What the worksheet calculates
Indoor start = spring frost date minus your chosen lead time. Outdoor date = spring frost date plus your chosen delay. Latest autumn sowing scenario = autumn frost date minus days to maturity and your chosen growth buffer.
The default numbers are editable teaching inputs. They are not a recommended schedule for every crop. Weather, soil temperature, varieties, transplanting, daylight, protection and local growing conditions can change the appropriate date. A frost-free climate needs its own locally suitable planting windows.
Use the result with local guidance
- Confirm the local frost-date assumptions and their probability with a weather or Extension source.
- Use the crop’s actual sowing instructions and clarify how days to maturity are counted.
- Check soil and weather conditions before planting.
- Label dates as scenarios and record the actual outcome for next season.