Do I have to rinse the seaweed before adding to compost pile and can I use it as a mulch in the garden without rinsing ?
Seaweed in Compost/Garden
I would not recommend using it without rinsing it off in good clean water. The salts it may have on it could be harmful to the feeder roots on plants. I recommend rinsing it off well then letting it dry out and smashing it up, then add it to the gardens as an additive. Kelp meal (seaweed) has many beneficial nutrients and is a great soils building amendment if used properly. Rosebushes love kelp meal.