Seed starting countdown
Tick the crops you are growing. The countdown works back from your last frost date to tell you when to sow each one, when to start hardening off and when to plant out, and how many days are left.
Next up
Sow broccoli indoors
Thu, Feb 11, 2027
-
Sow indoors
Sow broccoli indoors
Feb 11
Allow 4–6 weeks from sowing to planting out, so any day from Feb 4 – Feb 18 works.
-
Sow indoors
Sow lettuce indoors
Feb 11
Allow 4–5 weeks from sowing to planting out, so any day from Feb 11 – Feb 18 works.
-
Seedlings up
Broccoli: seedlings should be up
Feb 14 – Feb 21
Most seed comes up 3–10 days after sowing.
-
Seedlings up
Lettuce: seedlings should be up
Feb 15 – Feb 21
Most seed comes up 4–10 days after sowing.
-
Sow indoors
Sow peppers indoors
Feb 25
Allow 8–10 weeks from sowing to planting out, so any day from Feb 18 – Mar 4 works.
-
Sow indoors
Sow tomatoes indoors
Mar 4
Allow 6–8 weeks from sowing to planting out, so any day from Feb 25 – Mar 11 works.
-
Harden off
Start hardening off broccoli
Mar 4
Set the seedlings outside for a few hours in shade, out of the wind, and leave them out a little longer each day for two weeks.
-
Harden off
Start hardening off lettuce
Mar 4
Set the seedlings outside for a few hours in shade, out of the wind, and leave them out a little longer each day for two weeks.
-
Seedlings up
Peppers: seedlings should be up
Mar 7 – Mar 17
Most seed comes up 10–20 days after sowing.
-
Seedlings up
Tomatoes: seedlings should be up
Mar 10 – Mar 18
Most seed comes up 6–14 days after sowing.
-
Plant out
Plant broccoli out
Mar 18
Hardy enough to plant out before your last frost. Wait until the soil is at least 40 °F at 4 in (10 cm) deep in the morning.
-
Plant out
Plant lettuce out
Mar 18
Hardy enough to plant out before your last frost. Wait until the soil is at least 35 °F at 4 in (10 cm) deep in the morning.
-
Harden off
Start hardening off tomatoes
Apr 8
Set the seedlings outside for a few hours in shade, out of the wind, and leave them out a little longer each day for two weeks.
-
Harvest
Lettuce: first harvest
Apr 12 – Apr 22
About 25–35 days from planting out; varieties differ, so check the seed packet.
-
Harden off
Start hardening off peppers
Apr 15
Set the seedlings outside for a few hours in shade, out of the wind, and leave them out a little longer each day for two weeks.
-
Plant out
Plant tomatoes out
Apr 22
Frost-tender, so plant out only after your last frost. Wait until the soil is at least 50 °F at 4 in (10 cm) deep in the morning.
-
Plant out
Plant peppers out
Apr 29
Frost-tender, so plant out only after your last frost. Wait until the soil is at least 60 °F at 4 in (10 cm) deep in the morning.
-
Harvest
Broccoli: first harvest
May 17 – Jun 6
About 60–80 days from planting out; varieties differ, so check the seed packet.
-
Harvest
Peppers: first harvest
Jun 18 – Jul 13
About 50–75 days from planting out; varieties differ, so check the seed packet.
-
Harvest
Tomatoes: first harvest
Jul 1
About 70 days from planting out; varieties differ, so check the seed packet.
How the dates are worked out
For crops started indoors, the planting-out date comes first: University of New Hampshire Extension gives a safe week relative to the last frost and the weeks each crop needs from sowing to planting out, so the sowing date sits in the middle of that range. Hardening off starts two weeks before planting out, following University of Minnesota Extension: put seedlings outside in shade for a few hours, then a little longer and sunnier each day. Days to germination and the soil temperature to wait for come from Colorado State University Extension. Crops sown in place get a sowing window instead.
Using the calendar file
Add to calendar downloads an .ics file with one all-day event per step. Open it with Apple Calendar, Google Calendar or Outlook to import the reminders. Your frost dates and ticked crops are remembered in this browser and shared with the planting calendar.
Sources
- University of New Hampshire Extension. Growing Vegetables: When to Plant Your Vegetable Garden [fact sheet]. extension.unh.edu
- University of Minnesota Extension. Starting seeds indoors. extension.umn.edu
- Whiting D, O’Meara C, Wilson C. Vegetable Planting Guide. Colorado State University Extension, GardenNotes #720, 2018, reviewed 2024. extension.colostate.edu
- Grandpre A. Can I Grow That Here? Vegetable Seed and Transplant Schedules for Garden or Container. Montana State University Extension MontGuide MT199308AG, revised 2018. extension-store.montana.edu
- Jadrnicek S, Hessler A. Virginia’s Home Garden Vegetable Planting Guide: Recommended Planting Dates and Amounts to Plant. Virginia Cooperative Extension 426-331, 2025 (Table 5). pubs.ext.vt.edu
Questions
Why not sow as early as possible?
Seedlings kept indoors too long get tall, weak and root-bound. Sowing within the suggested range gives sturdy plants that are ready just as the weather is.
What if my seedlings are ready but it is still cold?
Wait. Frost-tender crops such as tomatoes and peppers can be harmed by frost, and an average last frost date still has about a 50% chance of a later frost. Pot the seedlings on into bigger containers if they need more room.
Does it work for crops I sow outside?
Yes. Tick carrots, beans or any crop without the indoors tag and you get its outdoor sowing window, when seedlings should appear and the first likely harvest.