I have a roll of bed of lavender. When is the best time to plant it.

after all frost is gone............

Plant it in the spring after the ground has warmed up. I'm in zone 6, and that's about the middle of April - first of May. Gently sprinkle it down every day for a couple of weeks if it isn't getting any rain on it. I hope it's beautiful for you!

That will depend on you last average frost date

Definitely wait until the last frost has passed

Wait until after fear of frost has passed in your area. Although lavender is a perennial, the seeds need warmth to germinate. Good luck . I never had any luck with lavender seeds. I had to resort to buying plants.

I am very interested what is a role of Lavender is it just like rolled up lawn? We don't have that in New Zealand we just plant plants.

It's a roll or bed of grass with seeds. You plant it, water it until it germinates and flowers