Guide to Growing Bitter Melon

Last Updated on April 10, 2024 by Real Men Sow

The Asian and Southeast Asian cuisines love bitter melon. You can stuff it with shrimp or pork and serve it steamed, pickled, curried, or with soup. Bitter melons have a bitter, mouth-puckering acquired taste. 

Bitter Melon is a vining vine and if left unpruned, it will grow in a similar way to squash, cucumbers, and watermelon, producing vines that can reach 13-16 feet in length. The fruits are oval and can be either smooth or wrinkled, and usually measure 8 inches (20cm) in length. 

However, they can grow to as long as 10 inches (5-25cm) in length. As the fruit ripens, its color changes from green to yellow and orange to orange. The flesh is similar to a cucumber in that it has a watery and crunchy texture.

Planting time

You can grow bitter melons in warm-season climates, such as tropical or subtropical heat and humidity. Growing them in areas where the daytime temperature is between 75 and 80°F (24-31°C) is also possible. 

Bitter melons can be planted in the late spring or early season. Plant bitter melons outdoors, or transplants to the garden, no later than two to three weeks after frost danger has passed and soil temperatures have reached at least 60-65°F (15-18°C).

Site for Growing Bitter Melons

Bitter melons thrive in warm and humid climates. To plant, choose a sunny area that is warm and well-lit. You can plant bitter melons in well-drained, compost-rich soil that has a pH of 5.5 to 6.8. 

Preparing the growing beds for planting is possible by adding aged manure and compost. Although bitter melons will tolerate soils that are less desirable, such as silty-loam or sandy soils, good drainage is crucial.

Yield

Each plant can produce between 10 and 12 fruits, with the possibility of a few more.

Companion plants of Bitter Melon

Beans and peas, squash, pumpkins, beans, and corn. Avoid growing bitter melons alongside potatoes or herbs.

Space and Planting

Place seeds in holes approximately half an inch deep (1.25cm) and 12 inches (30cm) apart. In each hole, sow two seeds. The seeds will germinate within 8-10 days. However, low temperatures and soil that is too dry or too moist can slow down germination. 

You can space vigorous plants that are trained on a fence or trellis 9-10 feet (32.7-3 meters) apart. To prevent fruit from rotting, plants that are allowed to spread out on the ground should be covered with straw or plastic mulch.

General Care of Bitter Melons

Trellising 

This can help reduce disease and make harvesting more efficient. A trellis should be 6 feet (6 meters) tall and wide, or slightly more, next to each plant. Once the vine reaches the top of the trellis, trim or pinch all lateral branches. This will encourage the growth of the upper branches and increase yield. 

The laterals should be pruned to a length of 2 to 3 feet (.6 to.9 meters). When the tip reaches the top, it can be removed. The plant will then produce more flowers and fruits sooner. A trellis allows the fruit to grow longer and straighter than those grown in the ground.

Water and feeding

For fruit development and growth, keep the bitter melon plants’ soils moist. The best way to feed your melon plants is with aged compost. A slow-release organic fertilizer, such as 5-10-10, can be added to plants at the beginning of the growing season. 

To add nutrients to the soil and retain moisture, side-dress plants with aged compost. Every third week of the growing season, give your plants a boost by giving them water with compost or comfrey.

Taking care

Trellised vines produce long, straight-growing hanging fruit. To prevent fruit from rotting, vines that are allowed to spread out should be covered with straw or plastic.

When the tips of trellised plants reach the support’s top, they should be pinched or pruned. Longer lateral branches should also be cut. This will increase the plant’s ability to produce more flowers and fruits. Prune the first female flowers; male flowers will follow female flowers.

Pollination of Bitter Melons

Most vines flower within 5-6 weeks of being planted. The male flowers are the first to open, and then the female blossoms within a week. Both are yellow. The ovary is the swelling at the base of female flowers. It resembles a small melon. Both blooms are visited by pollinating insects and bees. 

They transfer pollen from the male flowers to the females. Male blooms usually last only one day. They open in the morning, then fall from the plants in the evening. It is common for flowers to drop.

In two to four months, the ovary of pollinated male flowers will start to grow and mature. After 12 weeks, mature fruits are ready for picking. They will be bright green, juicy, and have bitter white flesh.

Hand pollination of Bitter Melons

Honeybees and insects pollinate them. If you see flowers, but no fruit, and there are no bees in your garden, you might suspect that pollination is not taking place. You can also pollinate cucumbers or squash by hand. 

Simply pick the male flowers and place the pollen on the female flowers by touching the middle of the male flowers to the center. Males have a smaller section between the flowers and the vine stem that looks almost like a small fruit.

Container Growing

Bitter Melon can be grown in pots. A container should hold at least 5 gallons (19 Liters) of potting soil. More is better. The container should drain well.

Pests

Spotted and striped cucumber beetles can attack bitter melons. Cucumber beetles may carry bacterial diseases, which can cause vines to fall. Infected vines don’t recover. Spray the adult beetles using rotenone or another pyrethrum-based insecticide. To avoid harming honey bees, spray all pesticides at night.

Bitter melons can also be attacked by fruit flies, which can spread fruit rot. If the fruit is less than an inch long, you can prevent flies from reaching it by wrapping it in paper bags or with rubber bands. Keep your garden clean of weeds. Weeds can harbor pest insects.

Diseases

Bitter Melon is vulnerable to many of the same diseases as squash and cucumbers, including fungal diseases like powdery mildew and downy mildew as well as rust and other rots, as well as watermelon mosaic viruses and bacterial wilts. 

Fungal diseases can be reduced by trellising, which increases air circulation around vines. Non-trellised vines can be protected from melons sitting on moist soil by using a straw or plastic mulch. Plants that are infected by viruses cannot be treated. Plant disease-resistant varieties are best.

Harvest of Bitter Melons

When the fruits reach 4 to 6 inches (10-15cm) in length, harvest bitter melon. This is between 12 and 16 weeks after they are planted. They will have a pear shape with light green skin and a few yellow streaks. Fruits that are left on the vine for too long will turn yellow and become bitter. The bitterness of different fruits on the same vine may vary. Immature melons can taste bitter, while overripe melons can taste bitter.

A thin layer of bitter melon flesh turns from orange to bright red when it is ripe. The flesh is surrounded by a hollow cavity that has a spongy white pulp and seeds. The fruit will look a lot like a cucumber, and it will be crunchy and watery.

Bitterness results from the alkaloid momordicin in bitter melons. The darker the bitter melon color, the bitterer and more intense the flavor. Pick melons every two to three days once they start to ripen. More fruits will grow the more you pick them.

Seed production

Leave a few fruits on each vine for next season’s seed saving. The mature fruits will split open and release white or brown seeds. Sort the seed and then dry it on a countertop. Store it in a cool place and it will keep for at least 2 to 3 years.

Storing and Preservation

Keep bitter melons in a paper bag or plastic bag in the fridge between 53-55°F. (11-12°C.). Use within 3 to 5 working days after harvest. To avoid accelerating the ripening process, keep bitter melon fruits away from other ripening fruit.

Real Men Sow
Real Men Sow

Hello, I’m Pete and I’m currently based in the west of Scotland, in a small place called Rosneath, where I’m exploring my garden adventures. I personally started gardening around 6 years ago and initially, I started out by growing my favorite fruits and berries, such as strawberries, Raspberries & Gooseberries. Since then I’ve added a lot of vegetables and working closely with my neighbor, it’s been a lot of fun.