When fixing artificial grass outdoors, it's important to use a weather-resistant adhesive specifically designed for outdoor applications.
Here are two points which needs to be considered when choose the glue:
Weather proof feature. Some synthetic reson glue will goes to powder and crush after some period, under the UV from sunshine.
Anti-water immersion. The artifical grass turf is a kind of fabric or "woven" thing, so it collects rainwater easily. If the glue can not resist the water immersion well, it will go bad and lost adhesion finally.
Based on the two thoughts, DiMei engineers developped EU8260 as a new formula which is specially for outdoor use.
It is a Polyurethane Adhesive: