Use Soilless Seed-Starting Mix
Use the right mix for starting your seeds. Commercially formulated seed starting mixes are soilless, meaning they are specially blended to be relatively sterile and free of weed seeds. Most contain milled sphagnum peat moss with vermiculite and/or perlite, plus a bit of dolomitic lime, a wetting agent, and sometimes fertilizer.
There is nothing so frustrating as looking at two different but unnamed tomato seedlings, or wondering is this a yellow or orange marigold? Label your seedlings from day one. I use masking tape and an ordinary pencil to label each container with the name and date seeded or transplanted. Wooden or plastic labels work fine too.
Mark Seed-Starting Dates on Calendar
Many popular annual and vegetable transplants only require six to eight weeks head start indoors, some need ten or twelve. To know when to start your seeds, check your average last spring frost date. Then count backwards the recommended number of weeks and mark your calendar for when to start the seeds.
If you overwintered geraniums, salvias, begonias, and other tender plants, now is the time to take tip cuttings for rooting new starts. This allows you to prune back the parent plant and thus encourage denser new growth, as well as increase your supply of plants for the coming the season.
Check Frost Heaving
Recent freeze-thaw cycles may have heaved shallow-rooted plants right up out of the ground. (Routine mulching over the root area in late fall helps prevent this.) If you find a plant popped up on the surface, toss mulch over the roots until the next thaw when you can replant it.