Flow Speed: This defined the speed, in cycles per second and direction for gaps, twists, and textures moves, and controls the speed that the tubes grow. You can use negative numbers to inverse the movement.
Textures Flow : This moves the texture down the tubes.
Stroke Time : If you want this option to work, Time Clip must be on. This option will let you animate the tube growth and flow from the beginning of the growth simulation to the end of the growth simulation.
Time Clip : Using Stroke time on, the animated tubes first appear and begin to flow at the time set by Start Time, and die at the time set by End Time.
If Time Clip is on, but Stroke Time isn't, tubes along the stroke path are already planted, which means the tube growth is uniform.
Also define when the tubes appear or born during the grow simulation and when they die. (Start time, end time).
Start Time: this indicates when the tubes appear, but is set in seconds, so if you are working in 24 frames per second and set the start time to 1, the strokes appear in the 24th frame, you can use decimals to set the right number.
End Time : This option defines when the tubes disappear, again is set in seconds, and if you are working with growing simulations try to set this number really high, so you don't get the tubes starting to disappear when your animation is not finished.
Time : Use this option to key frame time. For example, if you are animating the growth of a tree, you can make the tree remain a sapling for the first 100 frames of the animation, then have the tree grow from a sapling to a full grown tree in the next 100 frames.