Now I don't fully understand which location on the plant you chose to tie your plants off at, and I don't know if you have done this to allow side growth or if you have done this due to its weight increasing and not being able to stand by itself. there is a "BUT" here. Regardless your going to want to keep it tied down until harvest day.
TIP:If your using it to hold your heavy colas upright, then you can use a tomato cage which has 360 degrees of coverage to hold those ladies up. also you can try bamboo because it may be a bit cheaper. place the bamboos in 3s around your plants creating a triangle shape then try placing tomato clips around the lower stems. you shouldn't have a problem holding them up if you use the clips and make sure you "lollipop" which is essentially taking off all the sucker leaves at the bottom of the plants before and during the first week of harvest. Remember you want to take off about 1/3 to 1/4 off your plant depending on its growth style and her genetics.