Sclerocactus - to freeze & thaw or not to freeze & thaw

For the discussion of topics related to the conservation, cultivation, propagation and exhibition of cacti & other succulents.
Forum rules
For the discussion of topics related to the conservation, cultivation, propagation, exhibition & science of cacti & other succulents only.

Please respect all forum members opinions and if you can't make a civil reply, don't reply!
MaciejW
BCSS Member
Posts: 241
https://www.behance.net/kuchnie-warszawa
Joined: 25 Nov 2013
Branch: HERNE BAY
Country: England
Location: Kent

Sclerocactus - to freeze & thaw or not to freeze & thaw

Post by MaciejW »

Hi,
I have just got myself some Sclerocactus polyancistrus seeds which I am hoping to plant within month or two. I have read a lot about different methods of raising this cactus from a seed – freezing/ thawing cycles, freezing seeds before planting or just pre treatment of the seeds themselves with pricking off the shell of a seed. I can only assume that any of the methods would work, but my questions are:
1 – which one would guarantee the highest germination;
2- considering that any of them would end up with similar success rate of germination, whether any of them would produce plants that are healthier once growing/grown.
Do freezing/thawing cycles help in germination only or do they have impact on the survival rate of the plant itself?
Any comments much appreciated!
Ps.
Any recommended sources of Toumeya papyracantha seeds?
Patrick
BCSS Member
Posts: 1317
Joined: 20 Aug 2007
Branch: SOMERSET
Country: Portugal
Location: Alentejo, Portugal

Re: Sclerocactus - to freeze & thaw or not to freeze & thaw

Post by Patrick »

'Guarantee', 'germination' and 'Sclerocactus' don't really belong in the same sentence! It is a labour of love in my experience in which you shouldn't be too attached to the outcome. So I would say that both approaches will be very hit and miss. I always flick the end of the seed off with a needle. Then the fun only begins as the chances of getting them through to anything anybody would recognise as a plant are not enormous but worth the effort for those that do.
Patrick. Small varied collection of North American, Mexican and Andean Cacti. Variegated Agaves and Echeveria. Developing a succulent garden in Portugal. Joined Somerset BCSS and forum in 2007.
User avatar
iann
BCSS Member
Posts: 14562
Joined: 11 Jan 2007
Branch: MACCLESFIELD & EAST CHESHIRE
Country: UK
Role within the BCSS: Member

Re: Sclerocactus - to freeze & thaw or not to freeze & thaw

Post by iann »

I don't think you need to freeze Sclerocactus seeds and I don't think you'll have much luck germinating them in freezing conditions. Germinate them in warm to hot conditions. Germination is not that difficult, although you may have to dry out the pots and rewet once or twice before some of them will come up. There may be better ways since I haven't had anything like 100% germination, but freezing them isn't the answer.

Once they germinate, plan on them dying :) Some species are much more difficult than others but none of them are easy to grow on.
Cheshire, UK
PerG
BCSS Member
Posts: 23
Joined: 18 Nov 2012
Branch: None
Country: Denmark
Role within the BCSS: Member

Re: Sclerocactus - to freeze & thaw or not to freeze & thaw

Post by PerG »

It's not that I've had much success with Sclerocactus seeds. Not any to be honest. But this fall, I've sown some other winter hardy cacti, especially Austrocacti, with quite good germination rates "chipping" the seeds, like Patrick does. You might want to see this video: http://www.youtube.com/watch?v=MGG2-YpGDWA ("Germinating Sclerocactus seeds"). I cut the edge of the seed with a small scissor - don't know if it's the best method but I do think it's better than freezing. I have had Sclerocactus pots (and other hardy ones) overwinter in my unheated greenhouse with no success.
And yes, germination is one thing - survival another. If you're feeling up to yet another challenge, try grafting the seedling. I like to graft on Opuntias because their juice is sticky. So you can avoid putting a rubber band on a tiny Sclerocactus, I think you will squeeze it to death if you do so, or does anyone disagree?
As for sources of Toumeya seeds, there's SuccSeed: http://succseed.com/ or Hájek Kaktusy http://www.hajek-kaktusy.cz/en/semena/toumeya. I've only tried SuccSeed (and I can definitely recommend them) but Hájek must be mentioned here, since they have a good selection of Toumeya and Sclerocactus.
User avatar
Diane
BCSS Member
Posts: 5574
Joined: 15 Jun 2007
Branch: None
Country: UK
Role within the BCSS: Member

Re: Sclerocactus - to freeze & thaw or not to freeze & thaw

Post by Diane »

