round) and it has no chilling requirement, probably because its native habitat straddles the equator where there are no true summers or winters.
Although it is native to an equatorial region, the Andean walnut occurs at an average altitude of 2,500 m, where the climate is temperate. Temperatures vary between −3°C and 25°C (such extremes can occur even in the same day). The cold tolerance is unknown, but frosts occur regularly where the Andean walnut grows. It seems resistant to pests and diseases. The trees are often found growing along stream banks and the boundaries of fields, where they regenerate freely.
Andean Region. This is potentially an extremely valuable species for the whole Andean region. Germplasm collections should be made throughout. Types should be selected for large nuts, thin shells, fast growth, and other qualities.
At the same time, other indigenous walnuts should be collected. These are probably less promising as nut crops, but they, too, are potentially valuable timber species. These include:
No cross-pollination is required for nut production in the Andean walnut, but apparently hybrids can be made if they are desired. For example, hybrids between J. neotropica and the common (“English”)