The best time to hire a weed service company is in the early spring. This allows them to apply a pre-emergent weed killer that stops weeds from taking root, making maintenance for the rest of the season much easier. Following the initial spring application, a monthly service through the summer and early fall is a good idea for ongoing weed control. These regular treatments, combined with manual removal or spot treatment, should be sufficient to maintain a weed-free yard. Alternatively, you can hire a professional in the fall for the following year, as some companies may offer better rates on contracts signed before the busy spring season.

Glyphosate and other non-selective herbicides can kill orchard grass, but they will also kill the surrounding plants. Also, not all areas allow the use of glyphosate due to its environmental impact—which the EPA describes as a "potential risk to terrestrial and aquatic plants and birds, and low toxicity to honeybees." Consider mechanical removal to target the plants specifically.

The fastest ways to kill weeds and unwanted grass include burning them, pouring boiling water on them, or pulling them out by hand, as these methods work almost instantaneously. For a quick-acting solution that works within a few hours, you can use a commercial-grade herbicide like glyphosate or a DIY vinegar, salt, and dish soap mixture. While effective, be aware that commercial herbicides introduce chemicals into your lawn. The slowest method for killing weeds is to starve them of sunlight and nutrients using mulch or fabric covers.

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.