Cycas multipinnata cold tolerance

[tank]

Looking for info on the cold tolerance of C. multipinnata.  I saw in an old post that Tom Broome had mentioned that all of his pinnate cycads (including C. multipinnata, I believe) had seen down to 21F with minimal or no damage.  Presumably these were planted in a frost free spot under canopy.

I can confirm that both of my  C. deboaensis and C. micholitzii saw 24F (frost free) and did not show any damage.

Thanks for the help!

[Merlyn]

I had similar experience with frost-protected 24-26F on Micholitzii, Bifida, Debaoensis, Multifrondis and Multipinnata.  The one Multipinnata out in the open didn't take any immediate frost damage, but about 3-4 weeks later all the leaflets died.  It's flushing now, a bit over 4 months after the freeze.  Here's the temp profile for that weekend, the Cycas are all in the backyard 2 zones:

The one Multipinnata in the nursery zone took no damage and is currently flushing too.  It's a whopping 10' tall now and hasn't even started unrolling yet.  You can see the older frond dangling down in the center, just to the left of the Bottle palm's frond. 

[tank]

@MerlynThanks for the info!  That's a pretty detailed weather report for your yard.