They had loud fast moving commercials during your favorite television shows that told you to "turn up your doing dial". You ran down to the giant orange store and bought all the plants you could fit into your car. You got those suckers right into your dirt and stood with pride at the end, sweat and soil across your brow, just like the guy on tv.
Then, May in NE carried out the usual punishment for your miseducation. And, the big orange store will get another handful of your hard earned cash. Just like they planned.
Sorry, man, I told ya! You looked at me like I was a fool for waiting and now your plants are dead. Will ya listen to me now?
Don't buy anything from the box stores. You're bringing disease to your garden and to your neighbors, too. That blight last summer? Didn't start at your LOCAL greenhouse. Those plants you bought spent time in a shipping container with thousands of other plants. No one was checking them to remove a diseased plant right away before it infected other plants. At a small, local greenhouse you can be assured that someone is walking up and down those aisles checking plants on a daily basis.
Get the farmer's almanac or similar calendar. The calendar doesn't lie! Here in MA, we can't plant tenders until the end of May. Period. It does not matter if we have hot weather in May, we will always have a frost before the end of the month. If you put tomatoes out before the last week of May, you better have a really good cover system (and even the best are not foolproof).
Turn off your tv. Seriously, turn it off and get out.