E. pachypodioides germination help

[Phlempton]

Hi

Anyone got any experience with Euphorbia pachypodioides?

I've got a couple of seeds left but I'm not really sure how to go about germinating them.

The only succulents I've had experience with (growing from seed) are a number of Pachypodiums, Adeniums, and Dorstenia foetida...all of which I had good success with.

I just tried to germinate 8 out of 10 of my E. pachypodioides seeds in the same way I did for the above mentioned seeds, but unfortunately after 3 weeks it would seem I've had no luck.

So I've got two left.

How should I go about it?

The method I tried and failed with was as follows: I just laid out the seeds on the fine mineral based medium, sprinkled a small amount of sand over each of the seeds, misted, and then put the dome on. I then left it on my desk in my room, opening daily for airflow, etc. Temps ranged from a regulated minimum of 20C/68F at night to 25-35C/77-95F max during the day depending on the weather.

Now after three weeks, 3 of the 8 seeds have gone black, so Im assuming they're rotting away. But the rest are still light brown colour and plump. Any chance they're still viable?

Thanks

[One Windowsill]

Hi!

I have no experience with that species. However, are the temperatures you quote the air temperature around it? Gardeners often talk of "bottom heat" when talking about germination, because it makes a difference. The substrate may not get up to air temperature because of cooling by evaporation. Heat mats are the ideal but can you put it on something mildly warm?

The plant is only found in the very northernmost tip of Madagascar, nicely tropical. 20°C is the very lowest temperature it would ever encounter. I would raise the temperature a bit, 27 to 32°C.

I would give seeds a good drench, rather than lightly misting them, as more water can wash away germination inhibitors that many seeds have to prevent them germinating due to a brief rain shower. That may not be the problem here.

Climate of Northern Madagascar:
https://www.climatestotravel.com/climat ... ntsiranana

[Jangaudi]

hmmm, temperature is about right, but it's probably safer to sterilise the growing medium, and give the seeds a diluted bleachbath, and keep them sealed in high humidity for a while. It's a standard procedure for cacti (baggy or container method), but I tried several times with Euphorbia seeds and it works well also. One thing though, is that Euphorbia seeds don't stay viable very long, hope they are fresh. Also don't know how much sand you put over the seeds, but they generally need light to germinate, so don't cover them. Another trick that could increase the germination, is give the seeds that are still in one piece, a little bleachbath (diluted), it breaks down the outer barier a bit, and I got success doing so with several species. In general Euphorbia seeds are a little hard to germinate, I usually only get less than 50% germination rate.

[Phlempton]

Thanks for the help!!!

Hi!

I have no experience with that species. However, are the temperatures you quote the air temperature around it? Gardeners often talk of "bottom heat" when talking about germination, because it makes a difference. The substrate may not get up to air temperature because of cooling by evaporation. Heat mats are the ideal but can you put it on something mildly warm?

The plant is only found in the very northernmost tip of Madagascar, nicely tropical. 20°C is the very lowest temperature it would ever encounter. I would raise the temperature a bit, 27 to 32°C.

I would give seeds a good drench, rather than lightly misting them, as more water can wash away germination inhibitors that many seeds have to prevent them germinating due to a brief rain shower. That may not be the problem here.

Climate of Northern Madagascar:
https://www.climatestotravel.com/climat ... ntsiranana

Yes, I'm referring to the air temperature around it. And yes I too was wondering if that was the problem.

Thus, about 5 or 6 days ago I put the humidity dome with the remaining nice looking seeds directly on top of the radiant oil heater in my room (well, on top of a folded towel on top of the heater) which is on just about 24/7. I tested it for a day first and the temperature in the dome sits at a steady 29-31C all day and night and provides a nice steady bottom warmth just like a heat mat. So far the change hasn't helped any of the old seeds gemrinate but I'll keep them there until they dont look viable anymore.

And my "misting" is probably a little more that a true misting to be fair. They definitely get well and truly wet enough I suspect.

