Alstonia scholaris - low tenperature tolerance

[Philipp]

Hi all

I do have some seedlings of Alstonia scholaris and I was wondering if this species can survive nighttime temperature minima between -1°C and 0°C during winter or if they cannot handle temperatures bellow 10°C in general? Information I found online so far were not consitent. Would be an amazing fast growing rainforest tree.

Thanks a lot!

Philipp

[Than]

6 hours ago, Philipp said:

Hi all

I do have some seedlings of Alstonia scholaris and I was wondering if this species can survive nighttime temperature minima between -1°C and 0°C during winter or if they cannot handle temperatures bellow 10°C in general? Information I found online so far were not consitent. Would be an amazing fast growing rainforest tree.

Thanks a lot!

Philipp

Wow, I have been looking for this species for a long time! Would you mind sharing the name of the seller?

Re your question, I am not sure but I'd guess -1C is a bit too cold for this tree. It also depends on duration, and the maximum temperatures next day.

[Philipp]

Here they are: https://www.rarepalmseeds.com/alstonia-scholaris they had a nice germination rate, just needed a bit as much as I remember. Still places in a warm and humkd greenhouse. They grow super fast

During the day, temps go up usually to 5-10C and the low temp is always only very short during the night. I gave one to the Botanical Garden of Brisago Islands in Ticino, Switzerland. There it should be frost free in general. Wondering how they (including other plants such as Avicennia marina etc.) will develop there

Cheers,

Philipp

[Than]

Excellent. I doubt it will survive anywhere in Europe but worth a try anyway. What medium did you use for the seeds?

Let's wait to see if anyone here grows it. 

[Philipp]

There are Plumeria growing on Crete, in Cyprus and coastal Spain so I guess they should grow there. Probably just with a problematic water consumption.

I am growing everything in coconut fibre and/or perlite to avoid fungal infections etc.

[Than]

2 hours ago, Philipp said:

There are Plumeria growing on Crete, in Cyprus and coastal Spain so I guess they should grow there. Probably just with a problematic water consumption.

I am growing everything in coconut fibre and/or perlite to avoid fungal infections etc.

True, plenty of plumerias here.. 

[tropicbreeze]

You have the seedlings already so you're going to find out. But I wouldn't hold out much hope. Rare dips down to freezing may not be the critical issue. It's more a question of how long the cold periods last. You mentioned, "During the day, temps go up usually to 5-10C and the low temp is always only very short during the night." For tropical plants day temps of 5 to 10C are way down.  The natural occurrence of A scholaris is also where Coconuts grow. That might give you a better idea of their temperature range.

I have some A scholaris, and also A. actinophylla. The main scholaris is about 25 metres tall, with a number of volunteers of various sizes. It was on the place when I bought it and was already a fair size. The actinophylla is native here so there's lots of them around. So good luck with them, but don't get your hopes too high. You've picked a very big challenge.

Avicennia marina ssp. australasica is the southernmost growing mangrove but it grows in the sea (tidal). One of the best moderators of climate is the sea.

[Than]

2 hours ago, tropicbreeze said:

You have the seedlings already so you're going to find out. But I wouldn't hold out much hope. Rare dips down to freezing may not be the critical issue. It's more a question of how long the cold periods last. You mentioned, "During the day, temps go up usually to 5-10C and the low temp is always only very short during the night." For tropical plants day temps of 5 to 10C are way down.  The natural occurrence of A scholaris is also where Coconuts grow. That might give you a better idea of their temperature range.

I have some A scholaris, and also A. actinophylla. The main scholaris is about 25 metres tall, with a number of volunteers of various sizes. It was on the place when I bought it and was already a fair size. The actinophylla is native here so there's lots of them around. So good luck with them, but don't get your hopes too high. You've picked a very big challenge.

Avicennia marina ssp. australasica is the southernmost growing mangrove but it grows in the sea (tidal). One of the best moderators of climate is the sea.

Great advice. Re the maxima, I still haven't reached a conclusion about their effect in overcoming a cold night minimum. I mean, will a maximum of 15C help a plant recover from a night of 0C more than a maximum of 10C will, or it doesn't really matter? My gut instinct says that a tropical or semi-tropical plant may survive a cold night if next day is warm enough, however, from some statistics I have seen, there doesn't seem to be a big difference between areas that get warmer during day and those that don't (let's say they have the same minimum temperatures). I wonder if there is some study on this topic.

[tropicbreeze]

I don't know of any studies done on that issue. My personal view on plants that experience a short extremely cold spike need the temps to quickly get back up over say 25C, preferably 30+C. But plants do differ in their requirements so it would vary a bit by species.

[Than]

7 hours ago, tropicbreeze said:

I don't know of any studies done on that issue. My personal view on plants that experience a short extremely cold spike need the temps to quickly get back up over say 25C, preferably 30+C. But plants do differ in their requirements so it would vary a bit by species.

There aren't many places in the world where 0 C is followed by 25-30 C so quickly. Here it will be followed by 15C if we are lucky,

I remember coconut trees surviving several days of 6-7C in northern India for 3 weeks in January, followed by a February which was already above 25 C. 

[tropicbreeze]

Here we (rarely) can get a spike down to 10C but daytime gets up into the low to mid 30's. Coldest time is just before dawn but when the sun does rise the temperature goes up rapidly. It happens with very dry air which will lose a lot of heat overnight but reheats rapidly in the sun. When the air is humid there's a lot of lag in temperature change, not so low and not so high.

I read some time ago about places in India which were sheltered by mountains and had coconuts growing where you wouldn't expect them.