Soil Temperatures for Palms to Resume Growth?

[chinandega81]

What soil temperature at say around 6 inches is needed for palms to "wake up" from their winter hibernation and to resume growth (and be able to green up and take in more water and fertilizer? 

[mnorell]

Palms don't go dormant for the winter the way dicot trees or shrubs do, they just slow down or stop growing due to environmental factors of temperature, daylength, rainfall, etc. Many palms are naturally adapted to a cooler or warmer overall environment, high elevation palms are accustomed to cool nights, the opposite for lowland tropicals; and thus some will grow well during winter in south Florida, others will slow down. So it's more a matter of "what species are you growing" to give an answer to your question.

[ShadyDan]

All my palms have been growing (albeit very slowly) during the winter here in the PNW with short days and cool soils. Average highs lately have been 5-10 C, with lows around 0-5C. Some palms, like Windmills, actually can put on decent growth throughout the winter. 
 

As mentioned, palms don’t go dormant so they are awake all winter long! 

[Bazza]

I noticed the spears aren't shooting out on my Archies as they do during the warm season. But they are still growing - just not as fast.

But your point about soil temperature influencing growth rate is on point. The night temps have a huge impact of plant growth. Get the night temps back up and the rest will come.....

[mnorell]

I think we all find ourselves realizing after being cognizant of this situation that some palms are going to suffer through our winters but grow like gangbusters in summer, others will enjoy winter and suffer through the summers. And then there are the goldilocks species that excel in springtime, but put up with the chill of winter and the heat of summer. Maybe the latter type stands the best year-round chance since there is less swing on either side, but for us growing palms, probably the secret to happiness is having a nice balance of all of the above for your own climate...that way you will never go through the "boring season"! And Bazza is right about night temperatures, since that's when palms do their growing; but in that regard one still has to know the "sweet spot" for each species, since it varies depending on their natural environment.

[sonoranfans]

I think its the soil microbes that go dormant.  The soil microbes are needed to uptake nutrients(they convert ammonia to usable nitrogen for example).  This paper measures bacteria respiratory activity at 70-120x higher at 45C than at 0C.  There is a nice graph tha shows you it begins to increases above 10C and mor e rapidly at about 20C.  Looks like 20C is a good activity   https://academic.oup.com/femsec/article/52/1/49/483427  Your plants will need those microbes to convert the fertilizer to usable nitrigen.  So throwing down fertilizer in winter is going to be wasteful and since NPK has some minor heavy metal content that can accumulate, it makes little sense environmentally.