Well depending on the strain you can top quite a bit but there are drawbacks.....everytime you do it you are stressing your plant of course which I have not really had a problem with but maybe others have. The other is that the more you top the more time you have to give the plant to grow new foliage in which extends your vegging time depending upon how many times you do it. The plant in pic 2 ended up with four main colas and don't know how many side ones...I top everything on the plant I can; not just the main stem. Make sure you have a strain that responds well to topping or it could result in a much poorer yield all around.