excellent! It is excellent for growing weed under cover. The grass and weeds grow so well that they are more than triple the size of weeds on the lawn. So I have proved that using white tarp is a big mistake to smother weed, however, it might help when it comes to grow veggies.
I have to buy some black plastic sheeting (3mil) from Home Depot and will apply them soon. Hopefully this time the sheeting will kill the weed. Well, as least the chickens love the grass and weeds.