When picking plants that go next to ponds, look for ones that can survive in soil that is constantly moist. They should also be relatively resistant to disease and insects. Moist environments are breeding grounds for fungal diseases, and there will be insects of all kinds around a pond. The variety of plants that do well next to ponds includes ornamental grasses and bright flowers. They can be tall and narrow or short and spreading. Getting a good mix will produce a very pleasing pond landscape.
Bog rosemary is not related to the rosemary that is used as an herb. It is a creeping evergreen shrub that will grow to a height of 3 to 4 feet and a width of 3 feet. It is native to the northeastern states, grows rapidly and is resistant to diseases and insects. The plant produces thick, glossy leaves that feel like leather; they are a silver gray color when they are young and become a deep green or a bluish green in color when mature. The pink/white flowers are small, urn shaped and grow in clusters of five or six. When the flowers are done, they leave behind blue seeds that will turn brown as they age. It is hardy in zones 3 to 6, needs full sun or partial shade and does well in very moist soil. The one problem is the fact that the leaves are poisonous to humans.
Variegated Japanese Sedge Grass
Variegated Japanese sedge grass is a plant for the warmer climates, from zones 5 to 9. It grows in clumps that reach a height of 12 to 18 inches and a width of about 12 inches. The plant produces flowers that are brownish green in color and grow in small tufts about the leaves. It needs to be planted in a shady place where the soil is wet and fertile. Variegated Japanese sedge grass is susceptible to infestation by aphids and to fungal leaf spot.
Day lilies are hardy in most of the country, from zones 3 to 9. Day lilies will grow to a height of from 18 inches to 6 feet, depending on whether they are a dwarf or standard variety, They need full sun or light shade and a moist but well-drained soil. The trumpet-shaped flowers can come in any color except for blue, and the leaves are long and resemble grass. Each flower will only last for one day, but each plant will produce many flowers which will open one after the other. Day lily flowers are edible.