it is planted outside, east facing in front of house in the anza borrego desert there is another planted across from it doing just fine nice and green.
Unfortunately, your photo did not come through. I am unable to see the damage.
There are several things that can cause yellowing. My first suspect is overwatering. This can cause root rotting, which can cause the symptoms that you are seeing.
Next will be a lack of sun. They need as much as possible, and planted on the East side of a structure can cause enough shade for it to be unhappy.
This article will help you to know what care these plants require:
I read in your article that it puts on a fruit. I never knew this. I've always removed the wilted blooms so the plant could focus it's energy. I would like to experience the fruit, if I can.
Is your cactus outside? To get fruit, your cactus must be pollinated during the night by a moth.
Should I trim off these red leaves...like 3 feet of my plant?
Darkening or black leaves on a cereus are not good, and can indicate the plant is dying, although not always. It also can mean too much sunlight. You should remove these darkened leaves and, just to be safe, take some cuttings from the healthy parts of the plant and root them in case the plant doesn't survive. Here's an article for that: https://www.gardeningknowhow.com/ornamental/cacti-succulents/night-blooming-cereus/night-blooming-cereus-cuttings.htm
My NBC’s leaves look yellow and has some holes, what’s wrong? Fungal and over watering? The former owner told me it can’t be grown indoors (but reading posts here seems like it can? I live in SF) the plant just produced a bud so I assume it’s doing ok? But would love to keep the new leaves green! TIA.
I think that you have hit the nail on the head. Ovewatering and fungal issues seem to be the perfect fit for what I am seeing here.
They don't perform their best indoors. That is for certain. When grown indoors without supplemental lighting, they will stretch and grow long and lanky, as you see there. That isn't to say that it won't grow, but it won't look its best.
These are cacti, but they will tolerate a little more water than a typical cactus will. It still needs a thorough dry out between waterings. I would suggest, at least, halfway down the container between waterings.
Here are some articles that will help:
https://www.gardeningknowhow.com/garden-how-to/info/using-fungicides-in-garden.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/testing-moisture-in-plants.htm
I did find this plant on the street and try to take it in a year ago. The new leaves would shrivel into black and the old leaves would do that eventually as well. There were bugs in it I realize I didn’t properly get rid of the old soil. So this summer I fully repotted it, cut off all the blacken leaves and a bunch of new leaves grew and I thought it got better for 2 months. Now new growth are starting to shrivel again and I notice there are tiny black spots on the leaves. I rarely water it now following the app Planta’s recommendations
In order to rid the plant of the infection, it will need to be treated. A fungicide will be in order. This article will help:
https://www.gardeningknowhow.com/garden-how-to/info/using-fungicides-in-garden.htm
esp in storm can you trim it If so how?
This cactus will reach a mature height of about 10 feet. At this point, it will be a little under halfway to its full, mature height.
However, this tangled mess of a plant will tolerate pruning, as long as the temperatures are not at extremes (The coldest and hottest parts of the year). In fact, you will find that it grows out of control when left unkempt.
Here is an article that will help you to care for the cactus properly:
There are 3 buds on single leave but 2 buds are turning yellow while one is growing with green
Unfortunately, your photo did not come through. I am unable to assess the issue at hand.
I would check the soil nutrients and pH. It could be that the pH is off, or that there are potassium and phosphorus deficiencies.
Here are some articles that will help you to test the soil:
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/testing-soil.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/soil-ph-plants.htm