Here they start do die when the temp get below -10C, so I have to protect them..
My Neriums have flowered from july and they're still flowering after a night with -0.9C . They flower the hole summer, but they're as you know very toxic.

Oleanders will not live outside in my zone 5b - I bring them indoors at the end of October, where they promptly lose all their leaves, but that's ok, because they start re-leafing in March.

For in ground, unprotected plants I would say it has to be at least a solid zone 8A...they are huge and everywhere in zone 8b. The leaves apparently get defoliated by the cold at 18-19 degrees and the plant begins to die @15 degrees. I have seen many that have taken repeated hard frosts in the low 20's with no damage whatsoever.

I would agree with Wilmington Islander's rough estimates of hardiness. They are often seen thriving in California's central valley, which in the far northern reaches as you approach Oregon can get considerable cold in winter. They are most definitely a risk to plant if you regularly drop below 20F in winter, but may come back from the roots from 15F if they are mature plants. Here in California, they tend to show freeze damage at 25F or lower, although this may be a function of not having fully hardened off in fall as we often stay warm until the first killing frost in more inland locations. I wouldn't advise this as a good safe landscape plant below USDA zone 8b.

They are very easy to grow as container plants, and if you can greenhouse them in winter and give them the full sun and heat they prefer in summer, they ought to do well as container plants. I would suggest that some of the dwarf cultivars, a pink and deep red are the two most common here in California, might be better choices to save space in the greenhouse. Maybe you should be thankful that they will never get 20 feet tall as they can here. You will also find that they are very subject to Oleander aphids(usually bright orange in color), which also attack Asclepiads/Butterfly Plants.

My oleanders of common variety, sold in Home Depot-like stores, were badly damaged at -4oC during several nights(leaves mostly, even in sheltered spot). Had to pot them and bring them inside a week ago.

Some oleander cultivars are more cold tolerant than others. In the southeast US climate, "hardy pink", "hardy red", and "double yellow" appear to be the most cold tolerant. I'm growing "hardy pink" and "double yellow" here, where they have taken 11F with almost no leaf damage. Compared with the typical less cold hardy cultivars, the cold hardy cultivars tend to be shorter and more broader in their growth habit. The flowers of "double yellow" are fragrant.

Plant Delights Nursery in North Carolina carries many "tropical" plants that are relatively hardy. They've collected oleanders, palms and the like that have survived the most severe winters in the zones 7 & 8 of the South. Check them out. Not cheap, but they do have what you are looking for.

No matter how hardy the variety you can get, they are brutal with snow loads. The crushing weight of the snow severely deforms their stature. A common problem with evergreens.

Cheers, Barrie.

I purchased a bright deep red oleander a few years ago at Wal-Mart. It is beautiful but I don't want to take a chance of it dying even in my area. It does well outside until Christmas in south Virginia. But then I bring it into an unheated porch until April.

the double yellow variety is called Mathile Ferrier ..it only blloms one time in the early spring time ..

another hardy one if you can find it ,is an orange variety called " FDR "

check out the international oleander society site in Galveston Texas

http://www.oleander.org/

and enough of the poisonous thing about them ,,, there are many plants that are also poisonous ... don't eat them

I grew 'Double yellow in New York which survived 4 degree temps with some damage. I found an oleander from Wal-Mart in a New york yard that was planted on the north side of a house. it was untouched after a mild winter with a low of about 11 or 12 degrees! The variety was not listed on the tag. I may try oleanders again in my 7b climate in lower Cape May County, New Jersey.
Good luck!
Palmfan
p.s Yes! I grow palms here!

You may find some Nerium oleander that is suitably hardy for your garden, HOWEVER, these a plants are terrible with snow loads. They will lay over and stay that way long after the snow is gone. An overhead canopy would solve that problem.

Cheers, Barrie.

Zone 6 in SW Michigan, have wintered over yellow oleander from Plant Delights. No protection, dies back to ground, regrows weakly early summer, has never bloomed. I'm beginning to wonder ... what's the point?

the double yellow oleander ,. Mathile Ferrier,,is the hardiest ,,however it only blooms once early in the season and the buds are formed the previous summer ,,should it ever bloom for you ,,it is the most fragrant of all ,,, oleanders are related to plumerias

I have successfully overwintered mine with regular lows of 25-30 degrees and not much higher in the day. Under these cold/dry conditions (I don't water them over winter, well, maybe once on a mild day) they hold all foliage and get right back into geer once they go out (mid March, depending on the weather). I take them in some time in early December (before hard freezes). The only problem I have is that mine is too big and cannot be put into larger pot! For those in a similar position, yes you can take cutting. I take cutting in July or August and put them in moist sand (they'll root).

