Encyclopedia - Plants for ponds
Calla (Bog arum)
Calla palustris
Calla, or calla (lat. Cálla) — a genus of perennial shade-tolerant marsh or shoreline herbaceous plants of the Arum family, or arums (Araceae). The genus is the only representative of the subfamily Calloideae and includes only one species — the bog calla (Calla palustris L.).
Range — from temperate to tropical regions across the entire Northern Hemisphere. It occurs in many regions of Ukraine and Russia, from Europe to Siberia and the Far East.
Calla is a bog plant; it inhabits marshy shores of ponds and rivers, and wet, swampy places. It is grown as an ornamental plant and used in landscape design.
This is a perennial herbaceous plant with creeping or prostrate shoots 10—25 cm high. The rhizome is green, jointed, creeping, hollow and thick; it spreads along the soil surface. It branches; adventitious fibrous roots arise from its nodes.
Leaves are solitary, on long petioles, alternate, ovate-cordate, with pointed tips and a smooth margin. The blade is thick, glossy, 6—14 cm long, 5—11 cm wide, with pinnate-arching venation, ovate-cordate, acutely drawn out at the apex; dark green above and paler beneath. The petiole, up to 1 cm thick, arises above the base of the membranous sheath, the upper part of which projects freely, forming a large tongue. On dried specimens the petiole often becomes yellow or orange.
Flowers are unisexual, small, up to 1 cm, without a perianth, gathered into dense spadix inflorescences on a thick vertical stalk, surrounded by a spathe leaf that is green outside and white inside. The spathe becomes green after the flowers are pollinated and serves for additional photosynthesis. The height of the inflorescence equals the length of the leaf. Flowering time — from May to July.
Fruits are small (6—8 mm in diameter) bright red juicy berries, ripening one month after flowering, forming a cylindrical spadix. Fruiting occurs at the end of August.
Location: if planted in a sunny spot in still water, its glossy heart-shaped leaves up to 20 cm wide will completely cover the edges of a pond, so it is recommended to plant it in garden ponds with a hard lining. It tolerates temporary drying out of the water body.
Soil: requires silty or clayey, nutrient-rich soil.
Planting: plant at a depth of 5–10 cm. To avoid water "blooming" it can be planted not in mesh containers but in ordinary pots or containers with holes only in the bottom. Such a container is filled with soil, which is covered on top with a 2-centimeter layer of heavy clay to prevent nutrients from being washed into the water. The plants will spread, and part of them will hang over the edge of the container, where newly formed roots will take up nutrients from the water, improving its quality.
Care: the plant forms a dense carpet that suppresses everything around it. It grows quickly but is easy to control. Shoots that extend beyond the border should be pruned.
Propagation: by sowing seeds in autumn or by dividing rhizomes in spring.