urgent need of assistance (plants growing to big i think)

Topping is best applied in the vegging phase of growth, which allows the plant to grow many mature branches capable of holding flowers. I'd say 2 weeks before the switch to 12/12 is the cut off for topping. Of course, different strains and growers may have varying results.

What's your light source? There IS a common phenomena known as "the stretch" that occurs during flower, but 11" in 5 days seems alot. If they're not getting the PAR (Photosynthetically Active Radiation) they want, they'll stretch for it. The distance from canopy to bulb determines the achievable PAR. Bigger bulb, higher wattage, more lumens, more potential PAR.

You CAN LST or otherwise train the plant to conform to your space at any time. Try looking into LST and/or training your plants.

 

If you top them you should stop all upward growth which would promote more branching. Marijuana is known for its booming rate of growth, and in the cannabis grow bible (which is a great reference for all types of growers) and from personal experience, they can grow upward of 3" in a 24 hour period. Try training some branches, or even topping branches that are growing too tall, which will create more sub branching. Don't worry though, as long as you keep a 14" radius and a fan to blow between the canopy and lamp to reduce heat, you should be fine. If you notice some leaves burning or crisping, or leaves begin to curl upwards due to heat exhaustion, you will be just fine.

Work on your bonsai skills with this one, do some good tie downs and readjusting. Will help you with future grows

 

Stake em down

 

I had the same prob Fogman. What really worked for me was Super Cropping. Its really scary to do cuz u think your hurting the plant but it works pretty well. All you got to do is pinch the main stem of the plant and roll your fingers so you crush the Kurd inside the plant.

This will cause the plant to be weak in that spot and hunch over like an old person. For like 3 days only its branches will grow then the top will start growing up again, but by then you can start tieing it down to keep it horizantal.

Check out my plants if you need to see what i mean.

 

Best idea i've heard yet. A practice so second-nature to me, i didn't even think to mention it. LOL Fu@kin' stoner

BTW: OP You can technically still top/prune if you have to. But i would save this for a last resort. Topping after switching to flower will promote flowering on branches that have not had the opportunity to develop. This will tend to lead to the formation of smaller buds that grow all bunched up. I know this. I've done it. Not looking to repeat. 'Nuff said on that.

You can take your advice from someone with a utility-belt packed with links & books, or from someone who doesn't need either

 

I hope for your sake they do stop stretching. It really depends on alot of factors. Unfortunately, for you, i sense that the stretch will last for the 1st ~2weeks of flower. As is typical. Better have those clippers ready LOL

Supercropping is not scary at all. You squeeze the stem, rotate your pinching fingers 90º and pinch again. (Only hard enough to collapse the stem, not snap it in two). Then let the stem lean over (hinging on the break) a bit. If you allow the branch to lean over so far it is hanging upside down, you've gone too far. The idea is to create a wound in the stem that the plant WILL try to heal (and most of the time it will) by pumping all sorts of hormones and stuff to the site of the wound.

You want the plant to still be able to transport chlorophyl through the stem, so propping it, or tying it, or somehow remanding it stationary will aid in this process. This will trick the plant into allocating hormones that are otherwise destined for the main/terminal cola.