As we approach the middle of March enjoying the warm weather we have had recently, many gardeners are looking forward to putting in cool season crops. Among those are beets, Cole crops, peas, radishes and similar plants. Among those “similar plants” why not include Asian vegetables? These ethnic crops have become popular in current cuisine and some are hardy to early spring planting. Others show up later in the summer season.
You might consider some of the five easily-grown varieties featured by the National Garden Bureau in 1999, which they dubbed the ‘Year of Asian Vegetables.’ These same five were featured in last Tuesday’s Homefront column as tasty additions to the menu with their history and suggestions on using them.
The transitional plants, which are hardy to cool spring weather include Daikon, a type of Chinese radish; Pak Choi (Bok Choi), a type of Oriental lettuce; and Snow Peas, related to the English peas we all grew up with. The two summer plants are Asian Eggplant, featuring smaller, more colorful, tender fruits grown on more compact plants; and Asparagus bean (yardlong) which looks similar to snap beans but has a flavor more like asparagus.
Daikon, a root crop, grows best in full sun in rich, loose, deep soil which allows the plant to grow quickly and the long roots to develop best. Plant these early this spring or in late summer for fall harvest.
Heat tolerant varieties will grow during the summer months. Sow seeds about 1/4 to 1/2 inch deep in rows 12-24 inches apart.
Thinning seedlings is critical for healthy roots, so thin seedlings to 8-12 inches apart. In raised beds, thin the plants to eight inches apart in all directions. Do not let the plants dry out too much between waterings to keep roots tender. Add fertilizer four weeks after planting using a formulation higher in phosphorous and lower in nitrogen which develops leaves at the expense of roots. The most common pest problem is root maggots.
Plan to harvest 50 to 60 days after sowing — if you leave the plants in the ground too long after they mature, they become pithy.
Pak choi is also excellent for spring planting in full sun but in a somewhat cool spot. They need rich, loose, very well-drained soil, so enrich your soil with organic matter and use raised beds if your soil is heavy. Plant pak choi in very early spring and again in mid to late summer for the fall garden. Start seeds indoors two to three weeks before the average date of last frost and transplant when danger of frost is past.
Place in individual pots to avoid damage to roots.
For fall crops, sow seeds directly in the garden 1/4 to 1/2 inch deep three to four inches apart and then thin to 8 to 12 inches apart. Plant in rows two to two and a half feet apart or space them a foot apart in raised beds.
Fertilize about every six weeks with a balanced fertilizer.
Their most serious plant pest is cabbage worms, cabbage root maggots and flea beetles. Growing under floating row cover helps keep these pests out or spray frequently with bacillus thuringiensis to prevent worm damage.
This crop matures quickly, and you can begin harvesting loose leaves as early as 30 days after sowing. Allow 50 to 60 days to form harvestable heads. Harvest outer leaves in the cool early season weather and inner leaves as the days become hotter. Cut the entire head, which will 3-4 pounds.
Snow peas, like beans, are legumes and do not need excessive nitrogen fertilizer. Plant in soil with plenty of organic matter to help retain moisture and choose a site with full sun. All snow peas need some sort of trellising — even the dwarf varieties — to produce vigorously. Lightweight trellises are sufficient if secured well.
Plant snow peas early in spring between March and May spacing crops out about two weeks for successive harvests. Plant again in mid-July for fall harvest.
Soaking pea seeds 24 hours or sprouting before planting gives them a head start in our cool ground in spring. Plant when the soil temperature reaches 45 degrees and the soil is dry enough to till. Plant the seeds one to two inches deep in prepared soil, two to three inches apart in rows 18-24 inches apart.
Keep snow peas well-weeded, but do not cultivate too near the roots which are shallow and very vulnerable. Turn the plants into the garden rather than pulling them to make the most of their nitrogen fixing ability.
Harvest snow peas 50 to 60 days from sowing when peas are just beginning to swell inside the pods — only about five to seven days after they flower. Pick regularly to keep the plants producing. They will stop producing well when the weather gets hot.
Asian eggplant, Solanum melongena var. esculentum, belongs to the nightshade family, Solanaceae, with tomatoes, peppers and potatoes.
Transplant eggplant in full sun in rich, well-drained soil. If your soil is heavy clay, add plenty of organic matter and create raised beds. They grow best in warm soil and require a long growing season, so start seeds indoors 10 to 12 weeks before the expected date of last frost or purchase starts from a nursery and transplant them outside after all danger of frost is past.
Allow 18 to 24 inches between plants in rows 30 inches to three feet apart or plant in raised beds allowing 24 inches between all plants. Add a complete fertilizer before planting and add more fertilizer half way through the season and again after the first fruits are harvested. For best production, water regularly keeping the soil moist, but not wet.
The National Garden Bureau recommends picking off the first few flowers to force the plant to set more fruit. You may want to stake Asian eggplant like tomatoes to encourage more attractive fruit.
Watch for verticillium wilt which shows up as yellowing of the bottom leaves. If a plant in your patch becomes infected, remove and destroy it. Crop rotation of all solanaceous plants will help reduce danger of infection from verticillium. Since this disease is transmitted by flea beetles, you can reduce problems by growing the plants under floating row cover until it begins to bloom.
Plan to harvest this crop in late summer when the fruits are about six inches long and the skin is glossy and firm. If the fruit begins to lose its gloss, it may become bitter. Discard spongy or brown fruits. Cut fruits from plants using a knife or pruning shears to avoid tearing the plants.
Asparagus beans grow best in soil that is loose about 8 to 10 inches deep and moderately fertile. Too much nitrogen causes beans to produce leaves at the expense of beans. Asparagus beans are true beans which means they are legumes and enrich soil by trapping nitrogen in nodules on their roots. They make their own food and leave some nitrogen behind for future crops. It is not necessary to fertilize asparagus beans again after planting unless your soil is poor in nutrients.
Plant in an area of full sun and put in poles and strings to trellis these climbers. These are tall plants, so allow seven feet for climbing. Do not be hasty in planting these beans until after the date of last frost as they wither in cold weather and thrive in heat. Plant seeds about two inches deep in loose soil and about one inch in heavy soil and place them three to four inches apart in rows eight inches apart. You should begin harvesting beans about two months after sowing and a single sowing in late spring will usually produce until fall frost. Harvest when the beans are about half the diameter of a pencil, before the seeds have filled out inside and when they still snap when bent. Check plants daily since continuous picking keeps the plants producing, and the plants will stop producing if beans are left to ripen.