<span class="link_user">@purecannabliss</span>
, Thank you for the suggestion buddy! It was because I let them sprout in a dark place. Because of that, they stretched too high. Never happend my before. Defenitly i am changing this method in the future to prevent this issue.
But I buried them deep enough to cover my mistake and it should be no problem, because cannabis can sprout roots anyweare on the stem.