It stands 15 cm tall for most of the summer. In August, it blooms and its stem elongates rapidly. The plant reaches a height of approximately 1 m before being killed by frost. Photoperiod Perilla has been used by plant physiologists to investigate floral induction. Long nights induce flowering, but different accessions have different critical night lengths.
Plants become photosensitive at the forth leaf pair stage.
Flowering starts 18 to 20 days after the start of long nights. After 30 long nights, plants will bloom until they die, regardless of subsequent daylength. The seeds can be planted one cm deep after danger of frost. One of the greatest difficulties in perilla cultivation is the limited seed viability in storage. At room temperature, the seeds can die in less than a year.