My Oleander has come back this year, but of course we had a very warm winter this year. We will have to see what happens as far as blooming and all.

My one oleander, an impulse buy on a trip to Sacramento, didn't survive record snows (although not record low temperatures that year) in 2004. There are enough other plants for me to fool with that I haven't gotten around to killing oleander a second or a third time.

Old thread but I tried a home depot pink (exact variety ownknown) here in z7. It held up fine to an exceptionally heavy snowload but started browning in February. By spring it was completely dead.

I've tried one in my garden here in relatively mild coastal Delaware (zone 8a), but it didn't make it this winter. However, 3 miles away in Rehoboth Beach there is a specimen out front of a B&B that has been there a few years. It gets more sun than my spot and is up close against the porch. I'll give it a try again this year with a similar, more protected spot in front of my porch.

I have an unamed double pink in a pot which has been thorugh 3 winters outside with temps down to -5C on rare occasions. However, my problem is that the summer isn't hot enough for it to open its flowers fully.

I bought a red one and planted it in the ground. I protected it with some x-mas lights and a frost cloth with a plastic trash bin and it survived with no damage. Now I think its starting to get ready to bloom again for the year, or at least make some new growth! They are pretty hardy plants, Mine went down to around 20F.

Here in northern italy, in the alps oleanders seem to grow fine. I've seen oleanders growing in a town near here where the sun doesn't come out from November to January because of the mountains. Temperatures very often fall below -15C there. I have Oleanders in containers that have overwintered fine every year with temps below -10C. Maybe the plants here are more used to the cold.

I live mid Vancouver Island Canada, I have 6 Oleanders 3 red and 3 white bought at Rona. The red ones began to look lose all the leaves mid november so I brought them inside and over the winter they became covered with crabby looking bugs..it seemed as tho the bark opened up and the bugs came out..then the rest of the leaves died.I put them out in MArch and the leaves came back and they flowered..so not sure what that infestation was. I want to plant them so will take the persons advice to put Christmas lights around them. Wondering if the Italian Alpine variety have a genus and perhaps I can find some of those.The scent is intoxicating and I think that is worth the babying:)

well I just planted my oleander on the east, out side, I'm going to rap them with new paper and plastic, mulch and a big box on top. wish me luck see you next spring

Wow...talk about an old thread.
No oleander is truly hardier than about 7b at the very best, in the most sheltered spots; really it's more like 8a. And that's only for the hardiest cultivars. Even as far south as Virginia Beach they get killed to the ground about every 10-20 years. I think this winter would have severely damaged any non-hardy cultivars there, but they are seldom cultivated in borderline areas. The tender ones are so much nicer - larger, more fragrant flowers, longer blooming, etc. If you just want to grow one in a container, skip 'Hardy Pink' et al.

BTW The areas in the Italian Alps with oleanders do not go below -15C regularly, they are in fact zn 8 or even zn 9 or 10 near or on the lakes. (Isola di Brissago has a mature norfolk island pine!)

And btw it was funny around Lago Maggiore, in typical residential gardens I saw the rather boring hardier oleanders. Probably because the Italian nursery industry produces them in large quantities for the whole north of the country, like Milan and the Po Valley, which are generally zn 8. However all of the famous area gardens had HUGE examples of the tender, double, fragrant more tropical seeming oleanders...proving the overall mildness of the climate. (the gardeners of Isola Madre told me the typical winter low is -3C)

I have a "double yellow" in the front of my house, in Budapest, Hungary in zone 7B.

yeah that's the hardiest one in the US SE too, it has a proper cultivar name...'Mathilde Ferrier' probably

Interesting update. My relatives in Virginia Beach told me the city removed a lot of oleanders after the 2 recent cold winters. However, they just cut their plants back to the ground, removing the injured sections, and they are already full, 4-5' high and blooming their heads off. So stupid! They already told me that in the past that the same thing happened after 1985 and 1994. The city removes them after they are injured, then decides to replant them a few years later when there is a string of "mild winters". Likewise my relatives just cut theirs back and let them regenerate! Oh well, I guess all of this unnecessary make-work keeps people employed.

Based on Csaba's post and what I already knew about their ability to regenerate quickly, I could not resist trying a 'Mathilde Ferrier'. I have had nice strings of 8a winters...hope they come back. (last winter was not that cold, but was damaging because it was capricious) It will go on my hottest south-facing stone wall of course. Also they are relatively easy to propagate so I will keep a backup plant inside.

