When to get potted zone 10 seedlings inside?

[Hardypalms]

Hi

I have some zone 10 seedling pots. I m in zone 7b (Southeast USA) and they will first go in my unheated garage and then under grow lights.

I m not asking for each species but what safe low can they take outside?

Bentinckia condapanna

Kentiopsis oliviformis

Calyptrocalyx elegans (Z11?)

Syagrus schizophylla

Chamaedorea tepejilote

Thanks

Pat

 

[kinzyjr]

For these, I'd start bringing them in around the 40F mark in pots:

• Kentiopsis oliviformis
• Syagrus schizophylla
• Chamaedorea tepejilote

For the remainder, 50F-60F is probably a safer mark unless someone growing them has other guidance:

• Bentinckia condapanna
• Calyptrocalyx elegans (Z11?)

[Merlyn]

One easy way is to look up @kinzyjr's spreadsheet of cold damage data.  Take the temps at which it is reported as taking damage and add 10F for your "take it inside" temperature.  I'm just making a SWAG at the +10F number, because if it's a lot warmer in the unheated garage they might grow better there (with grow lights) instead of colder outside (with sunlight).  So for example Syagrus Schizophylla seems to take damage around 30F...so bringing it inside at 40F is probably safe.  Tepejilote is probably about the same, but my experience with Oliviformis is a few degrees more tender.  Calyptrocalyx Elegans only has one entry with death at 29F, and Bentinckia only has Nicobarica entries with death at 28.5 and 50% damage at 34. 

You can look up other reports in the Freeze Damage Data section: https://www.palmtalk.org/forum/forum/13-freeze-damage-data/

And the latest version of the spreadsheet is here:

 

[Jim in Los Altos]

Unheated garage? How cold will it be in there and for what duration of time? 

Edited September 11 by Jim in Los Altos

[Hardypalms]

54 minutes ago, Jim in Los Altos said:

Unheated garage? How cold will it be in there and for what duration of time? 

The cold garage gets down to 35 but they would never be there below 45.

I got grow lights. But people are saying here that they can take a lot lower than i thought.

Thxs

Pat

[Jim in Los Altos]

16 minutes ago, Hardypalms said:

The cold garage gets down to 35 but they would never be there below 45.

I got grow lights. But people are saying here that they can take a lot lower than i thought.

Thxs

Pat

As long as there’s some daytime warmth. Some of the palms on your list need warmth during the daytime hours or they may succumb to rot or other pathogens. Perhaps a heat mat under the pots would help. 

[Merlyn]

26 minutes ago, Jim in Los Altos said:

As long as there’s some daytime warmth. Some of the palms on your list need warmth during the daytime hours or they may succumb to rot or other pathogens. Perhaps a heat mat under the pots would help. 

Yeah I hadn't thought about that.  It's one reason I don't grow palms in pots.    The garage might not get as cold during the night, but unless you open the door during the day it might also stay cooler during the day.  In our swampy summer here in Floriduh it's usually hotter in the garage than outside.  But that might not be the case without a lot of solar load on the roof and an uninsulated attic over the garage.