Gill, I've had that happen as well. Not really sure how to prevent that leaching up the caudex. I think it really has more to do with a nutrient rich soil that's mixed in (say peat or other organic matter) that the color is sucked out when watered. I just assume that an occasional watering on the caudex will kind of wash it off. Perhaps even get sun bleached over time.

I haven't really worried about it but think if it's doing that then it's possible that eventually it could get a salt build up unless a good heavy watering to flush it out once in a while is done.

I guess I look at it like this. When you raise the roots out of the dirt at each repotting and are left with that very exposed and blonde color that over time it will go away with exposure. So perhaps the same can be said with that water leaching stain. I'm just speculating. But now you've kind of got my mild OCD stirring and I think I shall spend some time researching the internet. LOL

Kirk

I'm not really into full watering mode at the mo as they're still leafing out. In the real growing season I fertilise weekly and on the first watering of each month I hold them under the tap and just let it run through, hoping to wash out excess salts from the tap water and fert. Not being used to having them outside with the chance of rain washing it off, I was wary of watering the caudex heavily.
Gill from the UK.

Gill, unpot it and use a soft brush and clean with water and see if it goes away.

Marie

Hi Marie, they're not that bad now thanks as I washed/dabbed them lightly with a wet cloth. It will soon be time for their annual re-pot and up-lift so I'll try the wash and brush up method then.
Gill from the UK.