This is a thread I posted a few years ago, http://www.bcss.org.uk/foruma/viewtopic ... us#p153778, which shows some Sclerocacti I grew from seed, using the method of chipping the seed that Patrick mentioned. They were all grafted as small seedlings onto Trichocereus stocks (also young seedlings). They are still going strong, and appreciated being repotted last year. I found chipping to be the most successful method for germination, but nothing is guaranteed! Even using this method, don't expect to get many to germinate, and as Ian says, growing them on afterwards is exceedingly tricky.
Diane - member of Kingston branch

Growing cacti - balm to the soul!
Patrick
BCSS Member
Posts: 1317
Joined: 20 Aug 2007
Branch: SOMERSET
Country: Portugal
Location: Alentejo, Portugal

Re: Sclerocactus - to freeze & thaw or not to freeze & thaw

Post by Patrick »

Thank for pointing to the other thread Diane, I must have missed it first time round. Fantastic looking plants and some of them are the trickiest of the trickiest. I have some sclerocactus pubispinus on their own roots but have rather given up trying to grow sclero from seed apart from the scleros included in the NCL which aren't really sclero at all but Glandulicactus, Echinomastus and ancistrocactus.

I love them all but I've tried sclerocactus glaucus, parviflorus and spinosior as well as the pubispinus and although I got some germination most of them died a death at some point in the following year.
Patrick. Small varied collection of North American, Mexican and Andean Cacti. Variegated Agaves and Echeveria. Developing a succulent garden in Portugal. Joined Somerset BCSS and forum in 2007.
User avatar
iann
BCSS Member
Posts: 14562
Joined: 11 Jan 2007
Branch: MACCLESFIELD & EAST CHESHIRE
Country: UK
Role within the BCSS: Member

Re: Sclerocactus - to freeze & thaw or not to freeze & thaw

Post by iann »

S. spinosior from seed, photographed during the summer. I have three of these from maybe 10 seeds.
spinosior-0415.jpg
Here is S. cloverae with a companion that shows what happens so easily.
cloverae-0502.jpg
Cheshire, UK
User avatar
CactusFanDan
BCSS Member
Posts: 422
Joined: 13 Sep 2010
Branch: MANCHESTER
Country: England
Role within the BCSS: Member
Location: Manchester
Contact:

Re: Sclerocactus - to freeze & thaw or not to freeze & thaw

Post by CactusFanDan »

I'm trying Pedios and Scleros from seed soon. I asked on a facebook group with lots of experienced growers of the two genera and they suggested soaking the seeds in concentrated sulphuric acid (96%) for 8 minutes, then rinsing thoroughly and the sowing the seeds to get good results. Apparently 100% germination isn't uncommon with this treatment, but it's not for the faint hearted and I wouldn't suggest you do this without some basic chemistry knowledge. This method's probably less likely to damage the embryo than chipping the seeds.

Freeze-thaw cycles was another somewhat common suggestion and a number of people pointed me to Steve Brack's germination advice:
http://www.mesagarden.com/pedio.html
He just sows the seeds in Autumn and leaves them outside in all manner of New Mexico weather (which is probably far more ideal for their germination than we get in the UK).

Also, I think Succseed have Toumeya seeds in stock. I bought some from there a month or two ago. :smile:
-Dan
Growing an eclectic mix of Cacti, with a few Caudiciforms and other Succulents. Also interested in African bulb plants.
My C&S blog
User avatar
Phil_SK
Moderator
Posts: 5442
Joined: 11 Jan 2007
Branch: MACCLESFIELD & EAST CHESHIRE
Country: UK
Role within the BCSS: Forum Moderator
Location: Stockport, UK

Re: Sclerocactus - to freeze & thaw or not to freeze & thaw

Post by Phil_SK »

Have you handled conc sulfuric before? If you haven't, I'd advise you not to.
Phil Crewe, BCSS 38143. Mostly S. American cacti, esp. Lobivia, Sulcorebutia and little Opuntia
MaciejW
BCSS Member
Posts: 241
Joined: 25 Nov 2013
Branch: HERNE BAY
Country: England
Location: Kent

Re: Sclerocactus - to freeze & thaw or not to freeze & thaw

Post by MaciejW »

Thanks Patrick – I realize it might be tricky task.

iann– I wasn’t planning on raising them in freezing conditions but do it as a pre treatment to the seeds as per Steve Brack’s germination advice quoted above by Dan. Great plants – well done!

PerG – many thanks for your advice. I have seen that youtube upload before and was considering it as well. I am not huge fan of grafting though – I like my plants to be raised in a conditions as close to natural as possible and therefore – to look as similar to natural habitat plants as possible.

Thank you Diane – beautiful plants (tu)
CactusFanDan – thank you for referring to S Brack’s advice.

All together all mentioned above methods was what inspired me to ask for the advice and the 2 questions on my list – if freezing and thawing as per Steve Brack’s germination advice would result in plants being somewhat stronger and healthier once the germination process is complete (by saying complete I do not refer to the maximum percent germination success rate).
Post Reply