The autumn fern provides with its red coloured fronds a beautiful play of colors at partially shady garden places. This is how you plant and care for the fern properly.
Profile of autumn fern:
Scientific name: Dryopteris erythrosora
Plant family: wood fern family (Dryopteridaceae)
Other names: Japanese shield fern
Sowing time: –
Planting time: spring or autumn
Flowering period: –
Location: not direct sun to partially shady
Soil quality: sandy to loamy, lime tolerant, nutrient rich, humus rich
These information are for temperate climate!
Use in: single position, group planting, underplanting, natural garden, park area, rhododendron garden, forest garden
Winter hardiness: hardy, USDA Plant Hardiness Zones: 6 (-20 °C / -5 °F)
Bee and insect friendly: No
Plant characteristics and classification of autumn fern
Plant order, origin and occurrence of autumn fern
The autumn fern (Dryopteris erythrosora) is a fern species from the wood fern family (Dryopteridaceae). It occurs originally in the mountain forests of northeast Asia. It owes its name to the bright red veil of spore clusters on the undersides of its leaves, which resembles of foliage in autumn.
Characteristics of autumn fern
Autumn fern grows to a height of 40 to 80 centimeters (16 to 32 in), is bushy and forms a large and many-headed thicket after years. The fronds do not form a real funnel, but stand close together instead.
The narrow, leathery, wintergreen fronds with triangular outline are reddish to greenish yellow when shooting. In the course of summer they turn a shiny dark green. They are doubly pinnate.
In summer, the spores sit on the undersides of the leaves and are covered by kidney-shaped membranes.
Autumn fern – cultivation and care
The location for the autumn fern should be partially shady. If the stand is humid, sunny places in the garden are also possible. However, the autumn fern should be protected from direct winter sun.
Dryopteris erythrosora requires a deep, humus rich, fresh to moist soil. In addition, the fresh, permeable soil should be low in lime. You can improve some soils that are not optimal by mixing in leaf compost.
You can plant the autumn fern in spring or in autumn, but the best planting time is between March and May. Loosen the soil in the planting hole a little and place the fern so that about half of the tuber is sticking out of the soil. Keep a planting distance of 40 to 50 centimeters (16 to 20 in) and water the plant well.
Prepare the soil well before planting:
- it is advisable to dig up the soil to loosen it
- weeding, removing weeds with the root
- enrich with compost, peat or horn shavings
- put the plant in water so that the rhizome can soak up the water properly
- in the meantime, dig a planting hole twice the size of the rhizome
- keep sufficient distance to other plants
- place the plant as deep as it was before (in the pot), but about half of the tuber is sticking out of the soil
- press the soil and water generously
Since the autumn fern feels most comfortable in a humid environment, both the soil and the air should always be moist. Do something good for the plant, spray the autumn fern with water more often. The soil at the root ball should not dry out, but it should also not cause waterlogging. Use water with as little lime as possible for watering, e.g. rain water. Remember that in a cold location the plant needs less water than in a warm place.
Mineral fertilizer is not suitable for fertilizing. Ripe compost is completely sufficient for the autumn fern. Just leave dead fronds on the ground. The resulting compost will naturally fertilize the soil. The cover of leaves also reduces the evaporation of valuable moisture. Another advantage is that no weeds can grow in these places.
It is not necessary to cut the autumn fern. If you like, you can cut back the plant in spring
- bent or brown fronds can be cut off, but leave them lying around as a fertilizer
- make sure that no newly sprouting fronds are damaged
Older specimens of the autumn fern can be divided in spring or early autumn.
Ferns do not flower, so they cannot form seeds. The autumn fern propagates by its spores. On the underside of the leaves the spores ripen in spore capsules. In late summer, the mature spores fall to the damp ground. About 3 months after falling out, it takes until the first pre-germ buds become visible. It takes over a year for a young plant to grow.
It is easier and faster to propagate the plant by dividing the root:
- the rhizome is dug out in spring and divided with a spade into pieces with at least 1 shoot bud
- Place the root pieces individually in plant containers with growing soil
- keep the earth constantly moist
- the pots spend the winter in a bright and frost-free place
- up to the spring the young plants can grow so far that they can be planted out in the garden
Another easy way is to propagate the fern by means of the breeding tubers:
- The nodules are located on the undersides of the fronds, along the midrib.
- in late summer, when the tubers are ripe, a frond is pressed flat to the ground
- fix the frond with wire clamps at several places so that it sticks to the ground
- after a few weeks the tubers develop roots and the first young shoots become visible
- the young plants are separated from each other and placed individually in pots with a moist, peaty soil
- Bags with air holes put over the pots ensure that the air can accumulate moisture
- the young plants grow into strong ferns, which can be planted out in the garden
It is also possible to divide the frond into individual sections and let the pieces root in seed trays.
Diseases and pests
Snails are not to be feared – the fern expels the snails.
Only vine weevils, very persistent pests, like to gnaw the fern. Signs are holes and bulges on the leaves.
- Lay out bait traps, prepared with nematodes (roundworms).
- The larvae damage the root. This can be prevented by watering the fern with nematode powder dissolved in water.
For winter protection, a leaf or brushwood cover is recommended. Optimal is a light layer of foliage around the plant, as it would be the case in a winter forest. A thin layer is sufficient, a thick layer would start to rot due to the moisture that develops. In addition, early shoots are well protected from late frost by the foliage.
Potted plants can literally die of thirst when the soil in the pot freezes. They must be better protected:
- cover the ground with leaves or brushwood
- wrap the bucket with fleece
- Set bucket higher, e.g. on a block of wood
Use in the garden
The autumn fern shines with its fronds all year round: first in a reddish-yellow tone, later in a rich green. Rhododendron and perennials that prefer shade are suitable companions for the fern, which is wonderfully effective in front of evergreen shrubs or in small groups. Dryopteris erythrosora is also an eye-catcher as a solitaire. The decorative fronds are also used as cut greenery.
The variety ‘Gracilis’ grows to a height of only 40 centimeters (16 in) and, as the name suggests, grows somewhat daintier than the species.