Heading into the pond from the marsh or bog zone, we arrive at the water plant zone. These are the plants most suitable for planting in the deeper parts of the pond and must have their roots under water. In fact they can grow completely under water, to a depth of up to 40 cm. Here again you can use pond baskets for planting. The baskets should be filled with aquatic compost for deep water plants or substrate and covered with gravel.