Japanese Mustard Spinach (Brassica rapa)
Komatsuna is a leafy Oriental vegetable popular in the cuisine of Japan, Taiwan and Korea. Although commonly known in the United States as “mustard spinach”, it is actually a closer relative to the turnip. Most parts of the plant are utilized; leaves, stems and flower buds. The leaves can be picked when 2-4” (5-10”) for baby salad greens. Use Komatsuna in any recipe that normally calls for spinach or pak choi.
Greens can be boiled, steamed, sautéed or stir-fried. Baby greens are great in fresh salads especially mixed with other Asian greens. Popular for salt-pickling in Asia. A delicious source of Calcium! Wash fruits, vegetables and herbs thoroughly before eating.
Use a fertilizer formulated for vegetables.
Fertile, well-drained soil.
Basic Care Summary
Plant in a reliably sunny spot. Prefers fertile, well-drained soil and cooler temperatures. Keep soil moist, watering freely in dry weather.
Select a sunny site, away from trees and close to a water source if possible.
Prepare the garden by breaking up the existing soil (use a hoe, spade, or power tiller) to a depth of 12-16” (30-40cm). Add organic matter such as manure, peat moss or garden compost until the soil is loose and easy to work. Organic ingredients improve drainage, add nutrients, and encourage earthworms and other organisms that help keep soil healthy. Give plants an extra boost by adding a granulated fertilizer formulated for vegetables or and all-purpose feed (such as a fertilizer labeled 5-10-5).
Remove the plant from the container. If plants are in a pack, gently squeeze the outside of the individual plant cell while tipping container to the side. If plant doesn’t loosen, continue pressing on the outside of the container while gently grasping the base of the plant and tugging carefully so as not to crush or break the stem until the plant is released. If the plant is in a pot, brace the base of the plant, tip it sideways and tap the outside of the pot to loosen. Rotate the container and continue to tap, loosening the soil until the plant pulls smoothly from the pot.
Dig the hole up to two times larger than the root ball and deep enough that the plant will be at the same level in the ground as the soil level in the container. Grasping the plant at the top of the root ball, use your finger to lightly rake apart the lower roots apart. This is especially important if the roots are dense and have filled up the container. Set the plant in the hole.
Check the plant label for suggested spacing and the mature height of the plant. Position plants so that taller plants are in the center or background of the garden and shorter plants in the foreground.
Plan ahead for plants that get tall and require staking or support cages. It’s best to install cages early in the spring, at planting time, before the foliage gets bushy. Vining vegetables can occupy a lot of space, so provide a trellis, fence, or other structure that allows the plant to grow vertically to maximize garden space.
Ideally water should only be applied to the root zone – an area roughly 6-12” (15-30cm) from the base of the plant, not the entire plant. A soaker hose is a great investment for keeping plants healthy and reducing water lost through evaporation. Hand watering using a watering wand with a sprinkler head attached is also a good way to control watering. If the garden area is large, and a sprinkler is necessary, try to water in the morning so that plant foliage has time to dry through the day. Moist foliage encourages disease and mold that can weaken or damage plants.
Thoroughly soaking the ground every 2-3 days is better than watering a little bit daily. Deep watering encourages roots to grow further into the ground resulting in a sturdier plant with more drought tolerance. How often to water will depend on rainfall, temperature and how quickly the soil drains.
To check for soil moisture use your finger or a small trowel to dig in and examine the soil. If the first 2-4” (5-10cm) of soil is dry, it is time to water.
There are several reasons to prune vegetable plants: to help contain a plant’s size, to promote bushy compact growth, to remove dead or diseased stems, and to promote larger, healthier fruit yields.
Flower buds can be pinched off to force the plant energy into fewer fruits that develop faster.
Vining plants can become invasive in a confined garden space. If necessary, entire vines can be removed down to the main stem to keep plants under control.
Never prune away more than 1/3 of the plant or it may become weak and unproductive.
Remove vegetables as soon as they mature. Leaving them on the plant any longer than necessary can affect flavor and texture, and mature fruit steals energy from younger developing fruits.
A well prepared planting bed enriched with organic matter such as compost or manure and a mild general-purpose, granulated fertilizer gets plants off to a good start. Give plants a boost later in the season with a fertilizer formulated for vegetables.
Fertilizers are available in many forms: granulated, slow-release, liquid feeds, organic or synthetic. Follow the package directions to determine how much, and how often, to feed.
Be sure to keep the garden well-weeded. Weeds take vital moisture and nutrients away from the vegetable plants.
|Height Metric Range||30-36cm|
|Space Metric Range||25-38cm|
|Available Colors||Green, Red|
|Companion Plants||Peas, Mizuna, Beets, Onion|
|Lowest Temperature||0° to 10°F|
|Lowest Temperature Metric||-18° to -12°C|
|Bloom Time||Grown for foliage|
|Plant Light||Full Sun|
|Hardiness Zone||7, 8, 9, 10, 11|