What’s the best time to plant determinate tomato seeds for transplanting into containers?

Question:

Need a recommendation for the best time to plant determinate tomato seeds for transplanting into containers. We are located in Phippsburg, Maine.

Answer:

In our climate, we need to start all types of tomatoes indoors and then transplant them outside after the risk of frost has passed. So, you’ll need an estimate of when your typical last frost in the spring will be. This map from the Northeast Regional Climate Center may help. Tomato seedlings are usually started 6-8 weeks before that last expected frost date. Supplemental lighting and a heat mat can help get the seedlings up and going. More information about starting seeds can be found in this UMaine Extension fact sheet Starting Seeds at Home.