Garden Gaslighting: don't be fooled by April!
A vegetable garden is an exercise in patience - waiting for things to grow, waiting for the right time. It's also an exercise in avoiding temptation and amateur weather forecasting, especially in the D.C. area where spring can feel like summer one day and winter the next. This extreme temperature variability makes it very difficult to know when to start seedlings, and when to transfer them into the eagerly awaiting garden beds. Get tempted too early and you're holding a memorial service for your dearly departed seedings. Wait too long and you miss the best growing weather.
Forecasts of the last freeze are best guesses based on past data, and it always seems like no two years are the same here. And it is easy to be lured in by an early heat wave, which can make you think that the coldest days are behind you.
That is exactly what happened this year.
Here is what our April has looked like thus far.

We (mostly my other half) took the bait.
When the forecast looked like it was only going up, we thought we could plant some tomatoes. Just a couple, thankfully. It was easy to think that the worst weather was behind us. Turned out we were wrong, and after a stretch of warm days that had us breaking out the summer wardrobe and evening turning on the AC, we were plunged back down into winter temps. Heat was turned back on, coats were worn, and a couple of tomato plants died.

Amazingly, one strong little seedling appears to have survived thanks to our attempts to keep it warm with a tarp, and I think will pull through.

More thankfully, we made a bunch of backup seedlings for exactly this scenario. For those seedlings, we will follow standard local advice and keep them under the growing lamp until after Mother's Day weekend.
Hopefully in the future we can learn to be a little more patient with our planting.