Exploding Rosemary Plant 🦚😳

My gardening style is very feast or famine; I either kill the plant, or it explodes and overtakes everything in its presence. This rosemary plant has been stagnant for years. I even had to add plants to the right and the left because the planter looked so empty. Now, since adding a shade sail overhead, the rosemary plant has sneakily exploded. Apparently, the metal planter and the afternoon sun were a bad combination. I didn't really notice how rapidly the plant was growing until it was close to overtaking the plant on the right. I had to move that plant to a new location quickly. This year, I'm desperately trying to keep the rosemary plant from overtaking the plant on the left while I get a space ready in the front yard. Fingers crossed!