I recently edited the data for Musa basjoo to read z9a instead of z5 hardy Japanese Hardy Banana (Musa basjoo). I've grown basjoo for 3 years, two winters, so just minor experience. MOBOT indicates z5 then notes various overwintering methods under Culture. Also noted is "basically evergreen" in z9. http://www.missouribotanicalga...
I added a comment about how I mulch mine. Does this seem reasonable?

It's listed in the Southern Living Garden Book as root-hardy to at least zone 6 (and below with adequate mulching). I think the entry data should indicate that and not zone 9 but that's just one opinion. It is the hardiest of the musas and if I was looking and saw zone 9 I would pass right over it, but it grows all over the place here.

I agree with SongofJoy. The hardiness field is describing survival, not evergreen status. Basjoo survives very cold winters and our database should reflect that for the benefit of people looking for hardy banana varieties.

Basjoo gave up the ghost here, even kept inside over winter! After a couple of cold summers with temperatures mostly between 14-16C I guess they didn't have the will to grow and flourish, bananas stop growing at those temperatures.

I still have a lone Musa sikkimensis I grew from seed which is hanging on, it does better here although it's not that great, I bring it inside over winter now I'm down to one. If we have warmth in spring that does help if put in a greenhouse but springs of the last few years have been lousy too, at times 4-6C in April. Spring often doesn't roll on until three weeks into April, then it can be sporadic. Zones don't reflect the growing season or maximum temperatures, they only reflect the expected minimum which puts us in zone 8a although every 20 to 30 years we get an exceptionally cold winter as we had last winter with temps. at or below freezing for 7 weeks and down to -17C at night.

The tall and short of it is you need a good long season and more warmth than we get for any Musa to grow and survive. There's a hardier one which the species escapes me now, the local garden centre had some surviving outside in the ground but last winter killed just about everything they had.

Would be interested to find out the name of the hardier one as everything I've known and read says that basjoo is the hardiest of the Musas? Our temps get down to the single-digits every winter and sometimes to 0º F and occasionally below zero. Basjoo does fine here but we do have a fairly long and sometimes very warm growing season.

I tried to find the one I was thinking of but I'm not sure what it was called, there is one called Helen's hybrid which grows up to 5,500 feet in the Himalayas..

http://www.rarepalmseeds.com/p...

More to check out!

http://www.rarepalmseeds.com/a...

Janet you should copy and paste your above into a comment for this plant, for the benefit of those who visit the plant's entry in the database via a Google search.

Yes, there are a lot of hybrids. Musa basjoo is cold hardy to -20 F so I am considering it the most cold-hardy that people here will grow. Sorry if I didn't make myself clear. The USDA zones are US zones.

Back to the question and topic of the thread. For the purpose of the database we need to make sure that people have a relatively accurate idea of the cold-hardiness of a plant. With M. basjoo, it's far hardier than zone 9. I want the database to be as accurate as possible and I believe people know the various zones contain micro-climates with them that don't fit the exact parameters of the temp range. It may not be perfect but it's the system we have to work with here. I think clarifying is better than than not. But that's just my opinion.

Good idea Dave! People can still try them if they want to, in a very hot year as we had in 2006 they did quite well and we had a mild winter to follow but the summer of 2007 was dreadful. One day in mid July only reached 12C!! That's just under 54F!

Tee, the trouble is USDA zones tend to be used here too, although there is a different system that isn't known so well.

I proposed the update to growing zone hardiness to reflect z5. My reason for starting this topic is principally because basjoos principal popularity is due to its exceptional winter hardiness. While sikkimensis is also a fairly hardy variety, my research indicates frozen soil will usually equate with a dead plant. This is not so with basjoo which will tolerate frozen soil.

It should be noted however that this entry will be the only one I've run across in the DB which notes a hardiness zone which requires winter protection. I've also been growing Acanthus Mollis for 3 winters now and it's doing beautifully. Last winter we had temps. below -14F with snow cover and the 2' of mulch cover I use. I would not imply A. mollis is hardy to z5 however. MOBOT also indicates that mulch should be used in z8 or lower. I don't recall reading anything on basjoo in z8 as growers there seem to focus on the edible bananas, at least here in N.A.

Tee do you mulch your basjoo?

Janet -- At first I didn't realized you were in England. How odd that they use the USDA zones there. I've been in your country and I can't imagine that given all the ocean influence for one thing. But I certainly swooned over all those spectacular gardens!

I mulch my basjoo 5-6 inches, Evan, mostly to try to protect any pups that started to emerge late, but they say mulching is unnecessary here. However, I don't totally trust "their" advice. It is reported to be root-hardy to -20. Low for zone 6b is around 0º F. I do the same thing with my EE (which I don't consider hardy at all)' they definitely need to be mulched (or dug) here. Only thing that's killed one of those thus far is too much rain in the Spring.

Good discussion and, personally, I benefited from all the input. I hope many Comments will be added to the listing.

Tee, it's the water which keeps this country 'mild'. There's the Gulf stream which runs up the west side of the country helping our 'temperate' climate. I live over 53° latitude north which is some way up compared to places on the east coast of the US such as Newfoundland which gets colder weather! The gulf stream is said to be diminishing due to global warming which will plunge us into another ice age!

http://modernsurvivalblog.com/...

We also have a jet stream running high up over the country, if that moves south we get the arctic weather pulled down, if it gets pushed north we get warmer weather pulled up from the south such as Africa. We are also exposed to very cold weather in the winter coming from the eastern continental mainland such as from Russia where inland temperatures can be very low. The milder weather usually comes from the south west off the ocean from the direction of the Caribbean.

It makes for 'interesting' weather! That is, often dull, cold and more dull and cold. We feel really priveleged to get some of that stuff called sun and heat.

A plant's ability to survive extreme cold often depends on length of day, amount of sun and heat and length of season. We have very long summer days but very short winter days, it now gets dark before 4pm and will be dark around 3.30pm by the shortest day.

Mulching will definitely be useful, I found two apples under a few leaves from the Horse Chestnut tree which survived last winter! It's the lack of sun and heat which will make the difference, bananas stop growing below 16C so they can't build up strength to survive.

It's not so odd using the USDA zones here when you consider people connect universally, but I don't think many people consider zones here too much other than it will or will not live here, or might live here if you are desperate enough to give it a try.

St. John's, Newfoundland .. Latitude: 47° 34' North

http://www.timeanddate.com/wor...

Lincon UK .. Latitude: 53.2317° north

http://www.metoffice.gov.uk/we...

Yes, the oceans have a huge influence. That's one reason I chuckled so much. So what's a little zone-pushing now and then.


Here's one of the basjoos. This one is about 8 years old.