Osmunda regalis
Royal fern
Common names: Flowering fern
At a glance
- Light
- Partial shade
- Pot size
- from 30 l
- Lifespan
- Perennial
- Hardiness
- Hardy down to −30 °C
- Water need
- High
- Origin
- Native to Germany
Photo: Christian Fischer · CC BY-SA 3.0 · Source
This description was machine-translated.
Description
The royal fern, botanically Osmunda regalis, is one of the largest native ferns. Its bipinnate fronds grow 100 to 150 cm long from a sturdy rhizome that, over the years, forms a trunk-like base. In spring the fronds emerge reddish. In early summer, their tips bear rust-brown, panicle-like spore clusters that resemble flowers, and in autumn the foliage turns yellow to rust-brown. In the wild, the royal fern grows in alder carr woodland, along ditches and in woodland spring bogs. In Germany it is rare and specially protected. Buy plants from a nursery and never dig anything up at a natural site. In gardens, it creates accents at pond edges, along stream banks and in moist beds, and it needs plenty of space.
Care instructions
Plant the royal fern in April in a moist, partly shaded spot, ideally at the edge of a pond or in a depression. It tolerates sun if the soil never dries out, and the cooler and moister the site, the better. Allow plenty of space, as a mature royal fern needs about one square metre. In the first year, water generously and regularly, and later water thoroughly during dry spells. Use rainwater where possible, as it does not like calcareous tap water. The young fronds appear late, from April into May, and late frost can damage them. When frost is likely until mid-May, cover them with fleece. In February or March, cut the brown fronds off close to the ground. Typical mistakes are drought, calcareous irrigation water and too little space. In a container, you need a large pot of at least 30 litres, which you can stand in a tray of water.
The care notes were machine-translated from German.
Soil & site
Soil pH
Soil type
moist, humus-rich, lime-avoiding
The royal fern grows best in permanently moist to wet, humus-rich soil that is acidic to at most neutral and low in lime. It thrives at the edge of a pond, along a stream or in a hollow where water collects. It tolerates waterlogging well as long as the soil stays airy, but hardly tolerates drought. On light, free-draining soils it only succeeds in a large planting pit filled with humus, which you water regularly, or right at the pond edge.
Feeding
Light feeder
The royal fern needs no additional fertiliser. When planting, work plenty of leaf compost into the soil; later, the leaves that lie around the plant in autumn are enough. In a container, replace the top layer of soil every spring and mix in mature compost.
Overwintering
The royal fern is fully hardy and dies back in autumn: from October the fronds turn yellow to rusty brown and die. Leave them standing over winter; they protect the rootstock from frost. In a container, place the pot against a sheltered house wall, wrap it in horticultural fleece or hessian and keep the soil slightly moist. Growth starts in April and May, so be patient even if nothing is visible for a long time.
Propagation
Methods
- Division
- From seed
The easiest way is to buy plants at a nursery, because the royal fern is specially protected and grows slowly. You can divide large, multi-crowned clumps in March or April before growth starts with a sharp spade; replant the pieces immediately and keep them wet. Sowing the spores is demanding: they are green and stay viable only for a short time, so you scatter them fresh onto moist, acidic substrate and cover the container. Collect spores only from plants in your own garden, never at a natural site. It takes several years to reach a presentable plant.
For your garden
Grow Royal fern yourself
Gartenkern tells you when frost is coming, when to sow and when to harvest, for your location.
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