when is cold too cold?

Do you think 55-60 is too cold for flower?

  • Yes

    Votes: 32 74.4%

  • No

    Votes: 11 25.6%
  • Total voters
    43
since1991

since1991

Well-Known Member
If this is the cats preferred style of growing he obviously has cold resistant cultivars in his line up. Should breed that stuff into the stock. Many outdoor growers do this. Selecting and what not. Just goes to show how tolerant cannabis is and can be with selective breeding practices. I myself found out long ago that cold temps slow growth to a crawl. Purple sickly stems and slow new growth. They have a hard time taking in what they need when temps fall below 60 degrees.....for me anyways. In the winter ia always bust out my small space heater in the basement and plug her in to my master timer. Kicks on when lights go off. Keeps it a nice 70 degrees consistently. With certain varieties i kick it up to 75 degrees. I like to keep a lights on lights off temp differential of no more than + - 10 degrees. Sometimes 5. Its an old greenhouse tomato/vegetable grower trick and it minimizes bolting and lanky stretch when initiating a flowering photoperiod.
 
420monster

420monster

Well-Known Member
So can we all agree below 50 is to cold and call it quits since the title says when is to cold cold not what is optional or what temps get the biggest yeild colors ect ect everyone grows there own way just as some prefer led to hid

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oldbikepunk

oldbikepunk

Well-Known Member
Heat pads in cold grows can change all that. The lights keep it warm when they're on, but the floor is always too cold in winter. You could even run the heat pads on a timer for the 'night-time' hours when the lights are off. I have night times of 64 and highs of 78-80 with lights on. Where plants are on concrete it is helpful to use heat pads.
 
C

Connoisseurus Rex

Well-Known Member
oldbikepunk said:
Heat pads in cold grows can change all that. The lights keep it warm when they're on, but the floor is always too cold in winter. You could even run the heat pads on a timer for the 'night-time' hours when the lights are off. I have night times of 64 and highs of 78-80 with lights on. Where plants are on concrete it is helpful to use heat pads.
Click to expand...
Water on the floor is my biggest concern there. I use polystyrene or styrofoam insulation.
 
diamonddav

diamonddav

Well-Known Member
wow anyone else notice that the o.p. of this thread hasn't said a thing and you guys argued for almost a week!! good points tho! I think were all having a bit of trouble with lights off temps this year due to the cold weather! personally I think its better to give advice on what you do to remedy the situation than try to convert ones growing style..... TO EACH TERE OWN! arguing gets no one nice buds in the end! but carry on , ive got weed and popcorn for the show:lol:
 
since1991

since1991

Well-Known Member
Space heater on when lights are off has been my remedy for years. Set at about 68 to 72 degrees. On fer the full 12 hours of night night. Easy enough. Shouldn't really even be a question to be honest. This is simple growroom dialage in my opinion.
 
Budget Buds

Budget Buds

Well-Known Member
I'd say it depends alot on what kind of cannabis it is, a sativa or sativa dominate cross will be less tolerant of cold temps as opposed to a pure indica or dominate indica cross, I've had snow on my pure afghani's and all they did was turn a pretty purple and a few dying sun leaves. Indoors I keep my room around 68 because thats what i set my house at and never had an issue. I do not dabble with sativa or majority crosses ::) BB
 
since1991

since1991

Well-Known Member
I agree. And another huge factor is where your at climate wise on this planet growing plants. Outdoors this is a given....indoors this is true also for the majority of us whose indoor setups climates change however minor with the seasons outdoors. Most dont have the coin or ablility to invest in a truly seperate growgrow indoors in a completely self contained and controllable environment. We can get close. But to do it no matter what the weather is outside and it not playing any factor cost money.
 
Resinhound

Resinhound

Well-Known Member
For those of us who dont think temperature affects c02 uptake.

