How hard is it to grow lavendar? Will it grow in Long Island, NY, or is the climate here too cold?
You can grow lavender in in NY, no problem; either you buy a hardy, frost-resistant variety that you can plant directly in the ground, or you plant any variety in pots that you take inside during winter.
I live in France, but in a mountainous region, where the winters are harsh. I've experimented with both, and the frost-resistant lavender is still alive, but not exactly thriving.
However, my pots are flourishing: I take them outside mid-May, and take them back inside at the end of October. You can plant any lavender variety you want in pots, as long as you don't expose them to frost.
Smells wonderful when I step outside in the morning