Soil

Like pots, there are many types of soil. Soil has two main purposes; anchoring the plant and holding nutrient. How each soil performs these 2 functions is the biggest determinant is selecting your soil, although cost and availability are certainly factors as well.

Clay Soil. Clay soil is one of the best options for aquatic plants. It holds nutrients and anchors all plants very well. However, too heavy of a clay concentration in the soil can reduce healthy root growth. If available, this garden soil could be dug up from your yard or occasionally purchased.

Sand. Sand can anchor shorter plants well, but not tall plants. It will hold some nutrient but not as well as a clay-based garden soil.

Gravel. Gravel can be used for short plants, but is very poor at nutrient retention. Gravel can work when the plants are for filtration purposes, but any fertilization, will just be released into the water.

Aquatic soil is usually made up of kiln-fired clay particles. It is a great choice for aquatic plants as it holds nutrients well and provides a strong base for anchoring plants.

Potting Soil. Bagged potting soil is not an acceptable soil for the water garden. It is too light and usually contains too many organics.

Fiber. Fiber rolls and block such as rockwool or coconut fiber can be used for some plantings. However, they are very poor for nutrient retention and also will only anchor short plants.