What is stretch and how can I minimize it?

I think its also good to note the plant is herbaceous! That means it can root from any point on the stem. If your plant stretches after germination, you can add soil to the desired level. Keep an eye on the distance from plant to bulb, adjust bulb height accordingly.
Im sure this was posted a while ago. You can also add dual spectrum lamps. Im using a 600 watt now. Seems okay in veg. Now to see how it does in flower.