How to grow red mizuna

Red mizuna welcomes winter's chill. Plant while it's still cold for many happy returns, writes Mat Pember.

By Mat Pember
Illustration by Tom Bingham
In its regular green shade, mizuna is all right. With a nice texture and subtle bitterness it's a solid leafy green. But when it changes to red, this vegetable really lights up.
As a gardening non-traditionalist I don't pay much attention to Latin names, but on researching red mizuna I had something of a lightbulb moment. The name Brassica rapavar nipposinica actually reveals some useful information about this vegetable. Brassica is the family of vegetables from which hails the likes of broccoli, kale and cabbage. Rapa suggests turnip, and nipposinica obviously has something to do with Japan. Need I say more?
My love affair with red mizuna is still young, for it was only one winter ago that I grew it for the first time at our St Kilda East nursery. From June to October, red mizuna grew without fuss and with so much productivity. At a time when the cold weather can be a formidable foe for many edible plants, the winter thermostat seemed to suit red mizuna
If you're growing now from seed, propagate them in a mini greenhouse so that they're nicely incubated in the earliest weeks. Keep the soil damp and expect germination to be quick - usually within a week. This makes mizuna a suitable candidate as a micro-green. If you can wait two to three more weeks, however, the young seedlings will be ready for a permanent move to the patch.
When transplanting into pots, use a good organic potting mix that's free-draining and loaded with natural fertilisers. For planting in-ground, integrate compost into the soil to ensure adequate reserves of nitrogen for healthy leaf growth.
As with any edible plant, the more light you can generate for it the better it will grow, but don't be concerned if direct sunlight is scarce. Filtered, reflective and residual light will all contribute to your plants' needs.
Watering red mizuna is your main task. The plant is renowned for growing quickly, so keeping it hydrated by watering every second day (even in winter when temperatures and evaporation are low) is advisable. Despite its relationship with brassicas, which are known for their susceptibility to an array of pests, red mizuna is largely immune. Perhaps this is because it thrives in the cold when the cabbage white butterfly becomes more dormant, or it may just be that its colour and taste aren't palatable to pests.
For us, on the other hand, the taste and appearance are huge drawcards. Red mizuna has a sharp mustard bite combined with a hint of sorrel-like zest, these qualities intensifying as the plant matures. Generally the younger the foliage, the more subtle the flavour.
A quick grower, red mizuna can be harvested from a month old. To harvest, either pluck the outer mature leaves, allowing the younger, inner leaves to develop, or use the chefs' method of hacking it down to ground level.
Thankfully, due to the prolific nature of this plant, it's suited to both techniques. Perhaps the best quality of red mizuna is its longevity. If we happened to live in a perpetual winter this plant would thrive all year round.
Unfortunately, spring and summer are inevitable. As soon as the mercury rises, the plant's natural tendency is to go to seed and form flower heads. Picking them off as they appear will keep production rolling, and this battle can be fought for many a month, but in the end it will be lost.
It is one of the few things we can blame warm nights and sunny days for ruining.
Tip of the month: mulching
Many people think of mulching merely as a fast fix for unsightly weeds in the garden, but the practice fulfils a multitude of other important roles. Mulching suppresses weed growth, it helps retain moisture in the soil, regulates the temperature of the soil and provides nutrition to the plants. Here's what you need to know about mulch.
By definition, mulch could be rocks or bark, but for the vegetable patch we prefer to use pea straw, lucerne hay or sugarcane mulch, which all provide quicker and more meaningful nutritional benefit to plants as they break down. They are also responsible for drawing up worms from beneath the soil, bringing you powerful garden allies.
When mulching use a product that is easy to handle. Big, roughly chopped bales of straw are suited for farm-scale spaces, rather than pots and small patches; for these opt for a pulverised, finer grade. A step further is heat-treated mulching pellets that expand when hydrated. This also doubles as a low-grade party trick for visitors.