When to start your seeds indoors
Every variety below carries its own sowing lead time and days to maturity. Enter the average last frost date for your area and the table turns those figures into dates for your season.
Planning next season: sorted by sowing date for next spring, earliest first.
Dates below use a last frost of May 1. Transplant out May 1 – 15, the two weeks after your last frost. Days to maturity are counted from transplanting for every variety below.
Tomatoes
 | Feb 27 – Mar 13 (estimated) Seedlings Mar 6 – 23 | Jul 10 – 24 |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 20 – Aug 3 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 20 – Aug 3 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 12 – 30 | Jul 25 – Aug 8 |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 10 – 24 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 12 – 30 | Jul 25 – Aug 8 |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 15 – 29 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 25 – Aug 8 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 15 – 29 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jun 25 – Jul 9 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 12 – 26 |
 | Mar 6 – 20 (estimated) Seedlings Mar 12 – 30 | Jul 13 – 27 |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 18 – Aug 1 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 25 – Aug 8 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 25 – Aug 8 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 15 – 29 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 20 – Aug 3 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 12 – 30 | Jul 15 – 29 |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 15 – 29 |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 15 – 29 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 25 – Aug 8 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 10 – 24 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 8 – 22 |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 15 – 29 |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 25 – Aug 8 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 12 – 30 | Jul 15 – 29 |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 10 – 24 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 12 – 30 | Jul 20 – Aug 3 |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 12 – 26 |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 10 – 24 |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 15 – 29 |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 20 – Aug 3 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 20 – Aug 3 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 10 – 24 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 20 – Aug 3 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 20 – Aug 3 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 12 – 30 | Jul 20 – Aug 3 |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 20 – Aug 3 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 20 – Aug 3 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jun 29 – Jul 13 |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 2 – 16 |
 | Mar 6 – 20 Seedlings Mar 13 – Apr 3 | Jul 10 – 24 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 20 – Aug 3 |
 | Mar 6 – 20 (estimated) Seedlings Mar 12 – 30 | Jul 25 – Aug 8 |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 25 – Aug 8 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 28 – Aug 11 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 12 – 30 | Jun 25 – Jul 9 |
 | Mar 6 – 20 (estimated) Seedlings Mar 12 – 30 | Jul 25 – Aug 8 |
 | Mar 6 – 20 (estimated) Seedlings Mar 12 – 30 | Jun 28 – Jul 12 |
 | Mar 6 – 20 (estimated) Seedlings Mar 12 – 30 | Jul 20 – Aug 3 |
 | Mar 6 – 20 (estimated) Seedlings Mar 12 – 30 | Jul 20 – Aug 3 |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 25 – Aug 8 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 15 – 29 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 25 – Aug 8 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 10 – 24 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 18 – Aug 1 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 25 – Aug 8 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 12 – 30 | Jun 30 – Jul 14 |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 15 – 29 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 31 – Aug 14 |
 | Mar 6 – 20 (estimated) Seedlings Mar 12 – 30 | Jul 5 – 19 |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 15 – 29 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 20 – Aug 3 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 25 – Aug 8 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 12 – 30 | Jul 12 – 26 |
 | Mar 6 – 20 (estimated) Seedlings Mar 12 – 30 | Jul 20 – Aug 3 |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jun 30 – Jul 14 |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 25 – Aug 8 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 12 – 26 |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jun 30 – Jul 14 |
