Here’s when you need to plant your vegetable seeds
The list below is the basic seed sowing dates for a USDA zone 4.
Add a week for every zone colder and subtract a week for every zone warmer — “roughly” from the dates given)
One thing I would note is that these dates are not carved in stone. You can (and should) modify them to suit your own garden and situation. If you have a warm garden -advance things a week or so- but if you live in a frost pocket, then you should consider adding a bit of patience to your gardening repertoire.
These are best estimates and guidelines. Where there are both indoor and outdoor, you have a choice. Where there is only one, you generally use that system (if only indoor, you start seeds indoors).
But to answer a question that’s sure to be raised, can you start seeds such as corn indoors to get an early jump on the season? The answer is that you can start “any” seed indoors if you want to do the work. And take enough care with the transplanting.
But I confess I sow everything I can outdoors and only start plants such as tomatoes and peppers indoors.