Hey there John!
It's a good thought, but it may not be possible in that climate. I have a lot of
experience with both in the Virgin Islands, where they grow like weeds!!! In fact, I don't think I ever want to eat Chaya again! Not true, but when it's a major
staple every day...Moringa has millions of possibilities and positives - you can grind it and sprinkle just for the health benefits alone...I'd say if you got the seeds, give it a go if it's for "personal consumption" just for the hell of it and keep your fingers crossed - anything is possible. However, check this out first:
http://www.treesforlife.org/our-work/our-initiatives/moringa
and you
should be able to find your answers...Moringa is a cool looking tree with amazingly versatile properties and benefits.
Good Luck!