Gadenin日本語Get the appThe shape of the season
This is a one-sowing crop. Unlike lettuce or rocket, there is no point in successional sowings, because a single stand cut repeatedly will produce from midsummer until the cold arrives. The whole season is therefore four phases: get it up in warm soil, build a bushy plant, cut it repeatedly through the heat, and manage the flowering at the end.
The calendar is driven by soil and night temperatures rather than by dates, which makes it portable between hemispheres and between climates. Warm soil starts it, shortening days trigger flowering, and the first cold nights end it.
In a long hot summer you can expect four or five hard cuts from a stand. In a marginal climate with a short warm window you may get two, which is still worth having for a crop occupying the bed during the weeks when little else leafy will grow.
| Phase | Trigger | Main jobs |
|---|---|---|
| Sowing | Soil above 68F (20C), preferably 77F (25C) | Soak seed, sow shallow, keep the surface damp |
| Establishment | Two to four true leaves | Thin, cover against flea beetles, weed |
| Building the bush | Plant at twelve inches (30 cm) | Top the main stem, mulch, start feeding |
| Cut and come again | Peak heat | Cut every ten to fourteen days, feed after each cut |
| Flowering | Days shortening in late summer | Pinch off every flower bud twice a week |
| Finish | Nights below 50F (10C) | Final harvest, freeze the surplus, clear the bed |
Early season: getting a stand
Everything early is about warmth and moisture. Prepare the bed with a couple of inches (5 cm) of compost, wait until the soil at two inches (5 cm) deep is reliably above 68F (20C), then sow soaked seed a quarter inch (6 mm) deep and keep the surface from drying out until it is up.
Once the seedlings have two true leaves, thin them to four inches (10 cm) for a dense cutting stand or eight to twelve inches (20 to 30 cm) for large branching plants. Keep a floating row cover over the bed until the plants are six inches (15 cm) tall if flea beetles are a problem where you garden.
Mulch once the plants are six inches (15 cm) tall and the soil is thoroughly warm. Mulching earlier than that insulates cold soil and holds the crop back, which is the opposite of what you want at this stage.
Midseason: the cutting months
This is the productive stretch and it runs on a simple loop. Top the plant at twelve inches (30 cm), let the side shoots come, pinch those, and from then on every harvest is also the pruning that drives the next flush.
- Cut every ten to fourteen days In peak heat that is the interval a fed, watered plant can sustain. Cut back to six to eight inches (15 to 20 cm) above the soil, always just above a joint that still carries leaves, so there are buds to break.
- Feed within a day of every cut A nitrogen-leaning liquid feed straight after cutting is what keeps leaf size up across four or five successive harvests. An unfed stand gives progressively smaller, tougher leaves and flowers earlier.
- Water deeply, not lightly Aim for about an inch (25 mm) a week, more in a run above 95F (35C) and daily in containers. A drought check produces thick tough leaves and pushes the plant toward flowering ahead of time.
- Stagger cuts across the row Cut half the plants one week and the rest a fortnight later so you always have something in full leaf. It also spreads the workload, since a hard cut on a whole row produces more greens at once than most households can use fresh.
- Watch for spider mites in dry heat Check leaf undersides weekly during a hot dry run. A hard cut removes most of an infestation in one go, which is why this crop rarely needs anything sprayed on it.
Late season: flowers, pods and clearing up
As the days shorten, small yellow flowers appear in the leaf joints. From the first bud onward, go over the plants twice a week and pinch every flower off. This keeps leaf production running for several extra weeks and, more importantly, stops pods forming among foliage you are harvesting. The seeds and pods of this plant are toxic and only the young leaves and shoot tips are eaten, so keeping pods out of the picking rows is a food-safety job rather than a yield one.
If you want seed for next year, mark one or two plants at the end of the row, stop picking leaves from them entirely, and let their pods dry to brown on the plant. Thresh and clean that seed away from the kitchen and store it in a clearly labeled jar, out of reach of children and pets.
When nights drop below 50F (10C) the crop is finished. Take a final full harvest, blanch and freeze the surplus, then pull the plants, collect any shattered pods off the soil and compost the stems. Note where the row was so you can move it for the next three years, because root-knot nematodes build up under this crop in warm soil.
The three dates worth keeping are the first cut, the first flower bud and the final harvest. Flowering is driven largely by daylength, so that middle date barely moves from year to year on your site and it lets you plan the end of the season instead of being caught out by it.