This beautiful climbing plant is only hardy in the milder areas of the UK, where it can reach a height of 6 ft or more. It flowers freely in late summer and then dies down with the first hard frosts in the autumn.
Is Mashua | Tropaeolum tuberosum edible?
Mashua produces many edible tubers near the soil surface and can be quite heavy-yielding. In mild winter areas, the tubers can be left in the ground (though it would be a good idea to mulch them); in colder areas, they should be harvested and stored, much like dahlias. The tubers are quite popular in S. America, but they are probably best described as an acquired taste. The somewhat peppery flavour is improved considerably if the tubers are cooked and then frozen before eating them. (You can warm them up again if you like!) We have also found that the flavour is much nicer if the tubers are left in the ground and then harvested after being frosted. In the Andes, people consider the tuber to lower the sex drive, and many men refuse to eat it whilst recommending it for women! Clinical trials indicate a reduction of 45% in some male hormones when the tuber forms a considerable part of the diet, but no loss in fertility has been observed. The growing plant is resistant to diseases and insects; it contains nematocidal, bactericidal and insecticidal compounds. The main problem with growing this plant in the UK and similar climate areas is that the tubers are not formed until the shorter days of autumn, and if you get an early frost, then yields can be very low. The cultivar Ken Aslett is probably the best form available in the UK; it comes into flower earlier and produces larger tubers than the species type.
Tropaeolum tuberosum is known for attracting bees. It has nectar/pollen-rich flowers.
Known Hazards None known.
Habitats Mountain slopes and valleys. Moist wooded scrubby areas around 3000 metres in Peru and Ecuador.
Edibility Rating 4
Other Uses 2
Weed Potential No
Medicinal Rating 2
More information in the Database entry https://pfaf.org/user/Plant.aspx?LatinName=Tropaeolum+tuberosum