Oleanders are virtually care free. They're probably one of the top 5 most common plants used throughout California. You'll find them in parking lots, homes, businesses, lining city streets, and along freeways for miles and miles. Freeway 99 is lined with multi-colored oleanders almost continuously from north of Sacramento to Bakersfield (a distance of roughly 450 miles). I'm unsure of how much cold they can take as I have never thought of oleanders as tender plants - I just know that we've had freezes over the years with temperatures going down to the mid 20s and the oleanders have never shown any sign of stress. They can take all the abuse you can throw at them - even coming back after being hacked down to the stumps or after a fire. A business near me has oleanders in large planters in their parking lot, in full sun. They receive very little water at all, even in 110 degree heat

Josue,

Many of the oleanders on 99 were removed for lane additions.

David, I live in Rockport Texas on the coast,as far as yellow oleanders go,I have not seen any around here or even up to Corpus,all the yellow we see here are called Esperanzas, they tolerate cold but lose all leafs in winter,Last year we had one day of 27 degrees, my oleanders suffered leaf burn,But we mainly grow,Hardy Pink, Red, Golden Coral color, and the HUGE white ones,.. My suggestion is this as I do, Plant your oleanders on the south end of your home near your home,That way they get the most sun all summer through winter,it is Dec.1 here 2017 after hurricane harvey they stood firm, and mine flower all year round,but more flowers in heat of summer.By planting them on south end blocks north wind, My white ones do not flower all year,thats why I stick to the pink, dark pink red and coral colored they bloom all year round even in temps down to 40's down here. Oleabders are tough,even if they are cut after establsihed into the ground cut low,cover them in winter and in summer they will come back with a vengeance of growth.

I tried oleander once in my old zone 8 Seattle garden. Was planted in a very sheltered, heat reflective location. Lasted about 4 years, dying back pretty fully each winter, before giving up completely in one rather harsh winter. Never did flower either, so I'd have to ask what the point is...........sometimes zone pushing is just not worth the effort.

OP David was last seen in 2010: https://www.houzz.com/user/david-5311

But, hey who knows, maybe he will come back by.

Oleander might find the PNW a bit too chilly to properly harden wood. They were mostly OK in the VA Beach after the polar vortex winters. Although not nearly as cold down there as up in DC (or even the middle of the Delmarva Peninsula) it still would have been a very cold winter by PNW standards. I think lows were in the upper single digits in the mildest areas. Away from the coast, it was 2F. In fact, right on the water, there were fully trunked Butias and huge Agave americanas that survived both winters, albeit with some damage.

I still haven't planted my 'double yellow', I know it will die in colder winters, I really need to have a backup ready. Propagation time! Big established ones do recover at lightning speed down there, as I noted above.

"Oleander might find the PNW a bit too chilly to properly harden wood"

That seems to be the case with a number of otherwise zone appropriate (or close to it) plants. For example, it is very rare to have a loropetalum survive here over winter and it's always a toss up with pittosporums, although I have had great success with a few selected culitvars.

btw david, I was driving by my old house yesterday (moved away going on 10 years now) and overlooking the almost total disarray of the previous garden - current owners are NOT gardeners!! - I was surprised to see my old Azara microphylla approaching the 20' mark....and about double the width it was when I left. I might have to find space for one in my new garden - that fragrance in February when it blooms is heavenly!!

So far Azara is the most heat and humidity resistant Chilean plant I've tried. Of course, it is going to die down some winters here, no doubt. Fingers crossed that it can recover quickly...Escallonia 'Apple Blossom' (or whatever it really is since Embo insist that name is wrong) did somehow linger through the epic hot summers of 2010-2012, the polar winters 2013-2015, and the strange and capricious weather since then. But it's hardly a garden performer. It hasn't bloomed most years and looks under the weather. (no pun intended!) If the Azara has just a little more vigor - and it appears to - it might prove to be satisfactory.

I'm trying the typical species (A. microphylla of course) and also a supposedly hardier clone. I haven't experienced the flowers but I'm also enamored with the zig-zagging branching pattern.

We had a bad storm in Texas mid-January. The temps outside at my house got down to 5 degrees Fahrenheit two nights in a row, and daytime temperatures were in the mid to low teens. I am in zone 8B. The leaves are all brown. Do you think the plant is dead or do you think an oleander can survive 5 degree F temps?