How much cold can a plant stand?

Hi, I couldn't find my old topic so I guess I'll start a new one ...
I have a four plant outdoor grow and I'm waiting for the plants to start flowering. Now where I live, the 12/12 light conditions start at about mid-september. And that kind of worries, me since the night temperatures around here have begun falling like a rock. It's been only 7*C last night and it's supposed to be even colder today ... Should I be moving them inside? I don't really have a growbox or anything, figure a windowsill will do?

Thanks!

Ok, like all of the Northern Hemisphere is moving to 12/12 about mid September

Based on your temps, I doubt you will see much before the plant dies outside.

Can you keep the room with the window completely dark for 12 hours? Might work, but a window is only going to let in so much light. You might be able to supplement with CFL.

Could you make a cheap grow tent with CFL's and panda film?

Look I know next to nothing, but these are my thoughts.

You still want to get at least 4 hours of direct sunlight to get some buds of the plant so try to choose a window that will shine all day. I grow my plants were the lowest temps are down to 50F but my day time temps come up to 70F. The only thing that would probly happen is your plants will turn purple due to the cold. I have heard people leaving them out side just above freezing and they would snap out of it but if you can move in side.

if water freezes your plant is dead

So, they should be fine outside for now?

Just in case I went round the house and found a pair of bulbs, I think they're CFL ...


It says here on the bulb ...
50/60Hz | 80mA | 11W (~ 60W) Warm White 2700*K
... The big one is 15W (~ 75W).
I'm guessing this won't be enough by a longshot, eh?

Imladris said:

So, they should be fine outside for now?

Just in case I went round the house and found a pair of bulbs, I think they're CFL ...


It says here on the bulb ...
50/60Hz | 80mA | 11W (~ 60W) Warm White 2700*K
... The big one is 15W (~ 75W).
I'm guessing this won't be enough by a longshot, eh?

Click to expand...

for cfl's, the formula i've seen is 100w for the 1st sq foot, 50w for each additional sq foot
so you will probably need more, unless your plant is very small

with 26 watts you can grow 1 plant that will yield from 5-10 grams

Allright, so for 4 square feet I'd need about a 100W in the center and a 25W in each corner. That would work, right?
What kind of bulbs would one use? ... In fact, what kinds of light bulbs are there? I know CFLs, as far as I know those are energy saver bulbs. Now I heard about HSI, HPF, MH, warm and cool ones, etc ... What's the deal with that?

lot of bulbs, lot of choices
cfl's are good for simplicity and easy setup, 26w(actual watts) have the best lumens per watt output, these are also quite inexpensive
HPS(high pressure sodium) is the choice of many inside growers, very high output in the red spectrum, but getting one setup can be a bit more intense for a beginner doing an inside grow
MH(metal halide) are a bluer spectrum, inside growers tend to use them for vegetative growth, but they can be used for flower, like HPS, setup can be more complicated