Cold snap and elms in Arizona

[AaronThomas]

Hey all! Quick question... We have had a pretty warm January here in AZ... Upper 60s and lower 70s during the day and in the 40s at night. My elms started budding so I was able to root prune and re-pot a few weeks ago. This week there are green leaves on my trees.
This next week we are expecting day time temps in the low 40s and nighttime temps to dip in to the 30s and even in the upper teens. (so much for a quick question)
I was wondering if I should put the trees in the garage for a few weeks or will they be okay if I place them by a glass door next to the house under a covered patio. I also would also cover with a drop cloth to keep frost off. Just not sure how the cold temps will effect the freshly potted trees and new growth!
Thanks!!!

 

[Dav4]

You shouldn't let them see freezing weather again this winter, but if they have leaves, they will need sunlight during the day, sooooo....it's time for the bonsai two step!!!

...which means inside the garage at night and outside in the sun during the day if it's above freezing.

 

[AaronThomas]

Awesome... lol.... Looks like l'm going to get a bicep workout!
Thanks for the reply!

 

[rockm]

Ditto Dav4's response. A note that once deciduous trees' buds have opened (even a little, even if you can juuust see leaf edges on the bud) they lose almost ALL of their winter hardiness, and have committed their resources to growing. That means, a freeze that gets to the roots WILL most likely kill your tree. Frost exposure will blacken leaves into the spring. Spring is a very dangerous time for temperate deciduous bonsai.

The "bonsai two-step" is a regular dance bonsaiists in colder areas do every spring. You have to keep an eye on the weather like a farmer. We get frosts here into mid-April far past the time leaves on some trees have emerged and well into repotting season. I bring ALL those trees INSIDE the basement when the forecast predicts nighttime temps of 39 or so. I move them back out when forecasts go back above that. This can happen four or five times in a month.

Don't take the weatherperson's word for the low. Assume it will drop three to five degrees below what they say, especially in less populated, building free areas.

This is most likely more important to you since you live in a desert and nighttime temps can drop fast and hard because your arid environment typically little or no humidity that can keep conditions warmer. Radiational heating is also a concern, exposed areas will get frost even if air temps don't go below 40.

 

[AaronThomas]

HAHAHAHAH..... Annnnnd. Its snowing.

Thanks Rockm
This will be the first tango er... two step ill be doing with the bonsai. Glad its not a long trip!