Outside over wintering of a lavender plant.
I purchased a lavender plant this spring and planted it in my flower garden. It is doing so well. Gets lot of sun and the butterflies love it! I am now concerned how I care for it coming in to winter. Do I Cut it back? Do I cover with burlap ( or something else) to prevent frost / snow killing the plant? I do not know the varietal of the plant.
The biggest risk to lavender during winter is poorly draining soil that stays wet with resultant root rot. Nothing you can do above ground will help; planting in well-draining soil, amending with coarse sand or pelite in heavy clay soil, is most important. Lavender needs pruning annually. Some do this in late fall when it is dormant or early spring as growth begins. Here are articles on lavender care: https://www.gardeningknowhow.com/edible/herbs/lavender/pruning-lavender.htm