---
title: "Succession Planting Chart: Calculate Exact Sow Dates Before Frost Cuts Your Season Short"
canonical: "https://theyieldgrid.com/succession-planting-chart/"
model_id: "tyg-858"
model_version: "1.0.0"
last_reviewed: "2026-04-27T19:47:06"
reviewed_by: "Umer Hayiat"
---

# Succession Planting Chart: Calculate Exact Sow Dates Before Frost Cuts Your Season Short

> Canonical calculator: [https://theyieldgrid.com/succession-planting-chart/](https://theyieldgrid.com/succession-planting-chart/)

## What this calculator does

Home - Free Gardening Calculators & Tools - Succession Planting Chart: Calculate Exact Sow Dates Before Frost Cuts Your Season Short The gap between “I want continuous harvests” and “I actually get them” almost always comes down to one number: the interval. Plant too far apart and you get feast-then-famine. Plant too close together and you overwhelm your kitchen, your storage, and your soil at the same time. To add pressure, every succession that starts too late in the season hits a hard biological wall when frost arrives, voiding all the labor that went into it. Tracking your growing degree days can help you understand how temperature accumulation affects your true season length before you even set a first sow date.

## Inputs

| Input | ID | Type | Unit | Range or choices | Required |
|---|---|---|---|---|---|
| First Sow Date | `spi_first_sow` | date |  |  | Yes |
| First Frost Date (optional) | `spi_frost_date` | date |  |  | No |
| Interval (Weeks) | `spi_interval` | number |  | 1 to 52 | Yes |
| Number of Plantings | `spi_num_plantings` | number |  | 2 to 52 | Yes |

## Outputs

| Output ID | Default state |
|---|---|
| `spi_first_sow_err` |  |
| `spi_frost_date_err` |  |
| `spi_interval_err` |  |
| `spi_num_plantings_err` |  |
| `spi_results` | Succession Planting Chart Full Planting Schedule Planting # Sow Date Days from First Status How This Calculator Works Formula: Each planting date is calculated by adding n × 7 days to your First Sow Date, where n is the planting number (0, 1, 2 …). Date[n] = First Sow Date + (n × Interval × 7 days) Example: First Sow = April 1, Interval = 2 weeks, 4 plantings: Planting 1: April 1 + (0 × 14) = April 1 Planting 2: April 1 + (1 × 14) = April 15 Planting 3: April 1 + (2 × 14) = April 29 Planting 4: |
| `spi_out_primary` |  |
| `spi_warn_box` |  |

## Formula and method

The tool adds exact weekly intervals to your first sow date and halts the schedule at your frost boundary to keep every planting safe. Show the calculation steps Step 1: Establish the anchor date. The First Sow Date is assigned to batch number 0 (the first planting). It is the fixed reference point for every subsequent date. Step 2: Convert the interval to days. The interval you enter in weeks is multiplied by 7 to produce days. A 2-week interval becomes 14 days. A 3-week interval becomes 21 days. Step 3: Apply the formula for each planting. Date[n] = First Sow Date + (n × Interval_weeks × 7) Where n starts at 0 for the first planting and increments by 1 for each successive batch. For 5 plantings, n runs from 0 to 4. Step 4: Check each date against the frost boundary. If a frost date is entered, the calculator compares each computed date to it. The moment a computed date equals or exceeds the frost date, that planting receives a “Past Frost” status and the loop stops. Rounding rule: Interval values are rounded to the nearest whole week. There are no fractional days in the output. Unit note: All calculations are in calendar days. No daylight saving adjustments, leap day corrections, or timezone offsets are applied. For schedules spanning late February, verify manually if your region observes leap years. Assumptions and Limits The tool assumes a fixed interval between every planting. Variable-interval schedules (for example, shortening the interval as summer approaches to compensate for faster growth) require manual calculation or separate runs. Frost dates are treated as hard calendar stops. The tool does not know whether a specific crop can tolerate frost; it only checks whether the sow date precedes the frost date. Days-to-maturity is not included in the formula. A planting scheduled before frost may still fail to produce a harvest if the crop cannot mature in the remaining window. This is the most common planning oversight this tool cannot catch on its own. The maximum supported range is 52 plantings at 52-week intervals, equivalent to a 52-year schedule. For practical garden use, keep the number of plantings under 12 for any single season. All dates are interpreted in the local calendar. The tool does not account for hemispheric differences in growing seasons. Interval inputs are restricted to whole-week values (1 to 52). Sub-week scheduling requires a different approach and is outside the scope of this tool. If a frost date is set to the same day as the First Sow Date or earlier, the calculator will flag an error. At least one day must separate the two dates.

