I've been growing now for a number of years, and have some good data to share. Last year I had a very below average winter exposing my plants to 28F (-2C) for a couple of hours. Most of my winters bottom out around 31F(0c) - 34F (1c) I think it will also be useful to denote there are 2 types of cold events here in the tropics. There is radiative cooling which occurs from cool air radiating down the ground level. The other kind is an advective event where it is primarily wind driven cool air that makes the temps the same at ground level and tree top level. Advective cooling is devastatingly worse than radiative. When radiative cooling occurs microclimates have more of a chance to protect plants with bodies of water and canopy coverage. The only way to protect plants in an advective event is if you protect the plants from wind. I will go more into this later. Other factors include if the cold comes with rain. Sometimes moisture at lower temps leads to bad fungus forming that can kill a plant. Important post-freeze care depends a lot on what your temps will look like after the freeze, my climate has these cold events for 2-3 days then its back to 80F, so after a bad cold event I have been taught to give a dose of copper fungicide, slow release fertilizer and a foilar fertilizer spray. I've only done this for coconuts, but it could be beneficial for other plants.


Psychotria Viridis - cold hardy down to 31F with minimal damage, 28f (covered) defoilated completely, ones deeper in my jungle did better.

Psychotria Nexus - Cold Hardy down to 31f with no damage, 28f (covered) minimal damage

Bansteriopsis Caapi - Cold hardy down to 31f with minimal damage (leaf purpleing), 28F destroyed the top 75% of the vine, it grew back most of its mass in a single season. (unprotected) pic 3

Banisteropsis Muricata - Cold Hardy down to 31f with minimal damage, 28f completely defoilated, came back. (unprotected) pic 7

Acacia Confusa - Coldest seen 28f (not covered) no damage apparent (unprotected) pic 5

Mimosa Hostillis - Coldest seen 28F, protected from wind some damage, unprotected from wind total death. The one I had protected from the wind survived with no issues while the one not protected died completely and never came back.

Trichocereus (all species) - 28f no damage (unprotected)

Iboga - Coldest tested 40f, some plants showed damage most did not. (greenhouse)

Kava - seems to die consistently below 50F (greenhouse)

Kratom - 28F defoilated completely, grew back almost entire mass in one season. (unprotected) pic 6

V. Africana - 28f mostly defoilated, came back (unprotected) pic 1

Tabernaemontana Undulata - 28F completely defoilated, came back. (unprotected) pic 1

Tabernaemontana Sanaho? - 40f Died completely (greenhouse)

Yopo - 28F no damage seen (unprotected) pic 2

Vilca - 28f no damage seen (unprotected)

Hawaiian baby wood rose - damage noticed below 50F

Chaliponga - Coldest seen 40F some minimal damage (greenhouse)

Erythroxylum Novogranatense
- Cold hardy down to 31f with minimal damage. 28F defoilated 75% of the plant. (unprotected?) pic 4

Salvia Divinorum - 28F wrecked the plants but most recovered. (open greenhouse in the jungle)

Thanks musk...


Bookmarked for reference

Thanks Musk.

Those US climates! It's crazy that you can get a frost one night, and the temps can creep up to 80F the next day. Where I am, nights are not much different to days, and sometimes a night is warmer than the day that follows.

My climate is much colder than yours. I can still attest that cacti are quite hardy.
Of course when they're dry it's a different story, they can take -12C (10F). But in the more realistic setting of growing them outside in the ground and exposed to the rain and slugs, they can still take a good amount of frost.

Here is some data from me:

* T. peruvianus wet: -6C (21F) - no damage whatsoever
* T. pachanoi wet: -2C (28F) - no damage, -6C (21F) - younger, softer stems turned to mush, older stems intact
* T. bridgesii: like T. pachanoi
* Acacia floribunda: -2C (28F) - no damage
* Phalaris aquatica: no damage at -6C (21F) for me; someone else has had no damage at -12C (10F)
* B. caapi var caupuri with a small plastic canopy above it: 0C (32F) - no damage and holding on to leaves; -2C (28F) - completely defoliated

I am about to move somewhere a lot colder than anywhere I have lived before.
Does anyone know the cold tolerances for lophophoria or catha edulis

Catha edulis was not happy living in Northern England, neither on a windowsill indoors nor outside in a greenhouse. IIRC, it died below about 5°C. I think it would need lights and heating.

My Lophs are doing OK on a windowsill in Northern Germany, they flower quite abundantly during summer. Temps get low but they don't freeze.

MH - your work here encourages me to add a few more of these tropical plants to my collection. Thanks for sharing.

Another data point, echoing Jagube - I already reported that P. aquatica was fine after being frozen solid in a block of ice for three weeks, with temperatures down to -12°C.

Awesome guys,

would be great to make those infos somewhere sticky in the wiki or somewhere else.
There is also a great pile of collected info regarding temperature hardiness over at share the seeds.

Would be great if we could interweave those information to one big table somewhere.

http://sharetheseeds.me/forum/index.php?topic=919.0

How do you guys measure the coldest temp? Are there thermometer which lock the coldest temp which they measured over a period of time?

I will collect the data over the next days. can someone put it in the wiki?

Yes, there are min max thermometers, both digital and analog. Another option is getting a basic wireless weather station, so you can store the readings online / on the computer and analyze them, draw graphs etc.

If you live in a populated area, the nearest weather station should be close enough to give you a good approximation. There are also amateur weather station networks like NetAtmo ( map at https://weathermap.netatmo.com/ ), which shows min and max temps. Not all stations are reliable, but there is enough of them to allow you to draw your conclusions.

In Portugal, usda zone 8
The outdoor pachanoi roted black in the middle top of their head ; Temps min -2° at night so far (could go to -7° later in winter), and really wet weather.
I hope it doesn't evolve too bad , i got only 1 in the ground , the others in pot in the greenhouse; but i"m gonna quickly run out of space.

I think thermometers might be the best solution.
I discovered that temperature can variate within a 100 meters or less because of a river or some buildings. But a weather station is better than nothing. I found a station 2 blocks away. Nice webpage!