Grow shiso (perilla) all year round in Australia
Shiso / しそ, also known as perilla, is a popular herb in Japan and Korea and known for its unique flavour and health benefits. While traditionally grown in Asia, it is possible to grow shiso year-round in Australia with a little TLC. Here are some tips to help you successfully grow the shiso herb in your Australian (or elsewhere) garden.
Getting started
There are different varieties of shiso with the main two being aojiso (or green Shiso) and akajiso (red (aka) but it's more purple). Its scientific name is Perilla frutescens var. crispa. You're more likely to come across the green shiso as it's by the far the most common.
The red shiso has a slightly different and more subtle taste, I've found when grown here in Aus. It was a lot stronger in flavour in Japan and used more for pickling and other things. Here are the kanji and wikipedia links for the two varieties:
Sourcing shiso
Your local gardening centre may stock some seed packets. Our local one in Perth stocks small packets that seem to be sourced from a Korean supplier. There are a handful of seed suppliers in Australia that also stock the purple when it's in season. It's unlikely you'll find seedlings in your garden centre, it's just not that popular yet.
Check your local Japanese or Korean communities or social pages, there's likely someone selling small plants for a reasonable price. I can supply you seeds if you're interested (I'm in WA).
Germinating shiso seeds
The seeds are tiny, less than a millimetre. Think poppy seed size. They're quite hardy and long lasting though. I've stored some for many years and they germinated fine. Because they're so small, they just need sprinkling across the top of the soil and a very light cover (if any) with seedling mix.
Watering the seed in will mix them enough with the top layer of soil so that you get a strong germination rate. I've found the green shiso germinates so much more consistently than the red. They can be germinated in seedling containers and also on silicone mats in a humid container / room using a light water spray or bath.
Once you get one plant to seed, you'll have shiso for life. They're as hardy as basil and if you leave them in the garden you'll find shiso popping up all over the place.
Let's talk about shade and light
Shiso plants require plenty of sunlight to grow and thrive. Make sure to plant them in a location that receives at least 6-8 hours of mild sunlight per day. The Australian summer sun is too harsh for these plants without a giving them a little TLC.
If you plan to have them out in the mid-summer sun, they need to be well established (well rooted mature plants), have a constant low level of moisture around the roots (deep pot) and some respite from the afternoon light.
I've had shiso survive out in the summer sun using the combination of environmental factors above. Those plants are still surviving today even though they got some crispy leaf edges. They didn't receive full afternoon sun, I think that saved them.
From my experience, shiso grown under shade (verandah) will produce the best, lush and soft leaves. The harsh aussie sun hardens the leaves up and crisps the edges. They also grow smaller and have less flavour.
If you are growing shiso indoors, consider using grow lights to provide sufficient light for the plants.
Ensure good drainage
Shiso plants prefer well-draining soil to prevent water logging, which can lead to root rot. Add heaps of organic matter such as compost to improve soil drainage. Plant in raised beds or containers with drainage holes to ensure proper drainage.
They have a fine root system and so need a some sand to help with nutrient and water transfer. I found that a thin layer of moisture-holding mulch in the base of the pot or bed really helped make them resilient. So when you plant out, put in some mulch first, soil and mulch again.
Pests
Just like some other herbs, snails and slugs love a bit of shiso. You will likely need some kind of snail repellant. The main enemy however for us in Australia, is the cabbage white butterfly - or its caterpillar larvae. I've found that a net is necessary when the butterflies are breeding. It's the easiest way to keep them away.
Ants also tend to like the sand around the root system.
Harvesting your shiso
Harvesting needs to be done delicately. Shiso don't get as woody as basil does and so pulling on the leaves too hard will uproot the plant. I use the method the pickers use in Japan because I don't need a huge volume, and that is to pinch the leaves off with the thumb and forefinger nail. Scissors also make it easy!
Shiso plants benefit from leaf harvesting. You'll notice as the plants get taller, the lower leaves will start to brown off and drop. They're not receiving enough light and will not grow any bigger.
It's best to regularly harvest from the base up, even if you don't eat them. Pinch off any larger leaves and it will help reduce disease, provide more air flow and keep pests away.
Drying the leaves
Shiso leaves can be dried in the same way as many herbs. Just put them out to air dry, use the oven or dehydrator. I prefer to air dry them. I've tested the oven and even on a very low heat it takes a lot of the flavour away.
Dry them out till crunchy and then smash them up into a sealable jar. Shiso for life. You can sprinkle this into your meat dishes, salads, cocktails, drinks, ice cream - you name it. Think of it as the herb that sits between mint and basil.
Shiso oil
Using a distilling method (check out Shinagawa Distillery's method. He uses lab equipment to distill flavours and oils from organic matter), you can extract the shiso oil quite easily. A very interesting process and something I want to test out at some point. I'd love to do this for citrus fruits.
Anyway, there is a lot of oil in shiso and it is commercially harvested and sold in bottles for cooking and other things, particularly so in Korea.
Shiso recipes
At this point I haven't documented any shiso recipes on this blog, but will add them as we go. Try shiso gelato if you get a chance. I mix it with coconut, banana and a little honey, it's sooo good in summer.
Restart the grow process
Your shiso plants will go to seed if you don't pinch the flower spikes off. So if you maintain the right conditions, white flowers will appear very similar to basil flowers. Let the flower spikes dry out and harvest the seed for planting again!
Download my phone wallpaper for free - Shiso Dreams:
I'll keep adding to this as I learn more. Leave a comment and let me know if this has been useful.
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