Landman's Dragons misfiring
Two tries from their props were enough for Edinburgh, as WP Nel went over in the first half before Alasdair Dickinson, Tom Brown and Matt Scott finished the scoring for the home side.
The Dragons paid the price for their indiscretions, picking up four yellow cards in the second 40 minutes and Nic Cudd's try was no more than a consolation.
Newport stay ninth in the PRO12 table, and Landman insists things have to improve if his side are going to make inroads into the top six this season.
"There was a lot of ill-discipline from us, and you can't play rugby with 14 or 13 men," he said.
"When you're having to do it for 30 or 40 minutes of the game it really adds up, and we were very inaccurate in our own half.
"So those things together made it tough to play against a quality Edinburgh side, and we'll have to have a good look at ourselves after this.
"But the boys are heading home on Saturday and we'll need to be really positive ahead of the Munster game next week."
