Growers normally try to delay mirliton sprouting by putting new fruit in paper bags and storing them somewhere cool. But if you get a winter or spring crop, you may want to get them quickly sprouted so they can be directly planted. Here’s an “incubation” trick that Joseph Boudreaux of Broussard taught me that speeds up sprouting.
Once you pick the fruit, place it in a shaded warm area with a constant temperature of at least 75-80°F to encourage sprouting. The warmer the better. In a sense, you are incubating the fruit since cooler outside temperatures promote dormancy and prevent sprouting. If storing them outside, use chicken wire or netting to protect the seed from pests that enjoy eating the new sprouts.
When kept warm like this, the fruit will normally begin to sprout within 10-14 days. Sprouting is defined by when the internal seed pushes its way to the large end of the seed and a small green shoot emerges. When that happens, it means the seed is viable and can be planted. It’s important to not distribute or sell the seed until it has sprouted because sometimes–especially with Spring mirlitons–the seed can look healthy but have no internal inner seed and will not sprout and grow a new vine (it’s called parthenocarpy).
The shoot should only be a few inches long if you are selling them because long shoots tend to break off at the base during planting–and once broken at the seed, shoots will not regrow. If the shoot has already grown several inches, you can safely prune it back, but leave a couple of nodes.
And that’s how you incubate your mirliton.