## Verified worked examples

### Example 1: Spring Lettuce with a Two-Week Interval

First Sow Date: April 1 Interval: 2 weeks Number of Plantings: 5 Frost Date: none entered Result: 5 scheduled plantings. Dates: April 1, April 15, April 29, May 13, May 27. Total schedule span: 56 days (8 weeks). This is a textbook spring lettuce run. Each batch is separated by 14 days. The last sow date falls on May 27, which for most temperate zones is well ahead of summer heat that would cause bolting. The tool confirms all 5 are scheduled because no frost date was entered.

### Example 2: Summer Beans with a Three-Week Interval and a Fall Frost Check

First Sow Date: June 1 Interval: 3 weeks Number of Plantings: 4 Frost Date: October 1 Result: 4 scheduled plantings. Dates: June 1 (+0 days), June 22 (+21 days), July 13 (+42 days), August 3 (+63 days). All four fall before October 1. Total span: 63 days. August 3 is the last sow date. For a bush bean variety with 55 days to maturity, that batch would be ready around September 27, just inside the October 1 frost date. This is a case where the succession planting chart passes the frost check numerically, but the user must still verify days-to-maturity separately.

### Example 3: Fall Kale Succession Stopped by Frost

First Sow Date: August 1 Interval: 2 weeks Number of Plantings: 7 Frost Date: October 15 Result: 6 scheduled plantings. Dates: Aug 1, Aug 15, Aug 29, Sep 12, Sep 26, Oct 10. The 7th batch (Oct 24 = August 1 + 84 days) equals or exceeds October 15 and is flagged as “Past Frost.” The calculator removes it and stops the schedule. This is the frost safety check working as intended. Without the October 15 entry, the tool would have shown all 7 batches, the last of which would never survive to harvest. The 6 confirmed plantings give a total schedule span of 70 days.

