Gadenin日本語Get the appSow shallow and keep the surface damp
Loose leaf lettuce seed needs light to germinate, so it goes almost on the surface. An eighth of an inch (3 mm) of sifted compost is the whole covering. Anything deeper and the shoot exhausts itself before it reaches daylight, which is why deep-sown rows come up thin and staggered rather than not at all.
The trade-off is that shallow seed dries out fast. A surface that dries once between watering and emergence will cost you a third of the row. Water the drill before you sow rather than after, so the moisture sits under the seed instead of washing it sideways, then keep the top half inch damp until the first true leaf appears.
- Water the drill first Run water into the open drill and let it soak in. Sowing into damp soil and covering dry means you do not have to water over the seed at all for the first day.
- Sow along a band, not a line Scatter seed along a band two inches (5 cm) wide rather than a single line. Loose leaf is picked leaf by leaf, so a band gives more picking surface per foot of row than a precise line does.
- Sift the cover Sift compost or fine vermiculite over the band. Vermiculite stays visibly damp, so you can see when the surface has dried instead of guessing.
- Shade until emergence Lay row cover or a board over the band and lift it the morning the first shoots show. Left on any longer the seedlings stretch and fall over.
Soil temperature decides how much of the packet works
Loose leaf types germinate across a wider band than heading lettuce, but they still go dormant in heat. The useful range is 45 to 70F (7 to 21C), with the fastest and most even emergence around 60F (16C). Above 80F (27C) germination drops off sharply, and it is the soil under the surface that counts, not the air.
This is why the same packet gives ninety percent in cool weather and forty percent in midsummer. It is not old seed. In hot weather, sow in the evening into soil you have watered in the afternoon, and shade the band for the first three days.
| Soil temperature | Days to emerge | What you will see | Adjustment |
|---|---|---|---|
| 45F (7C) | 10 to 14 | Slow but even | Sow a little thicker and be patient |
| 55 to 65F (13 to 18C) | 4 to 6 | Even, near full stand | None needed |
| 75F (24C) | 5 to 8 | Gappy, uneven heights | Sow in the evening, shade three days |
| Above 80F (27C) | Erratic or none | Scattered singles only | Chill seed two days before sowing |
To chill seed, soak it for six hours, drain, wrap in damp paper and hold it in the fridge for two days. Sow the moment a white root tip shows: longer than a millimeter and the roots snap during handling.
Succession sowing is the whole point
A heading lettuce is a single harvest, so you space out sowings to space out heads. Loose leaf is different: one sowing gives you three or four cuts over a month or more, and then declines as the plants get tough and start to bolt. Sowing a short band every two to three weeks keeps you permanently in the middle of that productive window rather than at the end of it.
In practice a three foot (1 m) band feeds two people for a fortnight of picking. Sow that much every two weeks in spring and autumn, and stretch the interval to three weeks in the cool of early spring when growth is slow. Stop sowing about six weeks before your first hard frost, or before the heat of high summer, whichever your season reaches first.
| Season | Sowing interval | Where to sow | Expected cuts per sowing |
|---|---|---|---|
| Early spring | Every 3 weeks | Under cover or cloche | 3 to 4 |
| Late spring | Every 2 weeks | Open ground, full sun | 3 to 4 |
| Summer | Every 2 weeks, small batches | Afternoon shade | 2, then bolting |
| Early autumn | Every 2 weeks | Open ground | 4 or more |
Thinning, and what baby leaf changes
How hard you thin depends on the size of leaf you want. For full-size loose leaf plants that you pick from repeatedly, thin to six inches (15 cm) apart once the plants have two true leaves. For baby leaf, sown as a dense band and cut whole with scissors, you do not thin at all; the crowding is deliberate and keeps the leaves small and upright.
Do not throw the thinnings away. Loose leaf thinnings at the two to three leaf stage are the best salad the bed will produce all season, and pulling them is the first harvest rather than a chore. Pinch them out at soil level instead of yanking, so the neighbors' roots stay put.
| Growing style | Final spacing | First pick | How you cut |
|---|---|---|---|
| Baby leaf | No thinning, dense band | 21 to 28 days | Scissors, whole band, one inch above soil |
| Cut-and-come-again plants | 6 inches (15 cm) | 35 to 45 days | Outer leaves, a few per plant |
| Full plants for one harvest | 10 inches (25 cm) | 50 to 60 days | Whole plant at the base |
What to write down at sowing
The single most useful record for loose leaf lettuce is the sowing date against the date of the first cut, because that gap tells you how far ahead to sow next year in the same conditions. It varies from three weeks in warm weather to seven in early spring, and memory always compresses it.
Note which end of the bed each batch went into as well. By the third succession sowing every band looks alike, and knowing the order tells you which one to cut first and which to leave. Record the soil temperature or at least the weather in the sowing week if you can, so a poor stand can be explained later rather than blamed on the seed.
Keep a note of how many cuts each sowing gave before turning bitter. Two consecutive years of that number tells you exactly how many bands you need in the ground at once.