Follow label directions and heed all precautions. Pesticides are especially dangerous when improperly handled, applied, or disposed. They can injure humans, domestic animals, desirable plants, wildlife and fish, and they can contaminate water supplies. Two general types of herbicides are effective in controlling grasses and broadleaf weeds. Preventing Weed Growth - Prevention is easier than killing grass and weeds after they are growing.
Preventative measures are safer and last longer.
An ounce of prevention is worth a pound of cure. Make sure the ground is well sealed around the seedlings, then spray the pre-emergent herbicides over them. Simazine and Princep are the same product supplied by different manufacturers. Some species are more sensitive to herbicides than others, so always be sure the proper herbicides and rates are used for a particular species. Goal could be substituted for the Simazine in the pre-emergent application.