Do you have good luck with lavender?  If not, there are a few possible reasons why the plants don't succeed.

Lavender needs the same amount of sun as roses--at least six hours of direct sunlight per day.  If your lavender doesn't get enough light, move it to a better location.

Lavender must have excellent drainage.   If heavy clay soil is a problem, transplant your lavender to a raised or sloped bed.  You can also amend your soil with grit.  Without soil amendment, the plants will be prone to rot.

Some lavenders are more cold-tolerant than others.  Before you buy, check the USDA zone hardiness number on the seed pack or nursery tag.  Despite the effects of climate change, you will have better luck with lavender if you match the plant's zone hardiness requirements to the zone in which you live.

Lavender looks beautiful and smells great.  It is well worth a little extra care and attention.