Here is a couple of links. The first discusses growing heathers in cold climates:

http://www.heathsandheathers.com/care/page3.html

and the second specifically deals with growing in Canada:

http://www.heathsandheathers.com/care/page5.html

How much snow do you get? If you reliably get good, deep snow, you can plant some of the lower-growing varieties of heather and after the ground freezes, mulch them with cut pine branches to help create some protection. Then, once it snows, they will be protected from the worst extremes of the weather. No guarantees, but it might be worth trying. I did that with some varieties that aren't totally hardy where I am, and it worked pretty well.

I've been wondering the same thing about growing them in zone 6. We often have very cold spells but when that happens, there is usually no snow cover.

Do you completely cover them with the cut pine boughs or just cover the ground under them?

I have read that winter wind is bad for them and we have a lot of that. I've been trying to figure out where on my property to plant some. I'd like them close to the house so I could see them better but the winter wind worries me.

I cover the plant, though not densely, with the evergreen boughs. Your Christmas tree, after you take it down, will provide nice stiff needled branches to drape over the heaths and heathers. It shelters them a bit from both winter sun and wind, and if there's any snow at all, it tends to get blown into the heather plant and evergreen branches and stay there to help shelter the heath/heather.

The heathsandheathers.com site (see cranebillÂs post) does give good information. Here in the East, we get much of our information from rockspray.com. Rock Spray is a zone 6 nursery on Cape Cod, but they can be very helpful about which heathers are most hardy. Since you are more centrally located (east-westwise), I don't know which would give you better shipping rates, but both are worthy of investigation.

The other posters here talk about protecting Calluna and Erica by covering them, after the ground freezes, with evergreen boughs. In your climate especially (Zone 3 is iffy for heathers), the importance of this cannot be overstated. And for strong springÂfall growth, be sure to site them properly: sun, water (until well established) with excellent drainage and with the soil conditions (acidic!) they want.

Don't overlook the winter-blooming heaths (Erica), as many of them are very hardy with attractive foliage year-round. (They look great with grasses, too.)

Here is a link that might be useful: Rock Spray

I planted 5 erica darleyensis in April when they were in full, saturated bloom. They looked great then and even after they stopped blooming, I had good looking plants with no foliage turning brown at all. I thought they were supposed to be in bloom again now, but all I have is about 40% of the density I had at planting. Is it too soon to expect them to look as they did when I planted them? Also, I was told they are tolerant of alkaline soils and I do indeed have clay soil and I haven't fertilized them since I planted them using root starter. Anyone have any experience with these plants they would care to share?

Eight years ago I planted heathers. They all did fine (I'm zone3/4) as long as I had snow. Last winter they all died - no snow and deep freeze (-20 F) did them in. They were beautiful while they lasted and were pretty big (almost 2' in diameter). I have always covered them with either leaves or pine needles and then evergreen branches. The winter protection unfortunately didn't help when we didn't get the snow.

Thanks for answering my questions! I forgot that I had posted here:-( I bought 2 E. dar. and planted them in Nov. They immediately turned brown. This always happens when I plant Erica.