Prune after they flower with a light trim. If you do it now you'll lose any flowers. The whole of the plant is scented so it's up to you which bits you dry and keep.but the unopened flower buds are the usual thing.

I am not sure why they said to wait - there is no demand of the plant that would call for that.

We have a great many commercial lavender farms in the area and their practice is the one I advise as well. Start pruning your lavender at the end of its first summer. Unpruned lavenders do have a tendency to grow leggy or extend rapidly and if not addressed while still very young, these will develop a very bare woody interior and begin to splay or flop open. Not a nice look :-(

So prune at the end of the flowering season (late summer/early fall) beginning that first year, removing the old flower spikes and just an inch or so of foliage. In spring as new growth emerges, you can prune back a bit tighter but never back into bare wood. As the plant matures, this early spring pruning becomes even more important as it keeps the plant compact and dense and encourages additional flowering tips. And prevents the flopping or splaying.

So trim back lightly at the end of the season and a bit harder at the beginning of the season as new growth becomes evident.

Thanks to both of you. I will go ahead and do a light pruning since I didn't last year but be sure not to cut into any woody stems.

I need yall's advice as well. I have a young lavender that I planted in the beginning of this summer. I'm not sure what type of lavender it is. It's healthy and growing well, but it's leggy now. Every post I've seen about pruning young lavender states to prune after flowering or it could prevent flowering next year, but here's the thing... mine has never flowered, not even a bud. So what do i do? Prune, or leave it alone?

I also have the same issue with my young rosemary as well.

How and where are they planted? Both need very well drained soil in as much sun as possible but the soil needs to be lean - not amended or enriched with any compost of fertilizers. That can make the plant leggy by encouraging unnecessary growth. And reducing its ability to flower well.

FWIW, you can prune back lavender whenever you want. It blooms on growth produced the current season so pruning now has NO effect on next year's flowering. And rosemary blooms in late winter or early spring.....it is past its common bloom cycle.

HU numbers. My statement above about pruning after flowering was written in April and referred to losing the current years flowers, not next years. After flowering they need tidying up anyway. Otherwise you're left with a mass of dried up flower stalks sticking up out of the bush.