All You Need to Know About Planting and Caring for Mibuna

Are you interested in some of the lesser-known Asian greens? Then you should be growing mibuna. This fantastic plant is easy to plant and raise and provides tasty leaves for salads, soups, and more.

It’s a cool-weather crop, so if you’re looking for more fresh food that you can add to your diet, it’s the perfect option. Plus, the flavor is rich, complex, and downright delicious.

Whether you grow it indoors as a microgreen or outside in the garden, mibuna is a nutritious addition to your space.

All About Mibuna

Mibuna (Brassica rapa was. laciniifolia subvar. oblanceolata) is a relative of mizuna and part of the brassica Asian greens group (along with komatsuna). It hails from the Mibu region of Japan and is one of the dento yasai, or traditional heirloom greens, from the country.

Like its close relative mizuna, mibuna has long, narrow leaves. But unlike mizuna, its leaves are oblanceolate in shape and have smooth edges that aren’t heavily serrated.

Mibuna is full of Vitamin A, C, and K, as well as calcium, iron, and folate. If you’re someone who enjoys a fresh salad for lunch, then add some mibuna greens for an extra punch of nutrition.

If you live in USDA Growing Zones 4-9 you can plant this crop outdoors and everyone else can grow it indoors.

There are many cultivars out there, but most companies just sell the seeds under the species name. Look for ‘Green Spray,’ ‘Early,’ ‘Kyoto,’ and ‘Purple.’

Growing Mibuna From Seed

You can try growing mibuna outdoors or indoors, so it’s up to you what you prefer when planting your seeds. Firstly, let’s cover the basics of planting this green plant outdoors.

Mibuna seeds are quick to germinate, usually in just a few days, so you won’t need to wait long before you see the first signs of growth.

Outdoor Planting

The ideal time for growing mibuna outside is about two weeks before the last frost.

Place the seeds a quarter-inch deep and one inch apart in rich, loamy, well-draining soil. If you have sandy or clay soil, amend it first using well-rotted manure.

If you want to make the planting process quicker you can broadcast the seeds, but you’ll need to thin the seedlings out once they emerge.

That’s actually one of the nice things about growing mibuna. You can even eat the tiny little seedlings as microgreens, so feel free to dig into any seedlings that you thin out.

If you want to grow large mibuna leaves, you should thin to six inches between each seedling.

Water the seeds gently (so as not to disturb them) and thoroughly after planting and keep the soil moist until the seedlings emerge.

Indoor Planting

When you grow this green indoors, you can plant the seeds any time of year.

The most important thing is that you pick a container that is six inches deep and space the seeds one inch apart, whether you use individual containers or a seed tray.

Fill your chosen container with standard potting soil and sow the seeds. Cover with a quarter-inch of soil and water well. Place the container somewhere it will receive several hours of sunlight each day. Keep the soil moist but not wet as the seeds germinate.

Growing Conditions for Mibuna

Creating the right soil is essential for growing mibuna, as it is with most plants. You should have well-draining soil that is rich and loamy. Heavy clay or sand should be amended with organic matter like well-rotted manure or compost.

In terms of pH levels, you should aim for 6.0 to 7.5. You can easily check the pH of your soil with a home test kit or a probe, like this one from Justmetr.

For the most part, mibuna grows the best in sunny to partially sunny locations where there are between four to eight hours of sunlight a day. In hotter areas, provide more shade. This is a cold weather-loving vegetable and will bolt in heat.

If you’re looking to grow this green in winter, you can plant it in a greenhouse or cold frame. Those in Zones 8 or 9 can grow all year without protection.

The ideal soil temperatures for growing mibuna are between 40°-80°F, though it can handle below freezing for short periods. Mibuna is more tolerant of cold and less tolerant of heat than mizuna is.

Caring for Mibuna

Water is crucial for growing mibuna (and all crops). The plants need about an inch of water per week. If you don’t live somewhere with frequent rainfall, then you should do it by hand to ensure your plant gets enough moisture.

