The whole gardening year lies ahead of us and it’s really getting cranking! The soil is warm enough for many types of seeds and transplants.
A note on transplanting seedlings vs. planting seeds:
The case for transplanting vegetable seedlings as opposed to planting seeds directly in the garden was made best in the book The Market Gardener: seeds take up valuable garden space while they grow. If you plant already-growing plants, you’ll maximize your garden production space. If you have indoor growing space, you can start these seeds in cell trays indoors. If you don’t, buy seedlings from a nursery. (Professional growers really know what they are doing, so you’re going to get the best results from professionally grown seedlings.)
Some things are just better planted as seeds—root crops like carrots, parsnips, and radish don’t love transplanting.
You can plant both seeds and seedlings at the same time, by sprinkling seeds around the transplants. A great example of this is lettuce; a week or so after you plant lettuce seedlings, sprinkle 10 lettuce, arugula, or radish seeds around them. The lettuce will get harvested and new ones will be growing in its place.
What you can plant now, in mid to late April
Our last frost date is coming up; optimistic sources suggest it’s late April. Conservative sources say it’s May 15th. It will likely be somewhere between those two. There’s really no need to rush it and plant tender seeds like beans and cucumbers. Even if our last frost is genuinely in late April, the soil will likely be too cold for warm-season vegetables and the seeds will rot.
So enjoy the season. No need to rush it.
Indoors in cell trays
The only things you’re going to be planting indoors in pots now are warm season transplants, such as:
Seeds you can plant directly in the ground
If you bought them, or grew them yourself and they have their first true leaves.