Astrophytum myriostigma soil

[willow]

Good morning all. I have a Myriostigma that I intend to give as a gift to brothers son. I have potted it into a soil mix which is made of John Innes 2 parts 2 parts very course grit, cat litter and crushed limestone , This I bought from Wicks and bashed up with a hammer to achieve smaller pieces. The soil is left over from a mix I made for my Ariocarpus plants who seem to be doing alright in it. I have read since that limestone must not be included in the substrate for astrophytums, nor must it be placed as a top dressing! I have not watered this plant yet as its not been repotted lond. Maybe give a small amount on Saturday which will be a week. This also includes a astrophytum capricorne!
Shall i repot without the limestone. Most grateful of any advice please.
Many thanks in advance
Willow

[iann]

It will be fine.

[adetheproducer]

All my astros have copious limestone chippings and are growing well especially my myriostigma loads of flowers and vegatative growth this season. You mix sounds good they should be ok in that for a long time if given rain water rather than tap water.

[Robb]

if given rain water rather than tap water.

Personally, I don't see the need for rainwater rather than tap water. I use it on all of my cacti and I get plenty of growth and flowers every season. On the other hand, Christchurch's water is quite different from most other cities/countries water (we get it from several aquifers.) How much of a difference that makes I don't know. Unless rainwater is easy to get without too much trouble I wouldn't worry about using it.

[DaveW]

Whatever water your plants grow well using it is OK. As Robb says though all tap waters are not created equal, some are far more alkaline than others, plus also contain added chemicals:-

http://www.dailymail.co.uk/health/artic ... water.html" onclick="window.open(this.href);return false;

http://martinwhitaker.co.uk/the-truth-a ... tap-water/" onclick="window.open(this.href);return false;

And the US is not exempt either:-

http://environment.about.com/od/waterpo ... _probe.htm" onclick="window.open(this.href);return false;

Plants are often sensitive to chemicals humans are not and vice versa. Even well waters can vary, which is why rainwater is often said to be best but these days is subject to industrial pollution in the form of acid rain etc. Even putting tap water through household water softeners adds sodium that can be detrimental to plants long term:-

https://www.rhs.org.uk/advice/profile?pid=691" onclick="window.open(this.href);return false;

http://homeguides.sfgate.com/watering-g ... 38688.html" onclick="window.open(this.href);return false;

[adetheproducer]

if given rain water rather than tap water.

Personally, I don't see the need for rainwater rather than tap water. I use it on all of my cacti and I get plenty of growth and flowers every season. On the other hand, Christchurch's water is quite different from most other cities/countries water (we get it from several aquifers.) How much of a difference that makes I don't know. Unless rainwater is easy to get without too much trouble I wouldn't worry about using it.

I do use tap water occasionally if I run out of collected rain water, it is quite soft in our area but I don't like the adding chlorine and if used long tern even though it is soft there is still some salts present which leads to increased repotting. The other good reason to use rain water is the dissolved carbon dioxide makes it slightly acidic which helps them grow. I even leave them out in the rain in summer on heavey downpours cant beat straight fom the sky.

[greenknight]

If the water just contains chlorine, not chloramine, just let it sit in an open container for 24 hours and the chlorine will dissipate into the air. You can add a small amount of vinegar to acidify the water. Fresh rainwater is the best, though.

[willow]

Thankyou all for the advice concerning the limestone chippings. I have to use rain water as I live in a hard water area, and it leaves horrible white chalky deposits
Thank you all Appreciated
Willow