JournalPhysiology and Molecular Biology of Plants
Publisher Springer India
ISSN 0971-5894 (Print) 0974-0430 (Online)
Issue Volume 14, Number 4 / October, 2008
Category Research Article
DOI 10.1007/s12298-008-0027-x
Pages 299-306
Subject Collection Biomedical and Life Sciences
SpringerLink Date Thursday, February 26, 2009

Suman Chandra1 , Hemant Lata1, Ikhlas A. Khan1, 2 and Mahmoud A. Elsohly1, 3

(1) National Center for Natural Product Research, School of Pharmacy, University of Mississippi, Oxford, MS-38677, USA
(2) Department of Pharmacognosy, University of Mississippi, MS-38677 Oxford, USA
(3) Department of Pharmaceutics, School of Pharmacy, University of Mississippi, University, Oxford, MS 38677, USA

Published online: 26 February 2009

Abstract Effect of different photosynthetic photon flux densities (0, 500, 1000, 1500 and 2000 μmol m−2s−1), temperatures (20, 25, 30, 35 and 40 °C) and CO2 concentrations (250, 350, 450, 550, 650 and 750 μmol mol−1) on gas and water vapour exchange characteristics of Cannabis sativa L. were studied to determine the suitable and efficient environmental conditions for its indoor mass cultivation for pharmaceutical uses. The rate of photosynthesis (PN) and water use efficiency (WUE) of Cannabis sativa increased with photosynthetic photon flux densities (PPFD) at the lower temperatures (20–25 °C). At 30 °C, PN and WUE increased only up to 1500 μmol m−2s−1 PPFD and decreased at higher light levels. The maximum rate of photosynthesis (PN max) was observed at 30 °C and under 1500 μmol m−2s−1 PPFD. The rate of transpiration (E) responded positively to increased PPFD and temperature up to the highest levels tested (2000 μmol m−2s−1 and 40 °C). Similar to E, leaf stomatal conductance (gs) also increased with PPFD irrespective of temperature. However, gs increased with temperature up to 30 °C only. Temperature above 30 °C had an adverse effect on gs in this species. Overall, high temperature and high PPFD showed an adverse effect on PN and WUE. A continuous decrease in intercellular CO2 concentration (Ci) and therefore, in the ratio of intercellular CO2 to ambient CO2 concentration (Ci/Ca) was observed with the increase in temperature and PPFD. However, the decrease was less pronounced at light intensities above 1500 μmol m−2s−1. In view of these results, temperature and light optima for photosynthesis was concluded to be at 25–30 °C and ∼1500 μmol m−2s−1 respectively. Furthermore, plants were also exposed to different concentrations of CO2 (250, 350, 450, 550, 650 and 750 μmol mol−1) under optimum PPFD and temperature conditions to assess their photosynthetic response. Rate of photosynthesis, WUE and Ci decreased by 50 %, 53 % and 10 % respectively, and Ci/Ca, E and gs increased by 25 %, 7 % and 3 % respectively when measurements were made at 250 μmol mol-1 as compared to ambient CO2 (350 μmol mol−1) level. Elevated CO2 concentration (750 μmol mol−1) suppressed E and gs ∼ 29% and 42% respectively, and stimulated PN, WUE and Ci by 50 %, 111 % and 115 % respectively as compared to ambient CO2 concentration. The study reveals that this species can be efficiently cultivated in the range of 25 to 30 °C and ∼1500 μmol m−2s−1 PPFD. Furthermore, higher PN, WUE and nearly constant Ci/Ca ratio under elevated CO2 concentrations in C. sativa, reflects its potential for better survival, growth and productivity in drier and CO2 rich environment.
 
diamonddav

diamonddav

Well-Known Member
get the fuck outta here. I just got promoted to a "well- known member" from active member!!! do I get some free seeds or a joint or something!! HAAAAHAAAA
 
Resinhound

Resinhound

Well-Known Member
77-82f keep in mind only cannabis sativa was under testing.But proves nonetheless the link between temperature,c02 uptake and photons,they are all entertwined
 
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