FlytrapCare Carnivorous Plant Forums

Hi,

I was reading here on the forums about Cold Strat for Sarr seeds. I do have a question however that I couldn't find here on the forum. My question is is as follows. Can you kill seeds if it gets too cold? Like can you stratify them in the fridge freezer?

Hope someone answers, Thanks!

Jonathan

Good question. I stratify some seeds outdoors during the winter and let them wake up naturally so I doubt if a freeze would kill them but I don't know about a 6 week continuous freeze. I wouldnt try it.

A good question indeed. I have on occasion accidentally frozen some seeds in their growing pots during stratification, which didn't seem to reduce the germination rate too much, but that was only for a short period of a few days, rather than a prolonged period. The perceived wisdom is that they shouldn't be frozen at all, but how detrimental it is I really don't know, as Purpurea seeds in the wild often get frozen, especially in Canada, Switzeland and Ireland and they certainly germinate and grow OK, and they are the same genus. I suspect that Purpureas and their hybrids would be more tolerant to freezing than other species. I will try it next year with some open pollinated mongrels.
Cheers
Steve

steve booth wrote: I suspect that Purpureas and their hybrids would be more tolerant to freezing than other species.

I was thinking the same.

Considering they are found in Canada (or at leas the ssp.), that seems correct to me.

This would be interesting to try out and see the results. It may be possible that the seeds would be killed, or significantly damaged if they froze quickly (i.e. placing warm, moist seeds directly into the freezer) forming ice crystals within the cells causing them to rupture. Although, that doesn't always happen. In the wild the seeds would likely be insulated from these extreme temperature swings in some form or another (e.g. snow, water, Sphagnum, etc.). If they were slowly brought to a freezing point and kept there for the period of the stratification, it may work in certain species and subspecies (like already mentioned).

I am asking because I am afraid my crisper may be too cold for germination. What is the ideal cold strat temp for Sarr seeds?

I strat mine at fridge temps...around 35F.

Thanks for all the answers guys!

Dionae wrote:I strat mine at fridge temps...around 35F.

What is that in Celsius?

How long should it take for them to start to germinate?

Hi Johnathon

35F is 1.6 C but anything from 3 -10C should do the trick.
Once you've stratified them for our weeks or so (wet stratification) they take anything from 2 weeks to a year to start germinating dependent on conditions so don't give up on them. They do better if, when you have placed them on the surface of your medium, you give them some gentle bottom heat via a heat mat or propagator, that gets them going quicker and increases speed of growth.

Cheers
Steve