I tried to grow some up a 4x4 and the roots didnt want to grab on to the treated wood. Try it and see maybe yours will if not you could always wrap the post with burlap,thats what I did and the roots really grabbed hold of the burlap. I also put my post in the ground and placed the pot s next to the post.

Reb is absolutely correct. Treated wood is not a good host for DF roots. You must cover with burlap or screen or virtually anything else the root can be happy in. Also, having metal mesh at the top is going to allow cold to more effectively attack your DF segments. The metal conducts cold much better than burlap or wood. Regarding your question about two cultivars....plant away. They'll do fine.

Harry

I have a big roll of leftover screen in my garage I can wrap the 4x4 with. I have the pot in the front of the house so if it gets cold I can wheel it into the garage. I guess I could put it out back where my portable greenhouse will be set up in the event of cold temps but there is no one spot that gets direct sun all day because it is on the North side of the house. Any suggestions for a substitute for the metal mesh that is just as strong?
Thanks a lot
Marin

Marin,
exactly how tall is that post? It does seem tall and the pot a bit small, are you at all concerned it may topple with some strong wind? just a thought

Tim

Hi Tim,
It has a base on the bottom and the pot is a heavy ceramic. If we anticipated a storm I could put it into the garage but a flash tropical thunder storm might an issue. I might consider chopping off a foot of the height before planting it because it will definitely be more top heavy after the plant covers the top platform and it is 6' tall now. Thanks for the input.

I suggest not using treated wood, as the chemicals may be taken up by the plant.

I also believe your plant will become top heavy eventually,
you could use "guy wires" for support but that wouldn't be very attractive.

I hope to be planting a dozen or so using a similar setup to what you see in this video I linked below.

Oddly, the video I have found most informative on commercial Pitaya farming just happens to be in a language I cannot understand (Vietnamese ). I was able to translate a little from the on screen text using google translator though.

anyway, in this system, the support goes into the ground, and 4 cuttings are used one on each side of the cement pole.
the plants can be trained up the pole. only 2 or 3 branching is permitted on the way up each side to the top.

Here is a link that might be useful: Commercial Pitaya Farm