when to flower

[jman23]

im running a 400 watt hps room size is 3x3x6 running 4 plants at what height should i flower to get a 3ft plant plants are about 9" or 10" now

 

[Sunbiz1]

This varies tremendously by strain, but the general rule of thumb is 50% increase in height after flipping. So if the plant is at a 20" height, it should wind up around 30".

 

[jman23]

hmm alright thanks i was told to flower at 12" to achive 3 feet so your saying flower at 20 that seems big

 

[Nice Ol Bud]

Yup pretty much ^^^

 

[jman23]

Yup pretty much ^^^

12 or 20? sorry im confused now

 

[tibberous]

hmm alright thanks i was told to flower at 12" to achive 3 feet so your saying flower at 20 that seems big

Keep in mind that everyone growth rate is going to be different. 2 months in hydro won't be the same as 2 months in soil.

Less important than getting it right this time, is to keep track of how big they were when you went 12/12, so next time you can adjust. You might want to look at topping too if you aren't already - helps the plant fill out the space better.

 

[madmonk]

Bare in mind that a sativa will usually double in height where as an indica will go 50% more.

 

[kryptoniteglo]

Bare in mind that a sativa will usually double in height where as an indica will go 50% more.

Ditto. My sativa-dom 60/40 plants actually tripled. I had to run out and get a tent that's a foot taller just to keep from burning the top colas.

And don't forget to subtract the pot height and light space from the total tent height -- In a 6-foot grow tent subtract 8" for both light and pot (or more for the pot if you're running hydro). That's at least a 16" loss right there. Then you need 14" in general for the space between light and plant (though mine are now 8" below and don't care). So you're losing about 25-30" to the set up.