A white or clear plastic bottle or jug with the bottom cut from it can be used to buffer and improve the outdoor environment for little tiny seedlings. Put the jug over the wee plant. I use this for garden plants in the early Spring.

Use mulch also. Fine pine bark, peat moss, grass clippings/straw, wood shavings/sawdust, works to buffer the topsoil's moisture and can help with insect pests too.