Q.Should lavender be trimmed?
I have two kinds of lavender and I am unsure if either needs to be pruned or trimmed.

Certified GKH Gardening Expert
Pruning can help with the health of the plant for sure! This article will help: https://www.gardeningknowhow.com/edible/herbs/lavender/pruning-lavender.htm

In zone 5, lavender is pruned in spring before new growth starts. Trim it to the shape you prefer and remove dead and damaged branches (lavender is technically a subshrub). If there are branches that start on one side of the bush but crazily lean over to the other side, remove them. They block sunlight. If there are large stems with no leaves at the base of the plant, I prune these out, one or two each year, as needed. Once bare, they will not push out new leaves from the barren wood even if cut back.