One of the biggest challenges I face with a large garden is keeping track of when to start my seeds indoors and when to plant the seedlings outside. If I start them too early, then the plants can become huge and root bound weeks before it is time to move the plants outdoors. If I start them too late, then I end up with smaller plants than I had intended for planting outside, or even missing the optimum sowing dates completely.
This seed starting chart is for Plant Hardiness Zone 6B and assumes good weather for the “start outdoors” options. It also assumes planting out from mid-April to mid-May, as the “last frost” in my area is at the 50% chance there are no late frosts in May. (Hah). I adjust as needed for warmer or colder than usual spring weather and am updating it regularly.
For my area:
- The average last frost in Spring is by April 30th, but there is still a small chance of frost between May 1st and May 10th.
- The average first frost in Autumn is between October 20th and November 1st.
- The frost-free growing season is around 170 days.
With this timetable, I start plants that need a longer growing season indoors and under lights, as this gives me a head start.
I move my more cold-tolerant varieties to the garden in mid to late April and plant out the heat lovers like tomatoes and peppers by mid to late May, after the ground has warmed up.
It’s a good idea to keep a journal of your seed starting dates, along with when the plants germinate and how they grow. This will make it easier to find and adjust your schedule to the dates that work best for your area and setup. I’ve moved some of my own start dates a little later because the plants were getting too big too soon for the space and pot sizes I have.
Treat the charts as a general guideline: the time for germination and growth rates can vary widely depending on your individual seed-starting setup and growing conditions. For example, using a heating mat will speed up the number of days to germination, and the temperatures in your seed-starting area can impact the growth rate of seedlings. Good lighting is important for getting your plants off to a healthy start.
This is the evolving schedule I use for starting seeds and transplanting seedlings. It is a work in progress and will be updated regularly to include more vegetable and flower varieties and occasionally to tweak the start and transplant dates.
Winter and Spring Seed Starting Schedule for Zone 6
| Weeks before last frost (April 30th) | Approximate Date | Start Seeds Indoors | Start Seeds Outdoors | Transplant Outdoors |
|---|---|---|---|---|
| 12 | Feb 5th | celery | ||
| 11 | Feb 12th | celery leeks | ||
| 10 | Feb 17th | celery, celeriac leeks | ||
| 9 | Feb 26th | leeks broccoli eggplant ground cherries | ||
| 8 | March 5th | leeks Hot Peppers broccoli Sweet Potato slips eggplant ground cherries | ||
| 7 | March 12th | Peppers Sweet Potato slips eggplant ground cherries | ||
| 6 | March 19th | sweet potato slips onions Peppers Tomatoes Potato seeds cotton collards | ||
| 5 | March 26th | onions Tomatoes lettuce sunflower Potato Seeds cotton collards | chard – Soak overnight first | |
| 4 | April 2nd | onions bunching onions Tomatoes lettuce sunflower Potato Seeds cotton collards | chard – winter sow or in ground | |
| 3 | April 9th | bunching onions | beets chard – winter sow or in ground | |
| 2 | April 16th | okra | beets chard – winter sow or in ground | |
| 1 | April 23rd | okra | beets lettuce chard – winter sow or in ground | lettuce |
| 0 | April 30th | okra | beets lettuce Swiss Chard | lettuce onions Broccoli |
Summer and Autumn Seed Starting and Planting Schedule for Zone 6
| Weeks before first frost (Nov. 1st) | Approximate Date | Start Seeds Indoors | Start Seeds Outdoors | Transplant Outdoors |
|---|---|---|---|---|
| 26 | May 3rd | Brussel Sprouts | onions Broccoli sunflower | |
| 25 | May 10th | Brussel Sprouts | onions Broccoli sunflower | |
| 24 | May17th | Peppers Okra sunflower | ||
| 23 | May 24th | Okra | Peppers Tomatoes Okra eggplant | |
| 22 | May 31st | Okra | Peppers Tomatoes Okra eggplant | |
| 21 | June 7th | Okra | Tomatoes Okra | |
| 20 | June 14th | Okra | ||
| 19 | June 21st | Brussel Sprouts | ||
| 18 | June 28th | Brussel Sprouts | ||
| 17 | July 5th | Brussel Sprouts | ||
| 16 | July 12th | |||
| 15 | July 19th | |||
| 14 | July 26th | |||
| 13 | August 2nd | |||
| 12 | August 9th | beets | ||
| 11 | August 16th | beets | ||
| 10 | August 23rd | beets | ||
| 9 | August 30th | beets | ||
| 8 | Sept 6th | beets | ||
| 7 | Sept 13th | |||
| 6 | Sept 20th | |||
| 5 | Sept 27th | |||
| 4 | Oct 4th | garlic | ||
| 3 | Oct 11th | garlic | ||
| 2 | Oct 18nd | garlic | ||
| 1 | Oct 25th | garlic | ||
| 0 | Nov 1st | garlic |