The best way to tell if your plant needs water is to stick your finger in the soil and see if it feels moist, like a well-wrung-out sponge. If it does, great. No need to add water. If it feels drier, get watering.

Be cautious about soaking the leaves. This can lead to fungal problems if the plant can’t dry properly. The best way to water mibuna is by soaking the soil and not the leaves.

If you like to water your plants with sprinklers, you should leave enough time between watering and nightfall to give the leaves enough time to dry completely before the sun sets.

Mibuna doesn’t normally need to be fed with fertilizer.

However, there are a few things you can do to boost the nutrients of your crop. Simply side-dress using well-rotted manure or compost. That way, you can make sure your plants have everything they need without using toxic chemicals.

Indoors, there’s no need to add any fertilizer if you used a good potting soil. Make sure that the plant is consistently receiving about six hours of sun per day, but keep it out of the direct sun in the heat of the afternoon.

Common Mibuna Pests and Diseases

Here are the most common pests and diseases to look out for when growing mibuna.

Pests

Aphids attack mibuna plants (and practically everything else in the garden) and can cause a lot of problems if you don’t deal with them early on. Usually, you won’t notice the bugs themselves, but rather the damage they cause.

Look for yellowing or stippling on leaves, as well as stunted growth. You might see a sticky substance on the leaves. This is known as honeydew and it’s the waste the aphids leave behind. This honeydew attracts ants and sooty mold.

Inspect your crop closely if you see these symptoms to determine if it’s aphids. You’ll probably see small spots of red, orange, or green moving around on the undersides of the leaves.

Luckily, a simple solution of soap and water can be applied to the infected area to get rid of these pests.

As well as aphids, you should also look out for cabbage loopers and slugs. Our guide to cabbage loopers can help you sort out the problem as these pests can be devastating.

Diseases

A few of the diseases that affect mibuna plants are bacterial leaf spot, downy mildewand white rust. You can prevent these diseases from spreading by being careful about your watering schedule, preparing the right growing conditions, and checking on your crop as frequently as possible for signs of a problem.

We have a guide on dealing with bacterial leaf spot that can help you figure out what to do if this disease strikes. We also have an article on downy mildew.

White rust is a fungus caused by pathogens in the Albugo genus. It’s common on brassicas and causes chalky white blisters to form on the undersides of the leaves. The leaves may also curl and be stunted.

Spray every few weeks with a copper fungicide the moment you notice the presence of symptoms or if any nearby plants are infected. Practice good crop rotation to avoid it in the first place.

Companion Planting

Some gardeners like to plant mibuna alongside other salad greens as you can harvest them all at the same time to make incredible salads. You can also plant with other cool-weather crops such as peas, carrots, beets, and spinach.

Try not to grow with too many other brassicas, as they tend to share diseases and pests.

Harvesting Mibuna

You don’t have to wait for mibuna to be full-grown to eat it. You can take the leaves at any point and new ones will continue to emerge until the plant reaches maturity, which takes about 45 days.

Or, you can leave them to reach complete maturity and harvest the entire plant at once.

It depends on how quickly you want your harvest and if you’d rather let them grow a little longer for a richer taste.

All you have to do is cut individual leaves with a pair of garden scissors, wash them, and prepare them for a meal. Or, slice the entire plant off at the base using a knife or pruners.

You can keep mibuna in the fridge for up to five days. Wrap it in a paper towel or cotton cloth and place it in the crisper drawer of your fridge.

Now, that you have your complete guide for growing mibuna at home you can start using it for cooking and sprinkle some flavor into your dishes! It can be used both cooked and raw, as with most Japanese greens.

You can use mibuna anywhere a recipe calls for mizuna or mustard greens. It has a stronger, more complex flavor than mizuna, which many people prefer.

To give you some inspiration, here are some recipes to try at home: