Sweet Flag Or Acorus Calamus, is, an emergent plant, meaning that it can grow with its roots and part of its leaves submersed in water. Since Sweet Flag can grow to be 4 to 5 feet at full height, it can be planted in up to 6 inches of water or, in a rain garden or boggy area of your garden.

While Acorus Calamus is relatively drought tolerant, the leaves start to shrivel up very quickly when water is lacking. Because it is such an enduring and hard to kill plant, once given water again, its leaves start to grow back quickly.

It is ideal to plant the Sweet Flag plant in the wetland or bog areas of a fish or duck pond because giving them full access to the nutrients of the pond water will ensure faster, more vigorous growth, help balance the pond to keep it from being overrun by algal blooms, and prevent fish kills from too much nutrient buildup in the fish pond.

For ducks, it will provide an evergreen meadow that gives ducks year round protection from flying predators and a nice, high nesting ground for any would-be mama ducks wanting to build nests nearby the water. Since mature Acorus Calamus plants are much larger than the average duck, they can withstand the tender loving attentions of even the most hungry ducks, who may nibble on the tender leaves but tend to leave larger, more mature leaves alone.

If your Sweet Flag plant is a part of an ecosystem pond where the fish or ducks are well-fed, your plants may not need fertilizing at all due to being able to draw nutrients continuously from the pond water itself. Even in ponds where the pond’s inhabitants are lightly fed, Sweet Flag roots can use these nutrients, but there will be less nutrients available, thus slower growth.

If your Acorus Calamus is not being planted directly into pond water where there are wildlife or fish that need healthy water for their life cycles, planting your Acorus Calamus above the water line with a bit of compost and peat moss is an excellent option to get your plant well-started and these planting substrates are excellent at soaking up water from the pond while making those pond nutrients available to the root system of your Sweet Flag.

Another option is to use root tabs, which are popular in the planted tank/aquarium hobby and in the aquascape pond hobby. These root tab fertilizers can be gently nudged in around the root system of the Acorus Calamus to provide a slow-release fertilizer directly to the plant. Root tab fertilizers must be replenished every 3 to 4 months, although winter fertilizing can be skipped since plants tend to go dormant in the colder months.

Acorus Calamus is a rhizomateous plant that can be easily propagated by splitting this large rhizome and planting the pieces elsewhere. I do not recommend cutting the rhizome smaller than about an inch wide, as you will be depending on the energy of this rhizome to grow a whole new plant. Even rhizome pieces that are lacking roots can grow roots when planted somewhere and given plenty of plant nutrition and, if in a pond, secured with a few large rocks to keep it from floating away before it can root down into the soil or pond substrate.