My shiso has just started flowering as per photo, and considering how tricky it can be to germinate Shiso seeds (you have to put them in the fridge for a week etc) this year I have maybe a dozen or more Shiso plants which are all self seeded! So if you happen to ever grow it I highly reccomend letting it go to seed & just leave it in your garden, as it means next Spring you will be rewarded with lots of self seeded plants & no need to germinate any new ones at all! (Shiso green = Perilla = delicious with sushi & sashimi, great in salads etc… you can easily buy it fresh in supermarkets in Japan, but I’ve never seen it for sale in NZ… oishi!)