Having seen tens of thousands of saguaros in habitat, and being a long time owner of several large and small plants, the first one is textbook saguaro. The second cactus looks very different. Skinnier, yes, but sometimes that's a product of how they are grown outside of their region. When I look at ...

Stetsonia coryne.

That looks like corking to me--a normal occurrence on old growth at the base and arms of cacti.

Looks like Pachycereus pringlei to me, or maybe one of the less common Pachys.

Could be spider mites. I get a similar rusty look across numerous Coryphantha species. If it is the same thing, it won't kill the plant, but it will never look the same again.

I would cut off the top where the normal growth ends. It will probably send out offshoot branch(es) from around the top. You can plant the etiolated top in some soil and it will grow normally if you give it plenty of sunlight. Do not grow this plant indoors. You have two years of growth there and it...

teo wrote: ↑Tue Mar 10, 2020 8:10 am A 'normal' rigidissimus or a reichenbachii maybe ?

I think this is exactly right. It's very hard to ID these immature forms with pectinate spines. In addition, reichenbachii has a lot of different varieties.

I've had little to no success getting greggii cuttings to root. Keep us posted on the progress!

very cool!

I grow several of these species, and have quite a few greggii. That's just what they do, with no rhyme or reason to it. If conditions aren't right, stems will dry up and the cactus will put its energy into either the tuber or into new stem growth. It happens to my plants all the time. And at some po...

Nice save and I have to say nicely potted.

I agree with the Mamm tetrancistra ID for that portion of Mojave Desert.

If the pebbles are just for the top dressing, there shouldn't be any issue. They all look healthy from the overview picture. If you are concerned about an individual plant, show a closer view of the area of concern. Also, the amount of direct sun they are receiving won't make the rocks too hot.

Some cacti turn purplish in response to the cold, but given the season, I suspect it has turned color due to the introduction of more direct sun than previously. This is not necessarily a bad thing.

This is what I would do: 1. Cut off the spindly growth at the top of the crest (red line). 2. Cut at the blue line and see if you can root the small stems. Throw out the bit between the red and blue lines. 3. Cut off and discard the stock plant (Hylocereus). It is dead. You may be able to root the c...