Hello, I have a 6 or 7 foot pencil cactus grown from a small cutting I received about eight years ago. My questions are, I want to move the plant from it's current 20" x 20"x 20" container to the ground. Would it slow down growth when I put it in the ground to leave it in it's container, or move to a larger container? The cactus has four main trunks or branches. I would like to remove two, to improve the appearance. Shall I remove one at a time to not shock the plant as much? Also , can I replant the two trunks after cutting them off? What's the best way to do this. Thanks for your advise.
Ok, first thing is be careful. Toxic and irritating sap that can cause blindness! Next, have a read here, though this is primarily about propagating from cuttings: How to Root a Euphorbia Tirucalli (this is your fallback position) Secondly, here are the suggestions on repotting: How to Transplant a Pencil Cactus If you are moving from pot to ground, you will not want to change the soil medium (i.e., plant it into existing soil / re-use what you dug out for the hole) For pruning it, I think you can do that anytime without adverse effects -- just note the cautions about handling the sap of the plant (goggles, etc.)
Definitely pay attention to Daniel's info, nasty sap is nothing to joke about. I can speak from experience with other saps ;-) With regard to your specific questions, it all depends. Most plants prefer in-ground planting, but not all. I find cacti and succulents as a rule prefer to be in smaller pots than you would normally think, so if keeping in a container keep it smaller than your gut tells you ;-) My opinion is that separating then growing in different areas is generally safer and better than keeping a plant in a single container, so I would suggest removing two and planting in another container is a positive step (all other things being equal). As for replanting: yes, definitely -- after you let them air dry for at least a day or two so any wounds have time to dry and callous.
