Goya – The Bitter Melon

One of the most popular aspects of Japanese culture throughout the world is its unique culinary traditions.  There are innumerable three, four, and five-star restaurants domestically, while sushi, teriyaki, and even teppanyaki have become well-known internationally.  Still, there are many delicious and healthy Japanese food items that have yet to hit the mainstream.  Today I hope to introduce you a bitter melon that can do more than fill your belly.

This article covers a lot!  I go from seed to dish so if all you want is prep or recipes, just scroll down to the heading you’d like.  If you’re interested in growing your own goya for food or as a green curtain check out all the sections!


Momordica charantia* is the scientific name for a bitter fruit popular in Japan and grown in the southern prefectures, primarily Okinawa.  Goya thrives on full sunlight and so it is prized as a food item that can be grown even in the harsh and hot summer months.  Goya is generally eaten before it ripens, which makes it relatively easy to cultivate, even for people missing a green thumb.

The goya plant is a vine that likes to climb.  Left alone, the vines tend to curve into the air until they collapse under their own weight.  Like watermelon or cucumber vines, the main stalks send out small tendrils that wrap around nearby objects to help support the vine.  When nets are used, goya can grow a story or more, sending out branching vines along the way.
Several weeks after germination, small yellow attractor flowers will begin popping up to attract insects that will help pollinate the plant.  After a few days, fruit bearing flowers will begin to develop with miniature goya just behind the flower.  If these are fertilized, the goya will grow in size.  The vines also sport wide, five tip leaves that pull in the warm sun, but will turn yellow if they end up in too much shade. There are many varieties of goya, some long, and others more wide.  The can be almost white in color to dark green. Their shading can sometimes make spotting the melons difficult since they blend with the leaves well.

Growing Goya

If you live in Japan, your local home store will probably start putting out baby goya plants around the beginning of spring.  If not, or if you feel more adventurous, you can buy seed packets or try to grow them from the seeds within a goya (if you do this, you’ll probably want to let it ripen rather than eat it).

As with most vine plants there are two approaches to germination.  The common method is to place two seeds in a small plastic pot with standard potting soil until the seeds germinate. You don’t need to pre-soak the seeds. It can take a week or more for this to happen.  If more than one of the seeds sprouts, you’ll want to pull one out.  Once the plant develops two major leaves you can then transplant it to your garden.  This method tends to produce fruit faster, but may not produce as much.

The alternative method is to simply plant your seeds in your garden.  This allows for a more natural root system, which means more of the initial growth will happen underground instead of where you can see it.  If you choose this method, you’ll have to prepare the ground ahead of planting and weed well while watering a wider area than just your germination pots. I suggest keeping a broken pot around the plant to help ward off insects and contain the area you initially water.

When deciding on a place for your goya, think about what you want from it.  In Japan, the summer and fall, goya’s growing season, is also known for typhoons.  You may want to plant in an area protected from the wind.  If you use a strong enough net, your goya may survive even typhoons.  You will also want an area that gets full sunlight at least half the day.  Goya is flexible in that it can be planted on balconies if you use pots instead of a garden.

Food or Shade?

If you want your goya primarily for food, you’ll want a larger area where you can set up a lower “tunnel” or area of netting that will give the goya plenty of room to spread out and soak up the sun.  You’ll want to keep the height down to a level that you can easily reach to cut free the fruit.

If you are more interested in goya’s shading properties and want to create a green curtain to shade a wall or window, then you can let the goya go much higher in the knowledge you might not be able to easily get to all the melons that develop.


Most home stores have netting readily available for purchase.  Easy to use netting is fine for goya provided you use a strong enough frame.  Goya spreads and tends to regrow over older growth.  As old leaves die, the older vines become larger central supports while new vines grow in available areas and produce new leaves.  All that growth will get very heavy.  For free-floating food trellising you’ll want either strong wood (bamboo works great) or metal to attach your net to.

High flying netting should be attached securely to a solid anchor at the top and bottom as well as horizontally to keep the weight of the plants from pulling in on the outer lines.  If you can, using a metal or wood frame is best, though you can get away with anchored ropes or wire. I have tried wire, rope, bamboo, and polyester ties (not suggested as the sun will break them down!).

The sturdiest was bamboo, plus it is eco-friendly since it grows so quickly. Once your net is ready you can transplant your seedlings or plant your seeds.  You should space them at least two feet apart.  I generally found four plants was plenty to create a healthy green curtain across two 6-tatami sized rooms


Once flowers being to bloom on your goya, you should begin watching for goya to form.  When they’re larger than about 4 inches (about 10cm) they can be harvested by cutting the vine just above the melon.  If you leave them, they can grow quite large.

Unfortunately it is almost impossible to time how long the goya will keep growing before ripening.  You can gently squeeze them, if they start to give a little they’re probably close to turning color.  Ripe goya turn yellow then bright orange within a day or so.  Inside the seeds go from hard green  and covered by fibrous white membrane to covered in a slick red cover.

Ripe goya essentially fall apart dropping the red seeds which tend to sprout rather easily if there is enough water.  You won’t want to eat the ripe goya.  Most goya usually finish growing within a week. Watering plays a big part to how big the goya grow, and how quickly they turn.  I’ve seen small goya turn, while some large ones keep going.


Goya plants like water.  You will want to water regularly to keep growth the same on your goya.  Changing water schedules can lead to misshapen goya (though they’ll be edible).  On sunny days without rain, I usually water in the morning and once in the afternoon.

As the plant grows, some roots may become exposed.  You can cover them with ripened goya you missed or extra potting soil.  You can also add occasional fertilizers.  Goya plants like the same mix as cucumbers.  I suggest asking your local garden shop, though if your soil is well prepared you may not need to add anything.

For potted plants, the larger the pot, the more room your goya will have to grow and the healthier it will be.  You can get away with long, low flower pots (the ones two feet long and about 1/2 a foot wide), but larger is probably better.  You don’t need overly deep pots as goya roots tend to spread more horizontally.

Preparing Goya

Goya is bitter, but supposedly of vitamins.  I’ve had great goya and very unfortunate goya.  Luckily they way  you prepare goya has a bigger say on the final flavor than at what point you harvest.  Slice the ends off the goya, then slice along the center along the length.  Use a metal spoon to scrape out the seeds and the white fiber that holds them in.  This will give you two long halves that are crescent-shaped.

If you plan on cooking the goya, you’ll want to slice the goya about 1/16 to 1/8 and inch in thickness.  If you are going for salad or raw applications then you will probably want to go as thin as you can safely cut (a mandolin might work best). Use a sharp knife and sawing motion so that you don’t break the goya’s shape.  Fill a bowl with water.  Dissolve some water and mayonnaise (I know, but it works).  Let the freshly cut goya hangout in the bowl for about ten minutes.  You can sprinkle more salt on if you’d like.  This helps cut down on the bitterness.  Rinse the goya.  You can use it immediately, or freeze it for later!

Goya in Food

Goya can be used in a lot of interesting ways, from fresh to fried.  In salads it adds a slightly bitter kick and crunch that pairs well with oil based dressings, tuna, bean sprouts, and other vegetables.   Goya can be used in tempura, chopped into any dish you’d use bell peppers, or stir fried with other root vegetables. Goya leaves can even be eaten, and are sometimes used in soups.

Here are some of my favorite goya recipes:


Goya Chanpuru – An Okinawan Favorite





Taco Rice with Goya







Easy Summer Goya Salad