What you have is lavendula dentata,(lavandula stoechis), French lavender. it is only hardy to Zone 8 so would be unlikely to live over winter in the ground in Zone 6, let alone in a pot.

It's Lavandula stoechas, which is distinct from L dentata. (Note that the leaves are untoothed ie not dentate). As callirohoe123 says it is one of the more tender lavenders and rarely survives the Winter even here in the UK. It will be happier and easier to grow in the ground than in a pot but it would be most practical to treat it as a seasonal plant. They are very hard to get through the Winter indoors unless you have a greenhouse or lighting setup. Even then they are tricky.

Thanks to everyone for your input. I'm really disappointed. I'm not sure why Costco would sell and label it as a perennial here in zone 6. I have not planted yet and will consider returning. In the meantime I will remain hopeful for my lavender plant from Trader Joes. There's also a lavender farm in Morganville, NJ I want to check out. I'm sure I can find the Munstead variety there.

Thanks again for your help!

Botanically speaking the label is correct - it is a perennial. I imagine they sell the plants everywhere with the same label so buyers need to research for themselves. Not very helpful but not surprising for a big company.

Hi Paulina,

It's a bit late to jump in but I wonder what became of your lavender.

I too am in New Jersey and bought the same lavendar at Costco. It has been in the ground since last summer and has survived the winter really well. It's still green and upright and has only a couple of dry spots. I planted in a spot that gets about four hours of direct sunlight.

Hope this helps!

Hello Madreselva!

I returned the plant. Im happy to hear yours is doing well. Our winter has been pretty mild with the exception of todays snowfall. I returned the plant because I feared it wouldn't survive NJ's traditional winters.

I am excited to say that I have been lucky with lavender plants from Trader Joes! I have one in the ground that I bought last May and another in the house that I picked up recently and it's doing really well with small blooms. Ive posted pictures on another thread about that plant.

Please keep me posted about the progress of your Costco lavender.

I plan to vist Well Sweep Herb Farm in Port Murray, NJ in the next few months to see what kind of lavender plants I can find. They always have a nice selection of healthy organic plants!

Thanks for your input!