about pollarding (crop the top) for extra branches

can anyone teach it to me when and how to do it ?

i want to know when i should crop the top of the plant for extra branches?
i need to learn all the tricks about it

i would be appreciated if u can help me
thanks

Well first you want to make sure that the top is big enough to make a clone out of it and than you just cut it off by the two fan leaves closest to the top. You can keep doing that to have a plant get more tops.

do you mean by "two fan leaves", two large leaves or two litlle leaves?

my plants are 20 days old. how much time should i wait for cropping?

After the plant gets 5-8 nodes, pinch the top two or three nodes off and use for a new cutting. Cut the tips off 1/4in. above the last node you want to keep. When the side branches get to this size you can do the same thing again. If you don't want to use the cuttings you can just pinch out one complete node from the tip and the same for the branches that grow from this pinching.

thanks but 1 more thing
i dont want to clone...
i want new branches on my main plant
so i will cut the first node (?) and wait untill new branches appear (?)...
then when the new branches have 3-4 nodes (?) i will do the same (cut off the 1st node on each branches) (?)

This is correct. If you are not going to clone just take the tip out of the plant. When the side branches fill out with four or more nodes do the same thing to the branches formed from the first pinch. Within a week you will see the side branches grow in length as they receive the auxins the original tip was using. You can do this two or three times as the plant grows to make a shorter bushier plant. I stop when the leaves on the stem change from being opposite each other to alternating on the stem.

The nodes are the places where the leaves and new branches arise from the stem. Make your cuts about 1//4 in. above the last node you leave on the plant.

thank you so much.
i will pinch off the very top of the main plant and when the side branches grow and have more than 4 nodes i will do the same again.
and u mean by "1/4" = 4 equal distance between the top and the node closest to the top. (3x) 3 piece of distance will be gone with the top of the plant and there will 1x piece will continue to stay on the branch... like in the picture..i guess

Yes the picture you drew is what I'm talking about. In your diagram you are leaving four nodes with two leaves each and removing the tip of the plant 1/4in above the last node left on the plant. This will cause 8 new branches to be formed in the next week. You will see the new branches forming in the nodes in a few days. You can do this same thing when the new branches grow to the size of the first pinch. If you leave 4 nodes on the secondary branches after pinching, then your plant will grow 8 more branches from this pinch on the secondary limbs. Just pinch and observe the new growth and you will see what I'm trying to explain to you.

When your plant is sufficiently bushy, grow until you have filled 1/3 to 1/2 of your available head space in the grow room, then start the flowering cycle by adjusting the lights to 12/12.

I think this is what you are after bro

https://www.rollitup.org/advanced-marijuana-cultivation/151706-uncle-bens-topping-technique-get.html