Succession Planting Calculator

Calculate staggered sowing dates and harvest windows for a continuous vegetable supply. Computes batch sowing intervals, harvest spans, and final safe fall planting cutoff dates.

Method reviewed by Plant Calculator Team·Updated August 2026

How this is worked out

Batch Sow Date_n = First Sow Date + (n - 1) × Interval   ·   Final Fall Cutoff = First Fall Frost - (DTM + Harvest Window + 14-Day Buffer)

Where DTM is Days to Maturity. The 14-day fall buffer accounts for decelerated autumn growth caused by shortening photoperiods (Persephone period).

Assumptions

Staggering small sowings every 7 to 21 days prevents overwhelming harvest gluts and ensures continuous fresh table produce.

Days to Maturity (DTM) represents average growth duration from direct seeding under optimal spring/summer soil temperatures.

Autumn plant growth slows by 30% to 50% as daily sunlight drops below 10 hours; the 14-day Persephone buffer prevents frost kill before harvest.

Harvest window duration varies by crop durability (e.g. 7 days for radishes, 21 days for bush beans, 35 days for kale).

Succession planting strategy: continuous harvests & autumn cutoff dates

The most common disappointment in kitchen gardening is the "feast or famine" harvest cycle: harvesting 40 heads of romaine lettuce in a single week in June, followed by completely empty salad beds for the rest of July and August. Succession planting solves this dilemma by calculating precise, staggered planting dates matched to crop maturity rates and regional frost windows.

The Three Main Succession Planting Methods

1. Staggered Intervals of the Same Crop: Sowing a small bed section (e.g. 5 to 10 row-feet) of a single variety every 7 to 14 days throughout the season. When Batch #1 finishes its harvest window, Batch #2 reaches peak maturity.
2. Simultaneous Sowing of Varied Maturity Cultivars: Planting an early-season variety (50 DTM), a mid-season variety (70 DTM), and a late-season variety (90 DTM) on the exact same day. The crops naturally mature sequentially over several months.
3. Crop-After-Crop Seasonal Rotation: Following early-spring cold-tolerant crops (radishes, spinach, peas) with mid-summer heat lovers (bush beans, zucchini), followed by late-summer fall brassicas (kale, rutabagas, garlic).

Succession Planting Interval Guide

Recommended Succession Intervals and Harvest Windows
Crop	Days to Maturity (DTM)	Sowing Interval	Harvest Window Duration
Radish	22 – 28 Days	Every 7 Days	7 – 10 Days (becomes pithy)
Leaf Lettuce & Arugula	35 – 45 Days	Every 10 – 14 Days	14 – 21 Days (bolts in heat)
Bush Green Beans	50 – 60 Days	Every 14 – 21 Days	14 – 18 Days
Sweet Corn	70 – 85 Days	Every 14 Days	7 – 10 Days
Carrots & Beets	65 – 75 Days	Every 21 Days	30+ Days (stores in soil)
Cilantro & Dill	40 – 50 Days	Every 14 Days	10 – 14 Days

How to Calculate the Final Fall Cutoff Date

Final Fall Sowing Date = First Autumn Frost Date - DTM - Harvest Window - 14 Days (Fall Buffer)

The 14-day Fall Buffer accounts for the "Persephone Period" (day length falling below 10 hours and cooler soil temperatures that slow growth rates by 25% to 40%).

Three Worked Succession Sowing Examples

1. Bush Green Beans (55 DTM, Zone 6: April 25 to October 15 Frost)

First sowing: April 25 → Harvest starts: June 19. Harvest window = 14 days. Sowing interval = 14 days. Final Fall Cutoff = Oct 15 - 55 DTM - 14-day harvest - 14-day buffer = July 24. Total of 7 distinct batches sown every 2 weeks (last sowing July 18), providing a continuous 98-day fresh bean harvest from June 19 through late September.

2. Gourmet Salad Greens (40 DTM, March 20 to November 1 Frost)

Sowing interval: 10 days. Harvest window = 14 days. Final Cutoff = Nov 1 - 40 DTM - 14 - 14 = August 25. Results in 16 continuous salad batches.

3. Sweet Corn (75 DTM, May 15 to October 1 Frost)

Sowing interval: 14 days. Harvest window = 10 days. Final Cutoff = Oct 1 - 75 DTM - 10 - 14 = June 24. Allows 3 continuous sweet corn blocks (May 15, May 29, June 12), ensuring fresh sweet corn from July 29 through early September.

Common Succession Planting Mistakes

Forgetting the Autumn Fall Factor: Planting on August 15 based on catalog 50 DTM without adding 14 days of buffer means the crop runs out of sunlight and heat units in October, leaving unripened pods when frost strikes.
Sowing too much seed in each batch: Sowing 30 row-feet of lettuce at once produces 60 lbs of greens that spoil before a family can eat them. Sow small 3-to-5 foot rows frequently.
Neglecting summer seed bed moisture: Mid-summer July sowings encounter hot, dry soil crusts. Water newly sown succession seeds daily under shade cloth until germination occurs.

Plan seasonal schedules and seed quantities with our Planting Calendar, Seed Quantity Calculator, and Crop Rotation Calculator.

Common questions

What is succession planting?

Succession planting is the horticultural practice of sowing small batches of seeds at regular intervals (every 7 to 21 days) throughout the growing season. This prevents single massive harvest gluts and ensures a steady, continuous weekly supply of fresh produce from spring through autumn.

How is the final safe fall planting cutoff date calculated?

The final fall cutoff date is calculated by working backward from your first expected autumn frost date: Final Sowing Date = Frost Date - Days to Maturity (DTM) - Harvest Window Duration - 14-day Autumn "Fall Factor" (to account for slowing plant growth under shorter day lengths).

Which vegetables are best suited for staggered succession sowing?

Fast-maturing vegetables and crops with short harvest windows benefit most from succession planting: radishes (sow every 7 days), leaf lettuce and arugula (every 10 days), bush green beans (every 14 days), sweet corn (every 14 days), and cilantro/dill (every 14 days).

What is the difference between same-crop succession and crop-after-crop succession?

Same-crop succession staggers repeat sowings of the same vegetable (e.g. planting 10 feet of bush beans every 2 weeks). Crop-after-crop succession plants a completely different vegetable immediately after the first crop is harvested (e.g. planting summer bush beans into the bed where spring spinach was just harvested).

Succession Crop & Season Dates