The safest method to avoid killing your turf grass is hand pulling Johnsongrass. You can also apply vinegar for a safer herbicide, but it will still burn your lawn if it gets on it.

It usually takes between two weeks and a month for weeds to fully die off after you spray them with herbicide, but they will start to wilt within the first week. Different weed sprays produce different results, with some working more quickly and effectively than others. Similarly, some weeds are killed more easily than others. Consult your weed removal pro for an exact timeline based on their weed removal method.

Yes, organic herbicides and natural prevention methods reduce chemical use.

Due to its slow growth, Bahia grass does not generally take over weeds. In fact, the opposite can be true. Young Bahia grass is susceptible to being taken over by weeds. 

Likewise, in the cool season, Bahia grass goes into a dormant state that can allow weeds that thrive in early spring to get the upper hand. If you want to prevent weeds from taking over your yard, remove them by hand or apply a Bahia grass-friendly pre-emergent herbicide to your lawn before weeds have a chance to appear.