 | Mar 6 – 20 (estimated) Seedlings Mar 12 – 30 | Jul 18 – Aug 1 |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 15 – 29 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 25 – Aug 8 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 15 – 29 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 15 – 29 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 15 – 29 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 25 – Aug 8 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 12 – 26 |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 20 – Aug 3 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 15 – 29 |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 15 – 29 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 12 – 30 | Jul 10 – 24 |
 | Mar 6 – 20 (estimated) Seedlings Mar 12 – 30 | Jul 25 – Aug 8 |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 25 – Aug 8 (estimated) |
 | Mar 6 – 20 Seedlings Mar 13 – Apr 3 | Jun 30 – Jul 14 (estimated) |
 | Mar 6 – 20 Seedlings Mar 13 – Apr 3 | Jul 18 – Aug 1 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 25 – Aug 8 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 12 – 30 | Jun 28 – Jul 12 |
 | Mar 6 – 20 (estimated) Seedlings Mar 12 – 30 | Jul 10 – 24 |
 | Mar 6 – 20 Seedlings Mar 13 – Apr 3 | Jul 8 – 22 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 20 – Aug 3 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 25 – Aug 8 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 12 – 30 | Jul 15 – 29 |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 18 – Aug 1 |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 15 – 29 |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 15 – 29 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 12 – 26 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 25 – Aug 8 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 20 – Aug 3 |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 20 – Aug 3 |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 15 – 29 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 18 – Aug 1 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jun 25 – Jul 9 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 18 – Aug 1 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 16 – 30 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 20 – Aug 3 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 15 – 29 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 20 – Aug 3 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 28 – Aug 11 |
 | Mar 6 – 20 (estimated) Seedlings Mar 12 – 30 | Jun 22 – Jul 6 |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 25 – Aug 8 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 15 – 29 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 25 – Aug 8 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 25 – Aug 8 |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jun 25 – Jul 9 |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 2 – 16 |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jun 27 – Jul 11 |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 8 – 22 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jun 30 – Jul 14 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 5 – 19 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 15 – 29 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jun 30 – Jul 14 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 10 – 24 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 7 – 21 |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 5 – 19 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 25 – Aug 8 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 15 – 29 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 25 – Aug 8 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 20 – Aug 3 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 30 – Aug 13 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 18 – Aug 1 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 3 | Jul 25 – Aug 8 (estimated) |
Peppers
 | Feb 6 – 20 (estimated) Seedlings Feb 20 – Mar 22 | Aug 29 – Sep 12 (estimated) |
 | Feb 20 – Mar 6 (estimated) Seedlings Feb 27 – Mar 27 | Jul 30 – Aug 13 (estimated) |
 | Feb 20 – Mar 6 (estimated) | Jul 28 – Aug 11 (estimated) |
| Anaheim TMR (opens in a new tab) | Feb 20 – Mar 6 (estimated) | Jul 15 – 29 (estimated) |
 | Feb 20 – Mar 6 (estimated) | Jul 18 – Aug 1 (estimated) |
 | Feb 20 – Mar 6 (estimated) | Aug 4 – 18 (estimated) |
 | Feb 20 – Mar 6 (estimated) | Jul 25 – Aug 8 (estimated) |
 | Feb 20 – Mar 6 (estimated) | Jun 30 – Jul 14 (estimated) |
 | Feb 20 – Mar 6 (estimated) Seedlings Mar 6 – Apr 3 | Jul 15 – 29 |
 | Feb 20 – Mar 6 (estimated) Seedlings Mar 6 – 27 | Aug 9 – 23 |
 | Feb 20 – Mar 6 (estimated) Seedlings Mar 6 – Apr 3 | Aug 4 – 18 (estimated) |
 | Feb 20 – Mar 6 (estimated) | Aug 4 – 18 (estimated) |
