I am in Alabama and looking to direct sow seeds into my vegetable garden. One problem - we are expecting 5-6.5 inches of rain over the next two weeks. While there are dry days in there that I could potentially sow, I am concerned about too much moisture rotting my seeds. How much rain is too much rain for newly sown seeds? If I wait until after this rainy spell, I am concerned that it might be getting too late in the season for certain vegetables. I could start the seeds indoors and transplant later but I would rather avoid transplanting if I can.
I would also be worried about the seeds being washed away. Your plants won't survive in standing water. If your beds are well draining, such as in raised beds, they may be OK, but there is still the issue of washing away. I think I would wait to plant or go ahead and start indoors.
https://www.gardeningknowhow.com/plant-problems/environmental/flood-damage-garden.htm
Is it best for me in zone 4a, to plant wildflower seed now or in the spring?
If you have your site prepared and you have had several hard frosts you can plant them now, provided they are hardy to zone 4. Any annuals I would wait till spring.
Here is more information:
https://www.gardeningknowhow.com/garden-how-to/gardening-by-zone/zone-4/zone-4-seed-starting.htm
Most seed packets recommend planting in the fall or the spring after risk of frost. I am in the northeast, is there a difference between planting seeds in the fall and planting in, say, February if the seeds don’t need to be buried and the surface of the ground isn’t frozen or snow covered?
This is dependent on the plant type and exactly which zone. You will want to follow all instructions for zone 5 since that will dictate what and when you can plant. This information will be on the back of the seed packet. In your area, you will still be experiencing times of frost, so you will have to take into account your last frost date for most seeds.
Right now, carrots should be direct seeded, where as something like peppers should be started indoors at this time. Everything you need should be on the back of the packet of each seed, though, so following those instructions will be best.