New Grower Tap Roots growing out of top of rockwool?

[medicineforme]

I recently cracked 7 dp td's and a couple other photos and each one I put into a round rockwool cube after the beans cracked and the root was visible. I put them in the slit of the plug so that the tap root would point down. But on just about each one the damn roots were coming out of the top right beside the seedling.

I just carefully took the top of the plant and rotated 180 degrees in the slit of the cube and now the root is pointing down and plant up. But anyone know why this happens? Especially on nearly all I planted?

 

[Wombat Jenkins]

Same thing happened on all of mine, the root broke the surface of the cube, then headed straight downward once it hit the light and proceeded out the bottom.

 

[medicineforme]

I just flipped the stem of the plant in the cube to help it along. Very strange though, I agree.

 

[1highman]

Same thing happened to 1 of mine, and as I was flipping her back the right way, the tap root broke. I call her "The Runt" and she has survived so far.

 

[LittleBadger]

same thing happened to 3 TDs i planted last week