 | Feb 20 – Mar 6 (estimated) | Aug 8 – 22 (estimated) |
 | Feb 27 – Mar 13 (estimated) Seedlings Mar 6 – 27 | Jul 15 – 29 |
 | Feb 27 – Mar 13 (estimated) Seedlings Mar 6 – 27 | Jul 13 – 27 |
 | Feb 27 – Mar 13 (estimated) Seedlings Mar 6 – Apr 3 | Aug 1 – 15 |
 | Feb 27 – Mar 13 Seedlings Mar 6 – 27 | Jul 15 – 29 |
 | Feb 27 – Mar 13 | Jul 30 – Aug 13 |
 | Feb 27 – Mar 13 Seedlings Mar 6 – Apr 3 | Jul 10 – 24 |
 | Feb 27 – Mar 13 (estimated) Seedlings Mar 6 – Apr 3 | Jul 18 – Aug 1 |
 | Feb 27 – Mar 13 (estimated) Seedlings Mar 6 – 23 | Aug 9 – 23 |
 | Feb 27 – Mar 13 (estimated) Seedlings Mar 6 – 23 | Jul 15 – 29 |
 | Feb 27 – Mar 13 (estimated) Seedlings Mar 6 – Apr 3 | Jul 20 – Aug 3 |
 | Feb 27 – Mar 13 (estimated) Seedlings Mar 6 – 23 | Jul 15 – 29 |
 | Feb 27 – Mar 13 (estimated) Seedlings Mar 6 – 23 | Jul 20 – Aug 3 |
 | Feb 27 – Mar 13 (estimated) Seedlings Mar 6 – 23 | Aug 1 – 15 |
 | Feb 27 – Mar 13 (estimated) Seedlings Mar 6 – Apr 2 | Aug 9 – 23 (estimated) |
 | Feb 27 – Mar 13 (estimated) Seedlings Mar 6 – 23 | Jul 22 – Aug 5 (estimated) |
 | Feb 27 – Mar 13 (estimated) Seedlings Mar 6 – 27 | Jul 8 – 22 (estimated) |
 | Feb 27 – Mar 13 (estimated) Seedlings Mar 6 – 27 | Jul 20 – Aug 3 (estimated) |
 | Feb 27 – Mar 13 (estimated) Seedlings Mar 6 – Apr 3 | Jul 5 – 19 |
 | Feb 27 – Mar 13 (estimated) Seedlings Mar 6 – 23 | Jul 17 – 31 |
 | Feb 27 – Mar 13 (estimated) Seedlings Mar 6 – 27 | Jul 25 – Aug 8 |
 | Feb 27 – Mar 13 (estimated) | Jul 25 – Aug 8 (estimated) |
 | Feb 27 – Mar 13 (estimated) Seedlings Mar 13 – Apr 3 | Jul 20 – Aug 3 |
 | Feb 27 – Mar 13 (estimated) Seedlings Mar 6 – 23 | Jul 1 – 15 |
 | Feb 27 – Mar 13 (estimated) Seedlings Mar 6 – 27 | Jul 25 – Aug 8 |
 | Feb 27 – Mar 13 (estimated) Seedlings Mar 6 – Apr 3 | Jul 30 – Aug 13 (estimated) |
 | Feb 27 – Mar 13 (estimated) | Jul 8 – 22 (estimated) |
 | Feb 27 – Mar 13 (estimated) Seedlings Mar 6 – 23 | Jul 15 – 29 |
 | Feb 27 – Mar 13 (estimated) Seedlings Mar 6 – 27 | Jul 13 – 27 |
 | Feb 27 – Mar 13 (estimated) Seedlings Mar 6 – 23 | Jul 19 – Aug 2 (estimated) |
 | Feb 27 – Mar 13 (estimated) Seedlings Mar 6 – 23 | Jul 25 – Aug 8 |
 | Feb 27 – Mar 13 (estimated) Seedlings Mar 6 – 23 | Jul 15 – 29 |
 | Feb 27 – Mar 13 (estimated) Seedlings Mar 6 – 23 | Jul 25 – Aug 8 (estimated) |
 | Feb 27 – Mar 13 (estimated) Seedlings Mar 6 – 23 | Jul 18 – Aug 1 (estimated) |
 | Feb 27 – Mar 13 (estimated) Seedlings Mar 6 – Apr 3 | Jul 12 – 26 |
 | Feb 27 – Mar 13 (estimated) Seedlings Mar 6 – 23 | Jul 25 – Aug 8 (estimated) |
 | Feb 27 – Mar 13 (estimated) Seedlings Mar 6 – 23 | Jul 20 – Aug 3 |
 | Feb 27 – Mar 13 (estimated) Seedlings Mar 6 – 23 | Jul 20 – Aug 3 (estimated) |
 | Feb 27 – Mar 13 Seedlings Mar 6 – Apr 7 | Jul 5 – 19 |
 | Feb 27 – Mar 13 (estimated) Seedlings Mar 6 – Apr 3 | Jul 12 – 26 (estimated) |
 | Feb 27 – Mar 13 (estimated) Seedlings Mar 6 – 23 | Jul 10 – 24 (estimated) |
 | Feb 27 – Mar 13 (estimated) Seedlings Mar 6 – Apr 3 | Jul 30 – Aug 13 (estimated) |
 | Feb 27 – Mar 13 (estimated) Seedlings Mar 6 – Apr 3 | Jul 10 – 24 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 24 | Aug 29 – Sep 12 |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – 30 | Sep 3 – 17 |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – 30 | Aug 19 – Sep 2 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 17 | Aug 4 – 18 (estimated) |
 | Mar 6 – 20 (estimated) | Jul 7 – 21 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 10 | Jul 12 – 26 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – Apr 10 | Aug 14 – 28 (estimated) |
 | Mar 6 – 20 (estimated) Seedlings Mar 13 – 30 | Jul 30 – Aug 13 |
| Scotch Bonnet (opens in a new tab) | Mar 6 – 20 Seedlings Mar 13 – 30 | Aug 4 – 18 (estimated) |
How the dates are calculated
Sowing dates count back from your last frost date by the number of weeks each record lists for starting indoors. Where a record also lists days to germination, the seedling line shows when to expect the first leaves.
Transplanting runs from the last frost date for two weeks: the frost date on its own is an average, and night temperatures usually need that long to settle. This window is a gardening convention applied to every variety, not a figure from the records.
First harvest adds each variety's days to maturity to the window that figure is counted from: the transplanting window for records counted from transplant, the sowing window for records counted from direct seeding. The table says which applies whenever the catalog holds both.
Finding your last frost date
The default date, May 1, matches USDA zones 6 to 7, the region the catalog's calendars are written for. Warmer zones see their last frost earlier and colder zones later. The frost-date lookup above finds the NOAA weather station nearest your ZIP code and fills the date in for you.
Treat the result as a planning window rather than a promise. A cold spring pushes everything later, and a variety listed at 8 weeks before frost will still be fine started at 7.