For sure. Just close the trench or opening all the way. Which is a must no matter what. But - the only risk with simazine is it flowing into the root system. Non issue if close row or hole.
U probably wanna watch for grasses…. Metolachlor or imazapic (plateau) good options Can do it later too or spot spray with clethodim & crop oil. Usually, I do second spray as needed with cleth & crop oil + a few other pre’s such as simazine, plateau, metolachlor, Surflan, etc.
Judging from the trees in the field edges along the fields I spray they can take a lot of abuse from a wide variety of chemicals and seem to grow back faster. I had a patch of cedars I planted for a screen that got overtaken by poison hemlock about ten years ago. I hung the boom over them with roundup and harness extra and drenched everything. The cedars were the only thing left alive and they are twice the size of the ones I didn’t hit.