2012 Seed Starting & Planting Schedule

Sue from Ohio recently requested that I post a time line for my seed starting dates. What a great idea! Knowing when to plant each vegetable is often difficult to determine, but it’s key to success. And it just happens to be one of the things I talked about last spring when I put on my Master Gardener hat at our Spring Demo Day event. So I dusted off the notes from my talk and tweaked them a bit for the following.

me speaking at 2011 Spring Demo Day

me speaking at 2011 Spring Demo Day

Let me say right up front that all the date ranges I am going to throw out here are for gardeners with climates similar to our own USDA zone 6B, and with a similar length growing season. For example, here in southern Indiana there is less than a 10% chance of having a frost after the last week of April. If you wait until May 1st, there is pretty much a zero chance of frost. In fall our first frost usually occurs around the last week of October. So that gives us around 180 frost free growing days each year.

seed packets (click on any image to enlarge)

Many state universities have free gardening resources available online, and I urge people to use them – it’s your tax dollars at work! Purdue University has a publication called Indiana Vegetable Planting Calender (HO-186W) that I use to develop my own planting schedule.  Ohio has some good ones too, and you can find links to many of them on this web page.

In the table that follows ‘sow’ refers to direct seeding outdoors, and is usually done for peas, carrot, corn, radish, spinach, beans, and turnip. ‘Start’ means starting seeds indoors in pots, soil blocks, flats, trays or cell packs, and is usually done for broccoli, cabbage, cauliflower, tomato, pepper and eggplant. Things like beet, Swiss chard, lettuce, arugula, endive, kohlrabi, kale, squash, melons, pumpkin, cucumber and many of the Asian greens can either be direct seeded outdoors -or- started inside. I often start these vegetables inside under lights to get a jump on the growing season. ‘Plant’ means to plant transplants outside or to directly plant things like onion sets, sweet potato slips or seed potato pieces.


  • Start broccoli, cabbage, cauliflower, Florence fennel, kale, kohlrabi, lettuce, parsley


  • Sow arugula, mache, spinach


  • Sow peas, radish, spinach, arugula, endive
  • Plant onion(sets or transplants)
  • Start lettuce, pak choi, early tomatoes


  • Start eggplant, tomato, pepper


  • Sow beet, carrot, chard, lettuce, radish, turnip
  • Plant broccoli, cabbage, cauliflower, chard, Florence fennel, kale, kohlrabi, lettuce, onion, potato


  • Start lettuce
  • Sow beet, carrot, chard, lettuce
  • Plant broccoli, chard, Florence fennel, kohlrabi, lettuce, onion, potato


  • Sow green bean
  • Start cucumber, melon, pumpkins, squash
  • Plant lettuce


  • Sow corn, cucumbers, green bean, melons, pumpkin, squash
  • Plant cucumber, lettuce, melon, pumpkin, squash, tomato


  • Plant pepper, eggplant, okra


  • Plant sweet potato


  • Start fall broccoli, cabbage, cauliflower, collard greens, kale


  • Sow beans (snap), beets, carrot, chard, peas, turnip, kohlrabi
  • Plant fall broccoli, cabbage, cauliflower, collard greens, kale, kohlrabi


  • Sow arugula, Asian greens, endive, lettuce, mache, radish, spinach
  • Plant Asian greens, endive, lettuce


  • plant garlic


I have to emphasize that the above dates for sowing and planting are guidelines only! Last year was a great example. We had record rains, and a cool wet spring, which made it difficult to get the soil prepared. It also made the ground slower to warm up. Another way to decide when to plant certain vegetables is to use soil temperature.

soil and instant read thermometers

You can find soil thermometers at many garden centers, but you can use any type thermometer as long as it registers in the necessary range. Take the soil temperature by inserting the thermometer in the soil where you intend to plant the specific crop. An instant read thermometer is also good to monitor the temperature of your seed starting mix. Following is a table listing the minimum soil temperatures preferred by certain vegetables. Seed packets and catalogs are a good source of information regarding germination temperatures (Johnny’s Selected Seeds is one of my favorite sources).

  • 45°F – potato, onion, peas, spinach, arugula, lettuce
  • 50°F – broccoli, cabbage, cauliflower
  • 60°F – tomato, corn, beet
  • 65°F – cantaloupe, cucumber, green bean, pepper, pumpkin, squash
  • 70°F – lima bean, okra

For instance, if you plant your tomatoes when the soil is below 60°F, they’re just going to sit there and sulk. If you plant seeds when the soil is too cold, they are likely to rot. Some seeds (like lettuce and spinach) won’t germinate when the soil is too hot. Of course there are ways to warm up soil faster in spring, like using black plastic or raised beds, but that’s a subject for another article! I also plan on doing a few more posts in the near future regarding some of the specifics about my seed starting techniques, including soil mixes, lights, heating mats, and so on. So stay tuned if you are interested!

Ultimately, I use a combination of the calendar, soil thermometer and the weather report when making the decision of when to plant. My above lists don’t include all vegetables by any means, but do include most of the ones I grow regularly. I hope this information will be helpful. If anyone has any questions, I’m always happy to try and answer them.

I can see it is time for me be starting some seeds of the cabbage family here ASAP, along with some petunias and parsley. So I better break out the seeds and soil mix and get growing!

For more about growing plants from seed, see my page on Seed Starting Information.

For more information about specific fruits and vegetables, see Variety Spotlights.

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10 Responses to 2012 Seed Starting & Planting Schedule

  1. Aimee says:

    A great guideline – thanks for posting this. We’re in zone 7b, so not terribly far off from your schedule at all.

  2. Daphne says:

    I use a latte thermometer to tell how warm the soil is. I don’t do it often though. Only if I’m worried I might be pressing too hard on the seasons.

    We are both zone 6b, but your season is so much longer. Our last frost is usually sometime in late April. I consider May to be a reasonable last frost date here. Our ground is frozen solid usually until mid March so we can’t plant in February. That being said, I’m hoping to sow a few things this year very early. So maybe for the first time ever I’ll sow in February.

    • Dave says:

      I took our soil temp today and it was 40°F – pretty warm for February! I’m not sure of ours froze for more than a day or too, and not solid at that.

  3. mandy says:

    oh, thank you for posting this! i just planted a bit of mache and claytonia yesterday.

  4. Robin says:

    I am in 6b also. But, it we definitely have a shorter growing season then you by a couple of weeks. It seems like you are more like Zone 7. I have adjusted my schedule a bit this year due to the garden move.

    • Dave says:

      Our weather has been more line zone 7 the last few years. Of course you can’t really count on that for perennial plantings, but I have been pushing the season in both directions with vegetables.

  5. meemsnyc says:

    Looks like you are growing a nice variety of edibles this year! What a great list!

  6. Rick says:

    Great post, thanks for the info. I’ll be posting a similar list on my blog next week for our Zone 5 b garden. 180 frost free days!! Wow, last year our last frost was after the first of June and our first frost was September 29th! I’m really jealous!

  7. Sue says:

    what a great post! I am in Zone 6A or 6B. I will use this as my garden bible. Thanks a million.

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