A: Good for you for returning to composting. Yes, the same rules still apply: no meat, bones or grease; no eggs, but eggshells are OK; no salad greens if they have dressing on them; no animal feces and no cat box litter — really just common sense to prevent attracting rodents and other animals and spreading disease.
Your excess seeds can go in the compost pile if it’s well-managed and “cooks” to a temperature of at least 140 degrees — check with a soil thermometer. These are the minimum temperatures that will kill the seed’s ability to germinate. A bonus: Next spring as you turn the pile, you may see some tiny tomato or pepper or pumpkin seedlings that have survived — either save them or turn them over.
The soil in plant containers doesn’t have to be completely replaced every year — every two to three years is often enough — but you will want to do some soil amending every year. Do it in the spring or fall: Remember that you don’t change all of your garden soil every year, but you do add supplements and soil additives like compost and fertilizers after a soil test.
In your containers and raised beds, scrape off the top few inches of soil and replace it with good composted soil, either bagged or homemade, every year. If you use bagged potting soil that has a fertilizer already added, do your soil replacing in the spring because the fertilizer will only last about six months once it gets even slightly damp and containers will be in storage those months.
Any soil you remove from containers can be added to the compost, a 1- to 2-inch layer at a time. It will add beneficial microbes as it combines with other materials. Extra soil can simply be used in the yard to fill in or level areas or wherever you need extra soil — or can be used as mulch in the garden and spread around — then it will combine with chopped leaves that you’re going to compost this fall and winter.