When I try my last two seeds I'll stick them on the heater from the start and hopefully that'll do the trick.

hmmm, temperature is about right, but it's probably safer to sterilise the growing medium, and give the seeds a diluted bleachbath, and keep them sealed in high humidity for a while. It's a standard procedure for cacti (baggy or container method), but I tried several times with Euphorbia seeds and it works well also. One thing though, is that Euphorbia seeds don't stay viable very long, hope they are fresh. Also don't know how much sand you put over the seeds, but they generally need light to germinate, so don't cover them. Another trick that could increase the germination, is give the seeds that are still in one piece, a little bleachbath (diluted), it breaks down the outer barier a bit, and I got success doing so with several species. In general Euphorbia seeds are a little hard to germinate, I usually only get less than 50% germination rate.

Temps do seem right but I think One Windowsill makes a good point in that the medium will be a lower temp due to evaporation and other factors so that 20C minimum might be 15C to the seeds and rhats probably not good.

I did actually sterilize the medium, but yeah I didnt bleach bath the seeds. I considered it, but couldnt find and info on it directly related to this species so I didnt. Guess I should have.

Sand covering was as minimal as it gets. The seeds stick out of it. Like when I initially put the sand on it covers them, and then the first time I mist/spray them it pushes the sand away and exposes the seed. I just do it as it help keep small seeds in place and makes it easier to see them to see their progress.

How strong does the light need to be? When I had them on the desk they were directly under a fluro tube I use for germinating seess and seedlings, but niw I've moved the humidity dome to the heater about 5ft away where its probably only getting 5% of the previous light. Do I need more?

As to how fresh the seeds are I don't know. I have bought a range of seeds from this vendor and have had mixed results. Some species were clearly older and had low to non-existant germination rates while others were okay at 50-75%.


Anyways thanks again.

Im thinking I'll bleach bath them and then pop them on the heater from day one and then just cross my fingers and hopefully I can get 1 out of the 2 remaining.

[Jangaudi]

There's a guide here on sowing Euphorbias where it says that "especially madagascar Euporbias need to be sown within weeks" because of short viability. But you never know . https://www.euphorbia-international.org ... sample.pdf

[Phlempton]

There's a guide here on sowing Euphorbias where it says that "especially madagascar Euporbias need to be sown within weeks" because of short viability. But you never know . https://www.euphorbia-international.org ... sample.pdf

Weeks. Hmmm. That'll do it. That'll be the reason I suspect.

Literally took longer than that to get to me in the post, lol, sigh.

[RorBurg56]

I have had some success germinating euphorbia seed of questionable age by adding freshly burnt singed bark and tea to the hot water soak and by adding a light layer of this par-burnt material just below the medium surface. The reason being that compounds released by burning can help break dormancy of many plant seeds, even those not preadapted to a fire intensive ecosystem. This said I have certainly no real statistics of my own to verify that this helps, just that I get better germination with it now than I used to when not using it.

[One Windowsill]

The reason being that compounds released by burning can help break dormancy of many plant seeds, even those not preadapted to a fire intensive ecosystem.

That is rather interesting considering this article I read a few days ago:

"Why would a plant that doesn’t live in a wildfire zone need to be able to smell smoke?"
https://www.botany.one/2022/02/why-woul ... ell-smoke/

Hangovers from the Carboniferous?

[Phlempton]

Hmmm. I've done smoke water tratments on a few Australian natives before but I never even considered it in this situation.

But your anecdotal evidence RorBurg56, along with that article from One Windowsill, is enough for me to try it at this point.

I actually already got them started late last night, but I'll go and make some smoke and then use that to mist them down from now on. Cant hurt.

Of those two seeds I put in last night, already one looks good and the other doesnt look great. One has swelled up nicely with a nice tan brown colour, while the other hasnt swelled as much and is a much darker brown. So I'm guessing its all down to one remaining viable seed. Fancy my chances? I dont. Lol. Sigh.

[One Windowsill]

Fancy my chances? I dont. Lol. Sigh.

Good luck!