Rot-prone vs. heavy drinkers

[fanaticactus]

I'm aware this may be a tall order, but still after all these years and using a much simplified, very porous soil mix, I am still wondering which genera of cacti love lots of water and which are rot-prone when given too much. Can anyone help with a generalized list of each...knowing there will most likely be exceptions in both categories? I'm fairly certain that cacti with origins in high altitudes with little rain belong in the rot-prone category. In my reading so many sources, I gather that Ancistrocactus/Glandulocactus, Discocactus, Obregonia, Copiapoa, and many Mammillaria are water-sensitive and rot-prone.
On the other hand, I understand that the Echinopsis/Trichocereus/Lobivia/Chamaecereus family appreciate a lot of water, as do the 'jungle' cacti such as Epiphyllum, Zygocactus, Harrisia, Selenecereus, and Rhipsalis.
But where do commonly-grown ones fit in?...Rebutia/Sulcorebutia, Gymnocalycium, Echinocereus, Thelocactus, Eriocyce, Stenocactus, Parodia, and Ferocactus?

I have tried many times unsuccessfully to grow Astrophytums and Turbinicarpus, and others with a 'touchy' reputation, so I'm not interested in those in particular and any other of the more 'exotic' nature.

If I have made some incorrect assumptions in my lists above, please correct me--always with the understanding there will be notable exceptions to the 'rules'. Even some very basic guidance would be appreciated. Thanks very much!

[One Windowsill]

I just happened today to read an article from 1975 in the The Cactus and Succulent Journal of Great Britain that covered some of this for a few different cacti from the US. The water-sensitive ones are from real deserts. The gent from Walla Walla wrote:

The generalization that cacti grow in deserts where rain is an unusual occurrence is a poor one.

You have to register for free with JSTOR but then you get 100 free articles per month.
https://www.jstor.org/stable/42786070

[mmcavall]

It really depends on your climate, so maybe what I observe here will not apply to you but:
Gymnocalycium and Parodia can take lots of water, just about as an Echinopsis.
Ferocactus are not root prone.
Rebutia and Thelocactus are more to the root-prone side, but not as much as Sulcorebutia (?)
I really don't water my Sulcos too much. I treat them like Eryosice, Copiapoas, etc.
Discocactus, despite of the fact that they are native to Brazil, are really sensitive to overwatering.

[keith]

Cactus from real deserts instead of semi deserts are usually more rot prone. Astrophytums, ariocarpus and turbinicapus and some Mammillarias are rot prone. Echinomastus is extremely rot prone. Echinopisis and Notocactus are OK with more water and humidity.

Most anything at Home Depot is not too rot prone because they over water all cactus.

[MikeInOz]

If you work out what states your cacti (or groups of cacti) come from, then cross-reference rainfall patterns, it will give you a good idea of where you stand.
Here for example, is Mexico... Basically everything from the north (and most of Texas) will be water sensitive. You will find Arizona spp. even more so but check rainfall patterns over the year as well because some have very dry summers (parts of Arizona I believe, and coastal Chile, Southern Ca)
After a while you can pretty much guess by looking at the plant but it's always good to check
https://geo-mexico.com/?p=9512

[fanaticactus]

I thank you all who have responded so far. All of this is excellent information. I neglected to mention where I am located. I am on an island--connected to the mainland by bridges and US Rte. 2--in Lake Champlain in northwestern Vermont, eight miles--as the crow flies--from the Canadian border. Being right on the lake, we have our own microclimate; I believe we are in agricultural zone 4b. Our winters are less snowy than in the mountains and inland valleys, but our summers can be hot and humid. We are entering such a period right now. It always seems to be windy, so much so that trees tend to grow with a slight lean to the north because of the south wind coming up the lake valley.

In our yard, it has been as hot as 105 and as cold as -23. I grow a lot of Opuntias, a couple of Echinocereus, an Escobaria, and some Cylindropuntia in the ground; they have survived every winter and have bloomed yearly (except for the Cylindropuntia) since they got established. The majority of my collection is in a 8x10 foot greenhouse, where it stays through the winter--with a small Vornado heater set at about 40 degrees, where many get a small drink on a warmer day in mid-winter. I have a list of the cacti that need to be kept above 50 degrees, and I bring them into an unheated sunporch in the house for the winter.

I have hung shade cloth across the windows to cut down on the heat produced by solar effects during the summer, installed a strong exhaust fan at one end of the peak to pull out the hot air that has risen, and also use an oscillating fan to keep the air moving at the bench level. Unfortunately, the side window and the two vent window in the roof do not open wide enough to allow free circulation of air during the hottest weather. I bring most of the collection outside to the patio when the weather is good, but then I risk scorching the plants in the sun. We don't have any shade on the patio except just behind a trellis that effectively blocks much of the sun's rays. Oh yes, and I use plastic pots all the time except for when I need one that's deeper than it is wide to accommodate a large tap root or extensive root system, which is difficult to find in plastic. I've lost a great many cacti in clay pots--it's too porous for my needs, and when it comes time to repot, I find many of the roots have attached themselves to the inside walls seeking air and more moisture. These conditions define my cacti's environment, which is why I need information on correct watering for the genera/species.

[7george]

Astros and other small desert cacti listed above is hard to grow in northern climates without a real working greenhouse. Or these should be kept indoors with very careful end restricted watering. Literally just several times a season during the growing period. Astr. ornatum is little less rot prone bit that one has to reach bigger size to show first flowers. From South-american cacti Gymnos generally are not rot-prone but there is some difference between species because of different origin. Also Matucanas grow relatively easy too because of tropical origin but need lot of sunshine and temperature fluctuations, even those coming from lower elevations can be rot-prone and needing less water.