In my area, and in many areas in Southern Canada and the Northern US, snow has come early this year and the ground is all covered in white. In most places, all this snow will probably melt away over the next few days only to reappear in a more durable form later in the season, but even if it does persist, that doesn’t mean it’s too late to finish the last plantings in your garden. If you have bulbs that you put off putting in the ground or shrubs or perennials still sitting around in pots, just plant them.
Planting through snow couldn’t be simpler: just brush away the snow from the planting site with a broom or shovel and dig a planting hole. You’ll probably find the surface of the soil is frozen, but so what? Just break up the frozen crust with your shovel. The soil underneath will still be perfectly friable.
Plant just as you would have done if the snow wasn’t there, digging a hole to the desired depth (as deep as the root ball is high for potted plants, 3 times the height of the bulb in the case of fall bulbs). Add compost, mycorrhizae and/or fertilizer if you feel they are needed. Now, center the plant or bulbs in the hole and fill in with soil, tamp down lightly, then water.
The only difference to your usual planting technique comes afterward. It would be wise, as you finish planting, to cover the area around the plant a good 6 inches (15 cm) of mulch (consider a mulch of dead leaves, since they are probably abundant at this time of year). The mulch will slow frost penetration and give the new plantings a little more time to root in.
Planting through the snow? There’s nothing to it!