Acorus

Acorus, often called sweet flag, does not grow from a traditional flower bulb. It is a rhizomatous perennial, meaning it grows from spreading underground stems that form clumps of grass-like foliage. When buying Acorus, you may receive a rooted plant or a piece of rhizome ready to establish. Acorus is mainly grown for its foliage and is especially useful around ponds, in bog gardens and in reliably moist borders.

Acorus grows best in very moist or wet soil, making it a good choice for pond edges, bog gardens and damp areas where many garden plants struggle. Most types prefer sun or light shade. Some Acorus can be planted in shallow water, but the suitable depth depends on the type, so check the product description before planting. As a general guide, keep the crown above the waterline and avoid placing the plant in deep water.

Yes. Acorus is well suited to shallow pond margins and can be grown in an aquatic basket to keep the roots contained. Compact forms can be planted in shallow water, often up to around 10 cm deep, while larger forms may tolerate slightly deeper water. Use aquatic compost or a heavy loam-based soil in the basket, then position it at the correct depth for the plant. Acorus helps soften pond edges with upright, grass-like foliage.

Acorus needs consistently moist conditions. Browning leaf tips or poor growth are often caused by the soil drying out, especially if the plant is grown in a pot or sunny border. Check that it is not drying out between waterings and move it to a wetter position if needed. While Acorus likes moisture, bog-garden types should not be left submerged in deep standing water for long periods. Remove old or damaged foliage to keep the plant tidy and allow fresh growth to come through.

Acorus gradually forms wider clumps through its rhizomes. It is not usually an aggressive plant, but established clumps can become congested after a few years. Divide Acorus in spring by lifting the clump, separating sections with healthy roots and shoots, then replanting them into moist soil or aquatic baskets. Dividing overcrowded plants helps maintain healthy growth and gives you new plants for other damp areas of the garden.