The gac cucumber or gac fruit (Momordica cochinchinensis (Lour.) Spreng.) comes from Southern China and Southeast Asia, it grows as far south as Australia naturally, but can be grown outside its native habitat. It is one of the healthiest fruits Mother Nature has ever produced.
This is truly a super food containing massive amounts of antioxidants. It contains elevated levels of carotenoids known as lipocarotenes, which also includes beta carotene. These carotenes enable cellular rejuvenation and vascular protection among other documented benefits.
Related to true cucumbers and melons it goes by various names which include spring bitter cucumber, baby jackfruit, spiny bitter gourd, fakkgaw, sweet gourd, gak cucumber and cochin-chin gourd. Unlike true cucumbers it is perennial, not an annual.
There are two varieties of gak cucumber. One is 1.5 inches to slightly over 2 inches in length the other is slightly larger reaching just shy of 4 inches in length. They are rounder than standard cukes and softer when fully ripe.
They start out as green and thorny and mature to a yellowish orange and eventually become more red, something like the Hmong red cucumber.
The pulp is also reddish orange. The skin is spined with short spikes and fairly thick. They reach maturity in 30 -60 days depending on a number of factors not the least of which is growing conditions.
Gac has a relatively short harvest season and must be ripe when harvested, it can not be harvested un-ripe and shipped like many other fruits and vegetables. which has made it commercially un-viable. Rarely is it found in markets, even specialty markets, it has to be locally grown.
In North America it will perform well is USDA hardiness zone 9 or warmer, it can be grown in summer months elsewhere but should be started indoors and transported out in early summer at best. If planning on growing it perennially, it should be kept indoors over winter.
Good specimens grown under the best of conditions can produce vines 20 – 25 feet long, although this is not the norm. A vining plant such as this requires a trellis or fencing, just like true cucumbers.
Gac seeds are larger than cucumber seeds and brownish red. The seeds have a small cavity or hole on one end, this hole should pointed downwards when planting them.
They are not self pollinating and require pollen from other plants to produce fruit, as many as possible in close proximity is needed to ensure adeqaute pollination as well as genetic diversity.
Germination rate is generally not spectacular, nor is it incredibly abysmal but you should anticipate that some of the seeds will never germinate. Germination takes up to two weeks, but under good conditions with good specimens it can occur in as little as 6 – 10 days.
Good drainage and aeration is important, avoid both clay soils. If starting in potting soil be sure to incorporate some vermiculite and or perlite.
Anticipate flower bloom about 2 – 2.5 months after planting. So long as you have several plants within close proximity Mother natures birds and the bees should be able to handle pollination. You can also try your hand at hand pollination, especially if you only have a few plants. See – Hand Pollination
Gac is a perennial, although it will generally produce flowers in its first season it does not always bare fruit. When it does produce in its first season it produces very little. By its second year you should begin seeing good harvests.
Although some of the monikers assigned to this unique produce include the term”bitter” – it is not bitter unless eaten unripe, in which case it resembles “bitter-cukes” which is caused by a substance known as cucurbitacin found in cucumbers, similar compounds are found in gac cucumber / fruit. When ripe it has a flavor somewhat like cantaloupe, although not quite as sweet. Its high carotene content adds a carrot like taste as well.