I grew up in Fresno, CA & oleanders were commonly planted in highway median strips. They are highly toxic so be very careful if you have kids and/or pets. I also can't imagine it surviving in Zone 6. I'm Zone 7 & can't grow them. I associate oleanders with a dry & hot climate. My Zone 7 coastal climate is too wet plus I don't believe they can handle much more than occassional light frost.

If you have kids and/or pets this might not even be a good house plant.

/tricia

Here is a link that might be useful: Wiki on Oleanders

Oh man... lol. Thanks for the Wiki link. After reading how toxic it is, I'm not sure I want anything to do with it. Although it's suddenly become fascinating and horrifying, I might just let it flower from some high place in my yard, then say bye-bye to it in September. I've got cats and a baby step-grandchild who's at the age where everything goes into his mouth. Thanks for the heads up, tricia!

Pam

When planted in the ground, they can be successfully grown in Z7. I have one that has braided stems, to form a tree and a friend has one that is several years old, in the middle of his front yard, unprotected.
The standard species form can become quite large. I have seen them in downtown Savannah, GA that are at least 15x15ft. There is a dwarf form, which is planted in the median of I-95 through GA, that only grows to about 5x5ft.
in size.
I doubt that animals would be interested in this plant, as it is one of the most poisonous plants in the world. But humans don't have the sensitivity to avoid toxins.
Placed near the South facing foundation of a heated building and covered with frost cloth, burlap or a "shrub coat" and protected from cold winds, you might be successful in growing them as a garden plant.
For insurance, take cuttings before first frost and root them indoors, for planting next year.
Rb

rb is correct, and I would say that they don't mind heat or humidity, at least the ones that are grown in the south. They are very commonly grown all along the gulf coast and it doesn't get much muggier than here.

Oleander, to my mind, is a lax, rangy, floppy plant. The foliage has little to recommend it either (in my opinion). It's only real redeeming quality is the lovely blooms, and the long bloom season. Maybe I just haven't seen them grown well. The braided stems idea is interesting. Either way, grow it in a safe place this year and see if it's worth the trouble of protecting it. You'll surely get your dollar's worth. :)