JAPANESE VEGETABLES IN THE GARDEN
By Helen Krayenhoff
Since its founding in Oakland in 1917, the Kitazawa Seed Company has been an important source for commercial and backyard growers interested in raising Asian vegetables. Among the Kitazawa offerings are seeds for many traditional or heirloom Japanese vegetables, including a specific group known as dento yasai, which date back to the Edo period (1603-1868). These come mostly from the Kyoto region, where winters are cold, summers are hot, and the water is pure and plentiful, and through the centuries have been carefully selected and grown for their unique shapes, vivid colors, and high nutritional value.
Kitazawa’s Maya Shiroyama says it is becoming more difficult to find open-pollinated varieties, like dento yasai, since many seed houses in Japan prefer to market hybrids. Gardeners who learn how to save seed play an important role in keeping the dento yasai and other heirlooms available. Maya recommends the varieties described below for East Bay gardeners wanting to grow dento yasai and other vegetables used in basic home-style Japanese cooking. All are items that appear on ingredient lists in the Japanese Farm Food cookbook. Visit the Kitazawa online catalog at Kitazawaseed.com for many more ideas on good things to grow.
Eggplants are popular in Japanese cuisine, and the dento yasai ‘Kamo’ variety is one Maya suggests. The glowing deep-purple fruits of this round, flat-bottomed eggplant can weigh up to half a pound and offer dense, rich-flavored flesh. Eggplants need heat to germinate and warm weather to thrive and produce. Transplant seedlings to a sunny outdoor spot with rich soil late April through early June. Harvest often to keep the plants producing.
Kabocha (Japanese pumpkin) is easy to find at the farmers’ markets, but if you have room in your garden, there’s great satisfaction in harvesting your own. Maya suggests trying out the venerable dento yasai variety named ‘Shishigatani.’ Plant in mid-spring and give the vines lots of room to wander. Maya determines fall harvest time by looking for light-brown, distinctly warted skin, and corky, dry-looking striped stems. For better flavor and storage longevity, cure harvested squash for a couple weeks in a shady, well-ventilated place.
Cucumbers are beloved in modern Japanese cuisine. Easy to grow, the heat-tolerant ‘Sooyow Nishiki’ variety has thin, dark-ribbed skins with fine white spines that can easily be removed by washing. Most often eaten raw or lightly dressed in salads, it offers a sweet flavor and lovely crunchy texture. Sow inside in late March and harden off the plants when large secondary leaves appear. Wait to plant until the stems are tougher and less prone to slug and snail attack. If you want straight fruits, Maya recommends training the vines up a trellis or tomato cage so they can hang unimpeded. If you find the fruit isn’t setting, your garden may lack pollinators. Check Kassenhoffgrowers.com under Growing Tips for information on how to hand-pollinate to solve this problem. Growing other cucurbits (cukes, zukes, and squash) in your garden may give you better luck.
WARM-SEASON GROWING TIPS
Plant these in your garden from April through June for harvests from summer until the temperatures fall too low. In milder areas, warm-season crops can produce right into December. These plants need room to grow and good air circulation to stay healthy. Water deeply and less frequently to help the roots reach down into the cooler moist soil. Try to keep water off the leaves.
Sometimes called spinach mustard, Komatsuna, is a versatile and super easy to grow member of the dento yasai. When young, it is very mild and can stand in for spinach or chard, but the mustardy flavor becomes stronger as this brassica matures into a huge plant. Harvest before the petioles (leaf stems) become tough. Maya says the florets or flower buds are delicious. She suggests sowing every few weeks for a constant supply of young plants.
Mizuna, a turnip relative, might be the dento yasai best known to Westerners. Maya is among the many who like the sweet mustard flavor that its durable leaves add to salad mixes. Scatter the seeds in a garden bed and you’ll have a great “cut-and-come-again” crop that will re-grow several times, provided you are careful how you cut it: Take only the top three-quarters of the leaves and do not damage the part from which they emerge. Let a few plants mature into heads and you can enjoy their stronger flavor in a quick stir-fry.
Daikon (giant white radish) is a revelation to the eye and palate. A good variety for our area is ‘Tokinashi, All Season,’ which has long (up to 14 inches) and beautiful smooth white roots that are great fresh, cooked, or pickled. Grow it from seed in place: Transplanting this (and other root crops) can damage development. Maya explains that amended and well-worked soil is a must for the best results.
The delicately flavored turnip called ‘Tokyo Market’ is another dento yasai. It can be harvested when small and eaten tops and all. Maya says the tops are used in a traditional “quick pickle.” As with daikon, it is best to direct-sow seeds and thin to final spacing. Make sure you eat those thinnings!
Try ‘Beka Santoh,’ a loose head type of Chinese cabbage that Maya recommends for its favored use in Japanese home cooking. It grows quickly, and the outside leaves can be harvested in about a month. Wait a little longer and full heads will form. When the plant bolts (sends up a flowering stalk), this cabbage remains very sweet and tender, unlike many varieties that become bitter at this stage. The yellow flowers are tasty, but Maya prefers eating the florets or flower buds.
Shungiku (edible chrysanthemum) is a wonderful aromatic addition to salads. Older stalks with flowers are used in tempura. Starts of this dento yasai will transplant well, and it’s quite cold hardy, so plan to sow in the autumn and harvest in spring. If you fall in love with it, try sowing successively to keep young plants available. The ‘Oasis’ variety grows well here. Maya says that the plants get quite large and benefit from pinching so they will produce more tender side shoots.
COOL-SEASON GROWING TIPS
Many cool-season Asian vegetables, such as bok choy, komatsuna, nappa cabbage, and mustards, are members of a familiar family of plants known as brassicas, so growing them is a lot like growing kale, collards, and broccoli. Daikon is simply a much larger version of the cute round radishes we plant for the kids every spring.
Many brassicas can be started in late summer and sown every few weeks in succession until the soil temperature is too cold for seed germination. Purchased plant starts or homegrown seedlings started in a warmer environment can be planted out into the garden any time here in the East Bay, as long as the soil isn’t too wet to work.
Cabbage caterpillars and moths, along with slugs, snails, and aphids, are the main pests associated with this family of plants. Slugs and snails can chew down newly emerged seedlings with amazing speed. Covering the soil around the seedlings with a quarter inch of oat bran helps mitigate the damage, since the slimy crawlers don’t like to slide on it. It’s not 100 percent effective but is definitely nontoxic.
White cabbage moths are easy to spot as they flutter prettily through your plants. Just realize that they are laying their yellowish eggs on the undersides of the brassicas’ leaves, and when the eggs hatch, small green caterpillars will emerge and do a lot of damage. Check the undersides of the leaves daily and wipe away the tiny eggs with your fingers. Anchoring a floating row cover around the plants before you see the moths can keep them at bay.
Aphids are more of a problem when the weather warms in the spring, but a hard spray with the garden hose will blast them away. A spritz of highly-diluted dish detergent applied after sunset will kill them, but you’ll have to repeat this a few times to get all the emerging generations. Keep in mind that the most efficient and effective way to control these garden pests is to create a welcoming habitat for the predators that like to eat them.