Solanum quitoense

Solanum quitoense, Naranjilla, is a fast-growing, fruit-bearing tomato-relative from the humid highlands of northwestern South America where it is prized for its 'little oranges' - its sweet tasting fruit - and the juice they yield. In cold temperate regions like the UK, it is usually grown for its ornamental - if somewhat prickly - foliage and the fact that - like Ricinus communis - it quickly forms a large exotic shrub in just one growing season. The leaves are scallop-edged, covered in a fine hairs and are prominently latticed with purple veins which bear the prickly spines. Spines also develop on the stems.

Solanum quitoense does best in a rich well-drained soil, preferring warm humid conditions in shade or semi-shade with regular liquid feeding throughout the summer. Planted out after all danger of frost or persistent cold weather has passed it grows rapidly into a large exotic shrub, flowering in late summer and setting fruit. In UK conditions there is little chance of first-year fruit ripening as the onset of cooler weather in October inevitably brings the growing season to a halt. At this stage the intrepid grower has a decision: treat Solanum quitoense as an expendable annual or dig it up, pot it on and overwinter it indoors to give it a head start the following year.

If choosing the later course of action, it is best to cut back the roots somewhat and fit it into a modest-sized pot and prune the trunk hard - back to about 15cm - so that new growth is stimulated and the growing plant can then be potted into a larger pot in the Spring. Following such a regime will ensure the plant is already large by late May/early June when it can once again be planted outside to give it the best chance to set fruit in the heat of summer. If the British weather lets you down, you still get an enormous exotic plant and the opportunity to try once again the following year.