Perilla Seed Crop Calendar: From Sowing to Clearing the Bed

The year at a glance

Perilla runs on a short, intense season with one immovable event in it. Everything before flowering is about building as many shoot tips as possible; everything after it happens fast and has to be watched every few days. The table below is the whole crop in one view.

The seasons here are written for a temperate garden and read the same in either hemisphere. Substitute your own frost dates and your own memory of when the nights start drawing in, and the sequence holds.

Spring: buy yourself growing time

The whole spring job is to get a well-rooted, already-branching plant into the ground as early as the weather allows. Because flowering is triggered by daylength rather than by the plant's age, every week you gain in spring turns directly into extra shoots, and extra shoots are extra spikes. There is no way to make up for it later.

Start the seed indoors on a surface sowing at 68 to 77F (20 to 25C), and expect ten to twenty days. Pot the seedlings on individually once they have two pairs of true leaves. Harden off over a week and plant out only when night temperatures hold above 54F (12C); perilla checks badly in cold soil and a plant that sits sulking for three weeks has lost the advantage you were buying.

1. Prepare the bed before you plant Work in compost and a general-purpose granular feed a fortnight ahead. Perilla wants moisture-retentive soil that still drains, and full sun to light afternoon shade.
2. Plant into warm soil Wait for 59F (15C) at planting depth. Covering the bed with row cover or a cloche for a week beforehand brings it forward and is worth doing in a cold spring.
3. First pinch a week after planting out Give the plant seven days to get roots moving, then take out the growing tip above the second or third leaf pair once four pairs have opened.

Do not put out plants that have gone tall and pale on a windowsill. Pinch them hard at planting; a stretched seedling never makes a strong framework and it flowers on the same night as everything else regardless.

Summer: build the framework, then stop

Early summer is the productive stretch. Pinch each new shoot at three or four leaf pairs, feed a balanced liquid feed every two to three weeks, and water deeply rather than often. A plant that is growing hard through this period doubles its shoot count roughly every two to three weeks.

Midsummer brings the two deadlines that decide the crop. Six weeks before your usual flowering time, stop pinching, because any shoot started after that is too small to carry a decent spike. At the same time, stop the nitrogen feed and put the canes and string in while the plant is still light enough to work around.

High summer is otherwise mostly about water. Perilla wilts theatrically in heat; check the soil before reaching for the hose, and mulch with two inches (5 cm) of compost to hold moisture and keep the roots cooler.

Write down the date of the last pinch and the date the first spike appeared. The gap between them is the number you will use to set next year's deadline, and in the same garden it barely changes.

Late summer to autumn: the harvest happens fast

As the nights lengthen, tight green columns appear at the end of every shoot within a few days of each other across the whole planting. From that moment the crop is on a two or three day inspection cycle, because the three picking stages, tight bud, first flowers open, and green seed, follow one another in barely two weeks and each lasts only a few days.

Once the lower seed has hardened and the spikes begin browning, switch from picking to bagging. Ripe perilla seed shatters at a touch, so every cut is made with a bag or a tray held under the head. Hang the bags somewhere dry and airy for a fortnight, then thresh and winnow.

Reduce watering through this whole period. Wet spikes in a still, humid autumn go moldy from the inside, and a moldy head cannot be saved. Strip the yellowing lower leaves at the same time to move air through the plant.

1. Walk the row every two to three days Take a container with you. Deciding to come back later is how a whole planting goes past the bud stage in one go.
2. Pick over the plant, not through it Spikes at the top and on the sunny side run three or four days ahead of those lower and shaded. Taking the ready ones each visit stretches every window.
3. Bag before you cut, every time From the green seed stage onward, hold the bag or tray under the head first and cut into it. Never carry a ripe spike across the garden in the open.

Clearing up, and keeping it where you put it

The season ends with a job that is easy to skip and expensive to skip. Anything left standing sheds thousands of seeds exactly where it stands. Perilla self-seeds heavily, and in parts of North America it has escaped gardens into pasture and woodland edge, where it is treated as invasive and is toxic to grazing livestock. Cutting the remainder down and taking it away is part of growing the crop.

Cut the plants while the heads are brown but before they shed freely. Bag the heads at the moment of cutting, carry the bags rather than the plants, and bin anything moldy instead of composting it. A cold compost pile will not kill the seed and simply moves the problem to wherever you spread it.

Then plan for the volunteers, because there will be some however careful you were. Go over the bed the following spring while the seedlings still have only their two rounded seed leaves; one pass with a sharp hoe on a dry day clears the lot. Left until they have four true leaves and a taproot, they come out one at a time by hand.

Note in your records which plants you cleared and where volunteers came up. It identifies the plant that shattered before you got to it, and it tells you which corner of the bed to check first the following spring.