How often do you feed the plant? Since it's already established we can rule some stuff. But 2 reasons that come to mind are either lack of nitrogen from fertilizer and insects. You may want to check your plant for that as well.

My dragon fruit turn yellow what is happening?

Pictures? Location? You need to provide a bit more information.

It was probably due to the cold weather. Over 200 of my dragon fruit turned yellow. I am waiting to see if it recovers. It shriveled up too.

The first thing that happen to my dragon fruit was chlorosis. It lost it's green color and started turning white and shriveling up. After it warm up for two weeks, it started turning yellow.

As long as the branch doesn't start rotting, I will not cut it. There wasn't much damage and I got to see if it can recover from the cold weather and how long it takes.

My dragon fruit also turns yellow due to the lack of iron in the soil. I just add some iron fertilizer. One plant turn completely yellow. It hasn't turn yellow since. After a big harvest from the one plant, I just add a little more iron fertilizer. It first started turning yellow about two months after I picked all the fruits off it.

Hello I need your help about dragons fruit I have 5 buckets with different dragons fruit ONE of them turn yellow/green the next is GREEN ??? why one of those yellow/green I check soil if wet its not wet trying to figure because all 4 other buckets healthy let me show you picture please tell me what's wrong ?? Thank you for your help and have a great day :) Brett

I would start watering it first. Not all dragon fruit cutting successfully root. Some actually die.

Planting two segments or more is harder for the plant to root. An example would be if you were to cut the whole tree and plant it in the ground with no root, then the entire tree would die.

As you see other picture came out great the tall one grow faster and keep watering ?? well sometime I feel inside soil its moist its why not wanted to overwatering I guess I might pull out bad one other leave it ??

Tony I put bareroot put in soil than water in cup not good moist soil can help most almost all cactus never use water cup to grow root only soil I had been thru most cactus I had :)

I planted the dragon fruit cutting a feet deep in the soil and most of them died. Then I planted it no more than 4 inches deep like the planting guidelines suggest and all of them survived.

Oh yes not feet that's too deep yes 4 inches about right anyway i throw away bad one cuz I have other same as bad one no worry anyway many thanks Tony :)