How to grow Bitter Melon

Where to plant

Bitter melon needs full sun, warmth and rich, well drained soil, and a strong trellis or fence to climb. Seed germinates only in warm, moist soil, and the vines stall in cool weather.

In Florida, think twice before planting. UF/IFAS assesses bitter melon as invasive and not recommended in all parts of the state, and the Florida Invasive Species Council lists it as a Category II invasive. Birds spread the seeds from ripe, split fruit into hammocks, pinelands, dunes and swamp edges. If you do grow it there, pick every fruit while green and never let any ripen and split.

Elsewhere it is a summer crop: sow after the last frost in spring in Texas, the Gulf South, California, the desert and the Mid-South, and in May or June across the North. Pacific Northwest summers are too cool for a reliable crop, and in Alaska it needs a tunnel or greenhouse. In Hawaii it grows all year.

Choosing a variety

UF/IFAS describes two main types. Chinese types, such as China Long, are larger, about 8 to 12 inches (20 to 30 cm) long, smooth, light green and warty. Indian types are shorter and smaller, with rough, dark green skin and pointed ends. Seed is sold mostly by Asian vegetable specialists.

How to plant

1. Wait for warm soil after the last frost. The hard seed coat makes germination slow, and seed may fail in cool or dry soil.
2. For an earlier crop, start seed in pots in a warm spot and transplant carefully once the soil outdoors is warm.
3. Sow about an inch (2 to 3 cm) deep at the foot of a trellis about 6 feet (1.8 m) high.
4. Space plants about 3 to 5 feet (1 to 1.5 m) apart along the trellis.
5. Guide the young vines onto the support. Tendrils form once the plant has four to six leaves.

Watering and feeding

Keep the soil evenly moist through the growing season and mulch to hold moisture, watering at the base rather than over the leaves to limit powdery mildew.

Dig compost into the bed before sowing and feed with a balanced fertilizer through the season, as you would for cucumbers. Too much nitrogen gives a mass of vine and fewer fruit.

Pruning and care through the year

• Train the vines up the trellis, which keeps the fruit straight, clean and easy to find.
• Bitter melon has separate male and female flowers and needs bees to set fruit. Female flowers have a tiny fruit behind the petals. If fruit is not setting, transfer pollen from a male flower to a female flower in the daytime with a small brush.
• Pick fruit often while young. In Florida, remove every fruit before it can ripen and drop seed.

Harvesting

Start picking about 50 days after sowing in warm areas. Harvest while the fruit is firm and light to medium green, before it starts to turn yellow. As it ripens, the fruit turns orange, grows more bitter, splits open at the end and drops its seeds.

Store picked fruit in the fridge and use within a few days. Regular picking keeps the vine producing.

Using it

Slice the green fruit and scoop out the seeds and pith. UF/IFAS notes it is stir fried in Chinese cooking with garlic, egg, pork or fermented black beans, and in Indian dishes the slices are marinated in salt and tamarind before frying with spices.