in a gritty mix under cover, and a low branch laid on damp soil will layer itself if you pin it down and wait. Commercial planting material is often raised by nodal culture in a laboratory, which gives clean, uniform plants quickly, and that is the practical route to a named clone without carrying pests on the cuttings.
Growing from Seed
Ripe pepino is eaten fresh with lime and a pinch of salt, and the watery, lightly perfumed pulp makes an excellent sorbet. The fragrance is closer to honeydew melon with a cucumber edge than to anything sugary, which is why it pairs well with chilli, mint and cured ham rather than with cream. In the garden it works as a trailing container plant, with the fruit hanging over the rim looking far more exotic than the plant deserves. The stems are too soft to hold themselves upright once they carry fruit, so either let the plant trail over the side of a pot or a low wall, or tie the main shoots to a short stake and let the laterals hang. Fruit resting on wet soil rots at the tip, so slip a piece of straw or a saucer underneath anything that hangs low, and thin crowded clusters to three or four fruits.
Sow the seed on the surface of a fine, free-draining mix and cover it with a thin scattering of vermiculite, then keep the pan warm and lightly damp under cover. Once the seedlings are up, move them somewhere bright and cool rather than warm, because a night temperature near fifteen degrees suits the plant better than the tropical heat that suited the sowing. Pinch the growing tip when the plant has six or seven leaves to force side shoots, and pot on steadily until the roots fill the container.
Our Take
Pepino is the plant I recommend to anyone with a cool greenhouse and a taste for the unusual. Buy two clones, keep them dry at the roots but humid in the air, and give them a cool winter. If you like that soft Andean fruit flavour, Solanum quitoense brings a sharper tang, the African scarlet eggplant is the easiest relative to grow from seed, and passion fruit will climb over the same greenhouse roof.
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