Obtusifolia Cold Hardiness

[MarsOfOld]

I have a 15" Obtusifolia plant with a woody stem I've raised indoors in a large pot that is now thriving outdoors this summer. What are the odds of it surviving outdoors where the winters go down to -20C with snows up to three feet deep (Northeast USA)? If I formed a cone of mulch around it, do you think it would survive to awaken in the spring? Should I bring it indoors to keep it alive? I'd prefer to plant it in my yard...

[Auxin]

Chances of survival are quite seriously low I would think.

You could pot it in a large pot or the ground, let it go wild all summer, then cut back its branches and roots to fit into a 3 gallon pot to live indoors over the winter and repeat in mid-spring. After a few years of that you might have a interesting 3 foot bonsai each winter.

[Mycot]

A.obtusifolia seems quite cold hardy in Australia in the sense that it does grow in regions that recieve snow.

As for the low temps you speak of Mars we dont receive too much of that in Aus.

As for whether A.obtusifolia could tolerate those conditions I think it would be quite experimental. I dont think anybody really knows how cold-hardy A.obtusifolia is. (more input appreciated)

Mulch is always a good idea for minimising fluctuations in soil temp.

[gerbil]

Yep what's said above...also it's important to realise that 'A. obtusifolia' cold hardiness is relative to where the genetics have evolved. There are some specimens in some regions that can't take the cold extremes that others can.

There were photos a few years back with obtusifolia pot specimens (seedling/juvenile from memory) in the blue mountains which had a few inches of snow on them and they were looking fantastic, but i don't know about 3 foot at -20C.

[foolsbreath]

I had one in a pot outside during winter

It lived through a -16 a -13 and a couple -9's with the rest of winter being between -7 and -3, some of the frosts were so hard you could see the frost 3m up trees, no snow here during winter, its not really the climate, but we get the odd one in spring and autumn. Our day temps would get up to 10degrees + during those days however. This was last winter, this winter the nights have not been as cold, but the days have been cooler.

I suspect snow can have a insulating effect in some cases, and being in the ground would dramatically increase survival chances over potted.

[MORG]

De ja vu?

http://www.shaman-australis.com/forum/inde...;hl=obtusifolia

[MarsOfOld]

I guess I'll just have to treat my Obtusifolia as an indoor house plant. Oh well, there's always Leptolobus. Since it seeds up the first year, then it doesn't need to survive the winter. Just have to tolerate the lower percentage of alkaloid...

[Auxin]

I still think planting it out for late-spring and summer could get it to make lots of growth and eventually make a very interesting jumbo bonsai.

Is leptolobus 0.02-0.04% like illinoensis?

[Pisgah]

Auxin, I've found that too many repottings really hurt the overall health of my plants. Field planting during growth season a'la bonsai caliper growth technique wouldn't pay off. At least that has been my experience, and to be honest I'm sometimes neglectful of some of my plants.

Obtusifolia dies below 5deg F (sorry, don't have Celcius in front of me) IME. Died in a container, and died in aerated clay in the yard. Bear in mind, this was with year old plants at best.

Mars, the most cold hardy plants I have ever grown were from the seeds you gave me (and I've sourced them from ALL over). And they are still germinating 2 years later. So hopefully that is encouraging...

I will actually be planting some obtusifolia in the ground, in the back of a covered, unheated greenhouse where I work. I'm hoping the protected, but cold environment will provide a good growth space for obtusifolia.

[Mycot]

Obtusifolia dies below 5deg F (sorry, don't have Celcius in front of me) IME. Died in a container, and died in aerated clay in the yard. Bear in mind, this was with year old plants at best.

It should be noted that A.obtusifolia strongly dislikes clay soils and this may have contributed to problems.