Achocha or caigua (Cyclanthera pedata) is an Central and South American vegetable in the Cucurbitaceae family. It is probably best known in the Andes, but it is grown from southern Mexico to Bolivia. It is somewhat similar to cucumber in flavor, but less so in appearance and growth habit. The immature seed pods are eaten. They range in size from roughly 2 to 8 inches. The smaller types are typically used whole and are a little bit like cucumber, but with a spongier flesh. The larger types are typically used for stuffing, with the interior scooped out and replaced by fillings of meat, beans, or rice. Immature fruits are delicious eaten raw, but older fruits need to be cooked. This is a good plant to grow in climates where cool summer weather or humidity make conditions challenging for cucumbers.
Varieties differ primarily in the size of the fruits. Some are small and are best eaten whole when young. Others are larger and are best eaten when more mature with the interior removed. We grow 8 accessions of achocha, some of which are probably duplicates.
Most achocha varieties tend to flower and fruit more heavily toward the end of the growing season in cool climates. In warmer climates, they may fruit earlier. Plants can grow very large when trellised and yields can be impressive where fall weather is mild enough to mature most of the fruits.
Like cucumber, achocha seed has a long life and retains good germination for five years or more. I have gotten better than 50% germination with seed that was stored for seven years at room temperature. Seeds should be planted about an inch deep. Germination appears to be fastest with a daytime temperature of 75F and a night temperature of 60F. Achocha will germinate nearly as well, although more slowly, down to about 60F day / 50F night.
There is a very similar relative of Achocha, C. explodens (previously C. brachystachya), the exploding cucumber. Like achocha, it is edible and I think the flavor is indistinguishable. The fruits need to be harvested while still immature, but the main difference is that they explosively dehisce, flinging their seeds several yards from the plant.