During late flower, is there a point where humidity can be too low?

[TomH]

I’m in week 9 two different plants, both look like they want to go at least 11 or 12.
Today we have a north-east wind! The arid direction, I have outside humidity in the teens, my shed and tent are in the upper 20% (26% to 29%).

Is that too dry for plants to properly grow in week 9 of flower?
Temps are in the upper 60s to low 70s (68f to 72f).

Do I need to turn on my doggone humidifier again?

 

[TomH]

I think I have the temp stable at 65f, RH 30%.
Looks like it’s at the high line of the chart, hopefully remaining comfortable for the trichomes.

 

[Pipecarver]

I think I have the temp stable at 65f, RH 30%.
Looks like it’s at the high line of the chart, hopefully remaining comfortable for the trichomes.

I just finished a flower period at 35-40% and they loved it, I don't think 30% would do harm...Granny could answer that I believe.

 

[MDK]

I've ran some pretty low humidity, definitely beats the shit outta higher humidity lol for me atleast ain't grown any sativas...yet

I think when you get super low the risk of critters increases...certain mites spider mites maybe can't recall ..would make sense though as everything around it is bone dry they move in on a supple plant

 

[freezeland]

If the vpd is 1.6 or higher the plants are over transpiring and will dry out. What is the vpd? I would recommend you use leaf vice ambient temp for your calculation.

 

[TomH]

If the vpd is 1.6 or higher the plants are over transpiring and will dry out. What is the vpd? I would recommend you use leaf vice ambient temp for your calculation.

I can only estimate leaf temps, but I’m riding the line around 1.40 - 1.50.
The heat and humidity aren‘t flat lines, more of small sine waves. When they vary throughout the day, it gets close to 1.60

 

[MDK]

I've hit 1.9 just had to water more often with lighter doses of feed

 

[freezeland]

I can only estimate leaf temps, but I’m riding the line around 1.40 - 1.50.
The heat and humidity aren‘t flat lines, more of small sine waves. When they vary throughout the day, it gets close to 1.60

You should be all right then. A IR thermometer is one of the best tools to have indoors.

 

[Pipecarver]

I've ran some pretty low humidity, definitely beats the shit outta higher humidity lol for me atleast ain't grown any sativas...yet

I think when you get super low the risk of critters increases...certain mites spider mites maybe can't recall ..would make sense though as everything around it is bone dry they move in on a supple plant

not for me, when the humidity is low here its in the 0 - -10 c ish, critters don't stand a chance, I've more critter problems with high humidity and high heat, The S.M. critters can like me in July Aug Sept, I try to bleach my floor once a week to slow down their march towards my plants..