Seachem Flourish Glue for plants:
Overview
Flourish Glue™ is a superior cyanoacrylate gel for attaching moss and plants to rocks, driftwood, and even gravel. It’s uniquely useful when planting bunch plants. Simply apply Flourish Glue™, plant as usual and the plants stay rooted in the substrate. It bonds within seconds and has excellent control, hold and durability characteristics. It can even be used underwater. Flourish Glue™ can be used for any aquascaping in freshwater or saltwater aquariums or for any plastics repairs. Flourish Glue™ comes in an aluminum tube for extended stability beyond products contained in plastic bottles - it won't dry up in the tube.
Directions
Dispense a small amount of glue prior to each use. Apply a small amount of glue to moss or plant roots and press against desired surface for 20 seconds. For bunch plants, apply glue and plant as usual. Wipe tip free of glue before replacing the cap.