## Assumptions

The tool adds exact weekly intervals to your first sow date and halts the schedule at your frost boundary to keep every planting safe. Show the calculation steps Step 1: Establish the anchor date. The First Sow Date is assigned to batch number 0 (the first planting). It is the fixed reference point for every subsequent date. Step 2: Convert the interval to days. The interval you enter in weeks is multiplied by 7 to produce days. A 2-week interval becomes 14 days. A 3-week interval becomes 21 days. Step 3: Apply the formula for each planting. Date[n] = First Sow Date + (n × Interval_weeks × 7) Where n starts at 0 for the first planting and increments by 1 for each successive batch. For 5 plantings, n runs from 0 to 4. Step 4: Check each date against the frost boundary. If a frost date is entered, the calculator compares each computed date to it. The moment a computed date equals or exceeds the frost date, that planting receives a “Past Frost” status and the loop stops. Rounding rule: Interval values are rounded to the nearest whole week. There are no fractional days in the output. Unit note: All calculations are in calendar days. No daylight saving adjustments, leap day corrections, or timezone offsets are applied. For schedules spanning late February, verify manually if your region observes leap years. Assumptions and Limits The tool assumes a fixed interval between every planting. Variable-interval schedules (for example, shortening the interval as summer approaches to compensate for faster growth) require manual calculation or separate runs. Frost dates are treated as hard calendar stops. The tool does not know whether a specific crop can tolerate frost; it only checks whether the sow date precedes the frost date. Days-to-maturity is not included in the formula. A planting scheduled before frost may still fail to produce a harvest if the crop cannot mature in the remaining window. This is the most common planning oversight this tool cannot catch on its own. The maximum supported range is 52 plantings at 52-week intervals, equivalent to a 52-year schedule. For practical garden use, keep the number of plantings under 12 for any single season. All dates are interpreted in the local calendar. The tool does not account for hemispheric differences in growing seasons. Interval inputs are restricted to whole-week values (1 to 52). Sub-week scheduling requires a different approach and is outside the scope of this tool. If a frost date is set to the same day as the First Sow Date or earlier, the calculator will flag an error. At least one day must separate the two dates. The tool assumes a fixed interval between every planting. Variable-interval schedules (for example, shortening the interval as summer approaches to compensate for faster growth) require manual calculation or separate runs. Frost dates are treated as hard calendar stops. The tool does not know whether a specific crop can tolerate frost; it only checks whether the sow date precedes the frost date. Days-to-maturity is not included in the formula. A planting scheduled before frost may still fail to produce a harvest if the crop cannot mature in the remaining window. This is the most common planning oversight this tool cannot catch on its own. The maximum supported range is 52 plantings at 52-week intervals, equivalent to a 52-year schedule. For practical garden use, keep the number of plantings under 12 for any single season. All dates are interpreted in the local calendar. The tool does not account for hemispheric differences in growing seasons. Interval inputs are restricted to whole-week values (1 to 52). Sub-week scheduling requires a different approach and is outside the scope of this tool. If a frost date is set to the same day as the First Sow Date or earlier, the calculator will flag an error. At least one day must separate the two dates. Critical Warnings Do not rely solely on sow date proximity to frost. A planting that sows two weeks before frost does not have two weeks to mature. It has two weeks before frost kills it, regardless of where it is in its growth cycle. Always subtract the crop’s full days-to-maturity from the frost date to find your true last safe sow date. Omitting the frost date input produces an incomplete result for fall planning. The tool will display all requested batches as “Scheduled” when no frost date is entered, even if some dates fall deep into November. That is not a green light; it is an unchecked assumption. A short interval does not equal a continuous harvest. If your interval is shorter than the crop’s productive harvest window, two batches will mature simultaneously rather than in sequence. For crops like lettuce with a short peak window, an interval that is too tight defeats the entire purpose of succession planting. The “Past Frost” stop is per-batch, not per-plant. Removing a late batch from the chart does not extend or accelerate the batches before it. Each batch is independent. Minimum Standards Set your interval to be at least as long as the crop’s peak harvest window. For most lettuces, that window is 10 to 14 days; for beans, it is 7 to 10 days. An interval shorter than that means two batches are ready at the same time. For fall successions, identify your last safe sow date independently before entering data. Subtract the crop’s days-to-maturity from the frost date. That date, not the frost date itself, is your true ceiling for any succession batch. Run the calculator at least once with the frost date field filled in and once without. The difference between the two outputs shows you how many of your planned batches are genuinely at risk. Competitor Trap: Many succession planting charts available online present a fixed grid of dates by week number without any frost integration. A gardener in zone 5 using a zone 8 chart is likely scheduling three or four batches that will never produce. The frost check built into this tool is the single most important differentiator between a generic date-generator and a genuinely useful succession planting calculator. If your current planning method does not account for frost at the individual-batch level, it is giving you an optimistic schedule that real conditions will override. The vegetable yield calculator can help you model whether your frost-safe batches alone are enough to meet your household needs without the doomed late plantings. For crops that depend heavily on accumulated heat rather than calendar dates alone, pairing your succession chart with a chill hours reference can clarify why identical calendar intervals in spring versus fall can produce very different results. Set your interval to be at least as long as the crop’s peak harvest window. For most lettuces, that window is 10 to 14 days; for beans, it is 7 to 10 days. An interval shorter than that means two batches are ready at the same time. For fall successions, identify your last safe sow date independently before entering data. Subtract the crop’s days-to-maturity from the frost date. That date, not the frost date itself, is your true ceiling for any succession batch. Run the calculator at least once with the frost date field filled in and once without. The difference between the two outputs shows you how many of your planned batches are genuinely at risk. Competitor Trap: Many succession planting charts available online present a fixed grid of dates by week number without any frost integration. A gardener in zone 5 using a zone 8 chart is likely scheduling three or four batches that will never produce. The frost check built into this tool is the single most important differentiator between a generic date-generator and a genuinely useful succession planting calculator. If your current planning method does not account for frost at the individual-batch level, it is giving you an optimistic schedule that real conditions will override. The vegetable yield calculator can help you model whether your frost-safe batches alone are enough to meet your household needs without the doomed late plantings. For crops that depend heavily on accumulated heat rather than calendar dates alone, pairing your succession chart with a chill hours reference can clarify why identical calendar intervals in spring versus fall can produce very different results.

## Limitations and safety

The tool assumes a fixed interval between every planting. Variable-interval schedules (for example, shortening the interval as summer approaches to compensate for faster growth) require manual calculation or separate runs. Frost dates are treated as hard calendar stops. The tool does not know whether a specific crop can tolerate frost; it only checks whether the sow date precedes the frost date. Days-to-maturity is not included in the formula. A planting scheduled before frost may still fail to produce a harvest if the crop cannot mature in the remaining window. This is the most common planning oversight this tool cannot catch on its own. The maximum supported range is 52 plantings at 52-week intervals, equivalent to a 52-year schedule. For practical garden use, keep the number of plantings under 12 for any single season. All dates are interpreted in the local calendar. The tool does not account for hemispheric differences in growing seasons. Interval inputs are restricted to whole-week values (1 to 52). Sub-week scheduling requires a different approach and is outside the scope of this tool. If a frost date is set to the same day as the First Sow Date or earlier, the calculator will flag an error. At least one day must separate the two dates. Critical Warnings Do not rely solely on sow date proximity to frost. A planting that sows two weeks before frost does not have two weeks to mature. It has two weeks before frost kills it, regardless of where it is in its growth cycle. Always subtract the crop’s full days-to-maturity from the frost date to find your true last safe sow date. Omitting the frost date input produces an incomplete result for fall planning. The tool will display all requested batches as “Scheduled” when no frost date is entered, even if some dates fall deep into November. That is not a green light; it is an unchecked assumption. A short interval does not equal a continuous harvest. If your interval is shorter than the crop’s productive harvest window, two batches will mature simultaneously rather than in sequence. For crops like lettuce with a short peak window, an interval that is too tight defeats the entire purpose of succession planting. The “Past Frost” stop is per-batch, not per-plant. Removing a late batch from the chart does not extend or accelerate the batches before it. Each batch is independent. Minimum Standards Set your interval to be at least as long as the crop’s peak harvest window. For most lettuces, that window is 10 to 14 days; for beans, it is 7 to 10 days. An interval shorter than that means two batches are ready at the same time. For fall successions, identify your last safe sow date independently before entering data. Subtract the crop’s days-to-maturity from the frost date. That date, not the frost date itself, is your true ceiling for any succession batch. Run the calculator at least once with the frost date field filled in and once without. The difference between the two outputs shows you how many of your planned batches are genuinely at risk. Competitor Trap: Many succession planting charts available online present a fixed grid of dates by week number without any frost integration. A gardener in zone 5 using a zone 8 chart is likely scheduling three or four batches that will never produce. The frost check built into this tool is the single most important differentiator between a generic date-generator and a genuinely useful succession planting calculator. If your current planning method does not account for frost at the individual-batch level, it is giving you an optimistic schedule that real conditions will override. The vegetable yield calculator can help you model whether your frost-safe batches alone are enough to meet your household needs without the doomed late plantings. For crops that depend heavily on accumulated heat rather than calendar dates alone, pairing your succession chart with a chill hours reference can clarify why identical calendar intervals in spring versus fall can produce very different results.

## Related calculators

- [Calculators & Tools](https://theyieldgrid.com/category/garden-calculators/)
- [growing degree days](https://theyieldgrid.com/growing-degree-days-calculator/)
- [seed packet calculator](https://theyieldgrid.com/seed-packet-calculator/)
- [harvest date calculator](https://theyieldgrid.com/harvest-date-calculator/)
- [vegetable yield calculator](https://theyieldgrid.com/vegetable-yield-calculator/)
- [chill hours reference](https://theyieldgrid.com/chill-hours-calculator/)
- [plant spacing calculator](https://theyieldgrid.com/plant-spacing-calculator/)
- [Prev Previous](https://theyieldgrid.com/wicking-bed-calculator/)
- [Next Next](https://theyieldgrid.com/vpd-calculator-2/)

## Provenance

- Model ID: `tyg-858`
- Model version: `1.0.0`
- Reviewed by: Umer Hayiat
- Page modified: 2026-04-27T19:47:06
- Runtime SHA-256: `84ab23b8baaa851017c8ae3e02dd58623c0d9ed3bf3dd3c0ef31e9300ea09d9f`

This Markdown document is a machine-readable mirror. The canonical interactive calculator is the HTML page linked above.