Field guide · Succession
Planting Salad Greens in Succession: Sowing Intervals for a Weekly Harvest
Salad greens do not wait. A full 50-foot bed of butterhead cut on one Thursday is 80 pounds you cannot sell by Saturday. Succession planting is the clock that turns that bed into 15–20 pounds a week for a month.
The interval is set by days to harvest and by how fast the crop bolts in your heat, not by a generic "sow every two weeks."
Bed math first
On a 30-inch bed you can run:
- Baby mix, broadcast or 6-row seeder: harvest the whole surface as cut-and-come-again.
- Head lettuce: 3 rows, 9–10 inches between rows, 8–10 inches in-row. About 180–210 heads per 50-foot bed.
- Spinach: 4 rows, 6–7 inches apart.
One 50-foot baby-mix bed yields 25–40 lb on the first cut at 4–5 inches, then 15–25 lb on a second cut 10–14 days later if nights stay under 70°F. After two cuts, flip it.
Intervals that match the crop
| CROP | DAYS TO FIRST CUT (COOL WEATHER, 50–65°F SOIL) | SOW OR TRANSPLANT EVERY | BEDS TO KEEP ONE CASE/WEEK | NOTES |
|---|---|---|---|---|
| Baby lettuce mix | 28–35 | 7 days | 4 beds in rotation | Fastest clock; summer heat shortens quality window |
| Head lettuce (transplant) | 45–55 from transplant | 7–10 days | 5–6 beds | Seed in 1.5 in blocks 3–4 weeks before setting |
| Spinach | 35–45 | 10 days | 4 beds | Stops germinating well above 75°F soil |
| Arugula | 21–28 | 7 days | 3 beds | Bolts fast; do not leave a third cut |
| Mustard / mizuna | 21–28 | 7 days | 3 beds | Same as arugula |
| Kale for salad (baby) | 30–35 | 10 days | 3 beds | Tougher in heat than lettuce |
"One case/week" here means about 3 lbs packed as mix or 12–16 heads. Scale the bed count to your actual orders.
A 4-bed baby-mix rotation
Label the beds W1, W2, W3, W4.
- Monday week 1: sow W1.
- Monday week 2: sow W2. First cut W1 if it is at 4 inches; if not, wait 3–4 days.
- Monday week 3: sow W3. Cut W1 second time or flip if quality dropped. First cut W2.
- Monday week 4: sow W4. Continue.
- Monday week 5: clear W1, re-prep (stale seedbed if chickweed is moving), sow W1 again.
In spring at 55°F soil, stretch the interval to 10 days. In late spring at 70°F days, tighten to 5–6 days and switch to heat-tolerant romaine and oakleaf. Butterhead in 85°F weather is a donation to the compost pile.
Transplant vs direct seed
Head lettuce earns more per bed if you transplant. Seed 1.5-inch soil blocks or 128s every 7 days, 40–50 cells per sowing if you sell 40 heads a week. Set them at 3–4 true leaves, 28–35 days from seed.
Direct-sow heads only if your stale seedbed is clean. Lettuce seed sitting 10 days next to germinating pigweed loses.
Spinach prefers direct seed, 1/2 inch deep, 8–10 seeds per foot in each row. Soak seed 8 hours if soil is over 70°F; even then germination is a gamble. Have a heat-standby (New Zealand spinach or malabar) or just stop spinach in June.
Harvest rules that keep the interval honest
Cut baby mix at 3–5 inches, in the morning, into totes in the shade. First cut leaves a 1-inch stub. Second cut if the stand is clean. Third cut is usually bitter.
Heads: cut at full cupping, cool to 34–36°F within 60 minutes. A head that sat in the sun for 20 minutes after harvest loses a day of shelf life.
If a sowing is 5 days late because rain closed the bed, do not "catch up" by sowing a double bed the same day unless you have a double market. Sow the missed amount and accept a thin week. Two full beds arriving together is how greens dump prices.
Heat plan for June
When afternoon highs hold above 85°F, stop butterhead. Keep the 7-day clock but switch the sowing to romaine, oakleaf, and a 20% arugula / 80% lettuce mix. Shade cloth at 30% over the bed from 11 a.m. to 4 p.m. cuts bitterness more than another gallon of water. Pull the cloth 3 days before harvest so the leaves do not stay wet overnight.
Record first-cut date next to the sow date. If baby mix is hitting 4 inches at day 24 instead of day 30, tighten the next interval by 3 days. The bed is telling you the weather changed. The calendar is not the crop.
Key numbers
- Baby mix: sow every 7 days in cool weather, 5–6 days as heat rises.
- Head lettuce transplants: every 7–10 days; 180–210 heads per 30 in × 50 ft bed.
- First cut baby mix: 28–35 days, 25–40 lb per 50 ft bed.
- Two cuts max, then flip.
- Four beds in rotation cover a weekly baby-mix case; add beds to match orders, not hope.