Grafted Ariocarpus cultivation question

[zagoric]

If the watering needs for Ariocarpus fissuratus say they are semi-dormant in summer and watering should be stopped after flowering (in November), does this remain true if grafted on Harrisia jusbertii (or another stock)?

Thanks.

[esp_imaging]

You need to keep the stock healthy, so it will need more water than an Ariocarpus on its own roots. Harrisia should be happy with a cool, dormant winter with little water, but may need rather more water in the summer or need to be kept shadier and cooler than an own-roots Ariocarpus would tolerate.

[zagoric]

Does this hold true for hardiness? The whole plant is as hardy as the stock?

[esp_imaging]

Does this hold true for hardiness? The whole plant is as hardy as the stock?

No, the grafted combination is only as hardy as the least-hardy part. Harrisia can survive light freezes if totally dry, A. fissuratus is rather hardier, if totally dry, so if you are planning on keeping it really cold, the Harrisia may suffer more than the scion.

[zagoric]

Okay, that's what I always assumed, but it's good to know for sure.

I'm in Los Angeles, so it should not be much of a problem for either of these two species, but it's better to know than guess.

Thanks again.