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Re: Some 1-2 month old Springbokvlakensis

Posted: Sun Jan 24, 2021 3:06 pm
by Terry S.
Photographs of the species taken in the wild do not appear to show any calcrete, so I am surprised at the suggestion that it is a calcicole. I wonder whether in this instance your acidic potting medium just needs a tad of upwards correction in pH? However, I often wonder how much calcium ion actually gets leached out of limestone chippings when used in this way, it must be negligible.

When people claim that their cacti from the Chihuahua Desert have done better after repotting into a mix contain limestone ships, I am inclined to think that the improvement was more due to fresh compost than anything else.

Re: Some 1-2 month old Springbokvlakensis

Posted: Sun Jan 24, 2021 5:25 pm
by el48tel
Terry S. wrote:
Sun Jan 24, 2021 3:06 pm
Photographs of the species taken in the wild do not appear to show any calcrete, so I am surprised at the suggestion that it is a calcicole. I wonder whether in this instance your acidic potting medium just needs a tad of upwards correction in pH? However, I often wonder how much calcium ion actually gets leached out of limestone chippings when used in this way, it must be negligible.

When people claim that their cacti from the Chihuahua Desert have done better after repotting into a mix contain limestone ships, I am inclined to think that the improvement was more due to fresh compost than anything else.
I find those thoughts of great interest and help. I have some tiny seedlings of Springbokvlakensis hybrids. I was considering a trip to the building merchants for some limestone chippings. Your comments have added to similar about mesembs supposedly growing in limestone but actually sitting in a bed of organic matter in a niche in a limestone outcrop. Am I now right in thinking, "leave alone"?

Re: Some 1-2 month old Springbokvlakensis

Posted: Sun Jan 24, 2021 5:46 pm
by ralphrmartin
I should slightly correct my remark, which was written in haste. I actually added crushed shells (sold as chicken grit), not limestone. It's relatively soft and also contains some dust, so perhaps more Ca ions become available than they would from a hard limestone.

I'd also add that it has helped greatly with H. koelmaniorum too.

My normal compost is an ericaceous mix (to suit my South American cacti), so this is my standard procedure for any plants needing some calcium.

Re: Some 1-2 month old Springbokvlakensis

Posted: Mon Jan 25, 2021 10:05 am
by el48tel
ralphrmartin wrote:
Sun Jan 24, 2021 5:46 pm
I should slightly correct my remark, which was written in haste. I actually added crushed shells (sold as chicken grit), not limestone. It's relatively soft and also contains some dust, so perhaps more Ca ions become available than they would from a hard limestone.

I'd also add that it has helped greatly with H. koelmaniorum too.

My normal compost is an ericaceous mix (to suit my South American cacti), so this is my standard procedure for any plants needing some calcium.
Wife might not miss a few ornamental shells from garden .... hopefully

Re: Some 1-2 month old Springbokvlakensis

Posted: Mon Jan 25, 2021 10:52 am
by NaZzAtAzEr
ralphrmartin wrote:
Sat Jan 23, 2021 5:30 pm
Let me give you a tip, which I got from Bill Hildyard. I found this species tricky to grow until he advised me that it likes limestone. I added some to the compost and as top dressing, and my plant is now doing really well.
Thank you for this tip, I'll try and source some limestone :D