Bitter melon, also known as bitter squash, bitter apple, bitter gourd, balsam-pear, and many other non-English names, is a widely grown vegetable, especially in the tropics and sub-tropics. It is classified in the Momordia genus within the Cucurbitaceae family and is indeed shaped much like the cucumber you may have growing in your backyard garden. Depending on the species grown though, its exterior may be light green and bumpy or warty-looking (for the longer “Chinese” type) or darker green and spiky-looking (shorter “Indian” type).

The cold weather-sensitive bitter melon plant will grow as a perennial in growing zones 9-11 but will thrive only as an annual in Minnesota during hot, humid months in full sun. Seeds should be started indoors 4 weeks before the last frost date and planted outdoors into warm, compost-rich soil or into a container. Seeds can also be sown directly into warm soil, however, getting these seeds to germinate can test the patience of any earnest Minnesota gardener.  A helpful and quicker germination method involves wrapping the seeds in a damp paper towel on a shallow plate over a seedling heat mat. This process may take up to 7 days and nights, depending on the age of the seeds, but usually results in tiny shoots growing quickly inside the paper towel. Using this method may also require hardening off to prevent shock from temperature changes.

At planting, trellis support should be provided. The bitter melon plant will produce long, light green vines with deep green, multi-lobed leaves and curly tendrils that appear delicate, but keep a tight grip on nearly anything within reach. 3 to 4 weeks after planting, the plants will produce bright yellow flowers; the male flowers appearing before the female flowers. 

Soil should be kept moist throughout the growing season, but not soaked. Momordia species can thrive on compost from household scraps but would otherwise benefit from a biweekly feeding of 5-10-10 slow-release fertilizer.

Two-three weeks after flower drop, female flowers will produce fully grown fruits. Chinese type bitter melons measure 6-10 inches in length and Indian type fruits will grow to an average of 4-8 inches. As with any vegetable, it can be tempting to see how large they will grow, but if left on the vine too long, bitter melons will overripen, burst open and release their seeds. The best indication of harvest readiness is the color of the fruit’s exterior. Bitter melons should be harvested before their skin turns yellow.

For ideas about how bitter melons are eaten, click on the Garden to Kitchen article!

Photo Credits:

Anita Oakman 1, 3

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