Ohio Vegetable and Flower Seed Starting and Planting Calendar

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 30^th, 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

Summer and Autumn Seed Starting and Planting Schedule for Zone 6