The strands will continue to grow longer and they will also split into more strands. So as it grows it will become thicker. If you have a very small plant that you want to add more strands to, or you want to start a new plant, then you can definitely cut strands off, remove some of the peas, and then plant the stem in dirt. I actually just did that to mine about 2 months ago and let the strands sit in dirt for another month before repotting and giving them as mothers day gifts!