Pond grass can ruin the attractiveness of a pond, lead to a buildup of sludge, and prevent fish and insects from surviving within the pond. Removing pond grass from a pond can be challenging because many of the grass removal methods can ruin the life forms in the pond. Also, pond grass will often come back unless the pond is permanently made as inhospitable to pond grass as possible.
Create a weed killer made out of salt and vinegar. This weed killer will not kill the fish swimming in the pond.
Pour boiling water on the grass. This might take several applications, but the boiling water will not hurt anything in the pond.
Spray Roundup Weed & Grass Killer on the grass.
Pull stubborn grass out of the ground with your bare hands. Make sure that the root of the grass is pulled out along with the blade of grass. If the grass is numerous, rake it out frequently until there isn't so much grass.
Add dark, non-toxic dye to the water. This dye will prevent grass within the water from receiving sunlight, which will in turn prevent the grass from receiving the sunlight it needs.
Increase the depth of your pond. Pond grass cannot grow in very deep water. The depth of the pond can be increased by draining the pond and then using a shovel to dig mud and dirt out where the pond is the most shallow.
Find fish-friendly herbicides that will kill the pond grass.
Add grass-eating carp to your pond.
Remove all grass from ponds that are filled with pond grass. Shallow ponds with large amounts of grass will have sludge. This sludge is great compost material.
Remove the rest of the sludge with a whisk broom, since anaerobic bacteria will have released hydrogen sulfide, which will kill fish and insects. Also, ammonia released will increase the amount of algae in the pond.
Return everything you want in your pond to the pond after cleaning out the sludge. Use a garden hose to fill the pond up with water.