What did you want it for???

If you are growing for stalks to make moth scarers for your wardrobe, or for making lavender-flavoured sugar for baking (for example) - then the English lavender (angustifolia) gives the 'true' lavender scent as well as the tiny flowers along the spike - so handy for adding to pot pourri. It also clips quite well into neat domes and low hedges. Should be ok in zone six with a touch of kindness.

If you have a hot and dry place (south wall under the house eaves) then the French lavender (L dentata) will smile serenely, tolerate the abuse, flower for months and sigh but survive when you hack it back to shape. A bit more frost sensitive but is fine so long as the wood is ripened over summer. Has a more resinous scent than 'True' lavender IMO - and the 'bunny ears' petals on the top of the flower stem.

If you have anything remotely looking like a frost I'd avoid Sidonie. She's a sensitive piece and goes flabby, filamentous black with the slightest chill.

L x intermedia are the ones to grow for a general lavender scent, flower variations, oil production. The oil (spike lavender) is not as good for healing IME but it is fine for aroma. They also clip well.

I'm not so fond of green and white florals in lavender but the pinks can be useful rather than just 'curious'.

They will come from seed but cuttings will probably give you replacement plants more quickly - and they're not hard. Good drainage and fresh air seem to be important in the process.

Lavenders are Mediterranean plants, so a climate most similar or duplicating those growing conditions as much as possible will give you the best results.

English lavenders (Lavandula angustifolia) are without argument the most cold hardy - easily to zone 5. The lavandins (Lavandula x intermedia) are close on their tail, but these vary quite a bit with cultivar. These are the taller stemmed, heavy oil producers that are used in the perfume trade. I'd avoid Spanish (L. stoechas) or French (L. dentata) - neither of these will be reliably hardy in 6; most won't even overwinter consistantly in my very mild zone 8 and we have the US's largest commercial lavender growing operations nearby.

I'd go with one of the English cultivars - 'Munstead' or 'Hidcote' are deep colored, compact and robust plants. Lavenders (of all types) need full sun and well drained, rather lean soil. Avoid overly fertile soil and make sure drainage is very sharp - that is the key to successful lavender growing. Water only enough to get them established and do not fertilize. Trim back lightly in late summer after the flowers fade but give them a closer cut in spring when you see new growth appearing. Don't cut back into bare wood. An annual spring shearing will ensure the plants stay dense and compact, maximize the flowering and keep the plants from splaying or developing overly woody interiors.

It is certainly not too late to plant now. Most nurseries should be offering lavender starts with their herbs. There is also a specialty lavender nursery in Harwich, MA - Cape Cod Lavender Farm. I've never grown lavender from seed but it can be reliably propagated from cuttings. If you have concerns or want to try a marginal variety, lavender does very well in containers, which can then be moved to winter protection. It will not be happy indoors, however.

Wow, Thank you so much for the full response :) I'm printing it to follow as I go along. Now that you mention it, I do remember seeing a kit of some sort at the nursery with the herbs.
Again, thanks for your help!

Hi Jenn729. I have had luck with growing Hidcote, Lady and Munstead here in Central Maine. No special winter protection is offered to any of them, nor are any placed in any special microclimates. I have bought several plants from nurseries, but I have grown most of them from seed (I bought the seed from Thompson and Morgan, and had good success, even though it was still while I was a seed-starting novice). I have read that winter sowing works well with lavender, but have never attempted it. Good luck- I love my lavender and you will too.