The purple red flowers and finely slit foliage make the fernleaf peony a special perennial. This is how planting and care are successful.
Profile of fernleaf peony:
Scientific name: Paeonia tenuifolia
Plant family: peony family (Paeoniaceae
Other names: thin-leaved peony, narrow-leaved peony, steppe peony, fern leaf peony
Planting time: autumn
Flowering period: May to June
Soil quality: sandy to loamy, nutrient rich, humus rich
These information are for temperate climate!
Use in: flowerbeds, borders, flower garden, natural garden, rock garden
Winter hardiness: hardy, USDA Plant Hardiness Zones: 6 (-20 °C / -5 °F)
Bee and insect friendly: Yes
Plant characteristics and classification of fernleaf peony
Plant order, origin and occurrence of fernleaf peony
The fernleaf peony (Paeonia tenuifolia) is a noble and not quite cheap treasure from the peony family (Paeoniaceae), which is usually only found in perennial and special nurseries. The special thing about this species is the very finely slit foliage, which reminds one of Japanese maple or even of dill and fennel and makes it a filigree appearance. Accordingly, its species name “tenuifolia” means fine, thin or narrow-leaved. Under the tender exterior, however, an extremely robust nature is hidden. At its nature-sites in the Caucasus, in Asia Minor and on the Balkans, the fernleaf peony, that in some areas also as “thin-leaved peony” or “narrow-leaved peony” is called, grows above all on dry-meadows. It was first mentioned in writing by the botanist Johann Georg Gmelin (1709-1755), who discovered it on an expedition in the middle of the 18th century. The peonies are slightly poisonous.
Characteristics of fernleaf peony
Paeonia tenuifolia belongs like the common peony (Paeonia officinalis) and the Chinese peony (Paeonia lactiflora) to the perennial peonies. Every spring, their initially orange-red shoots push themselves 50 to 60 centimeters (20 to 24 in) out of the ground. The absolutely frost-hardy plants grow in clusters that only grow slowly – but grow many decades old.
The finely slit foliage of the fernleaf peony is a great eye-catcher even without flowers. It is deciduous and pulls in soon after flowering.
In May and June, with the warm spring weather of the past years often already in April, the wild species Paeonia tenuifolia opens simple brick red flower bowls. In its center sit the clearly visible yellow stamens, which attract plenty of bees.
After withering, two or three felted follicle fruits develop from the flowers – if the perennials are left standing.
Fernleaf peony – cultivation and care
Fernleaf peonies desire a sunny, warm place in the garden. Even heat does not bother the plants.
Unlike its relative peonies, which love clayey soils, Paeonia tenuifolia needs a light, permeable and rather dry soil. It should nevertheless be rich in nutrients. It is best to excavate the planting area generously and improve the excavation with sand and/or chippings and compost or organic fertilizer so that it is deep, loose and yet humus. Coarse gravel is less suitable for the fleshy roots.
Planting fernleaf peony
When planting fernleaf peony, the same applies as for other perennial peonies: the rootstock must not be more than 3 centimeters deep under the surface of the soil. If the flower fails sparsely or completely, it could be because the clusters are too deep. The best planting time for peonies, especially rootstocks, is autumn. Container goods can theoretically be used all year round as long as it is not too hot and dry or the soil is not frozen. In the first winter a covering of spruce brushwood is advisable, after that it is no longer necessary and the plants are completely hardy. Due to their slow growth, you can plant them a little denser, but not more than two, at most three per square meter (10 sq ft.).
Short-term drought cannot damage the plant. The situation is different with waterlogging. This favors the infestation of tubular fungi. These pathogens cause the root rot feared by gardeners. In advanced stages, this results inevitably in the death of the affected plants.
As with almost all perennials, the root ball of the narrow-leaved peony should not dry out completely. On hot days it is useful to check the moisture content of the substrate.
- water in the morning and late afternoon
- use lime-free water
- regularly supply young and flowering plants with water
Watering during midday, when the sun burns directly on the leaves and shoots, stresses the plant. There is a high risk that much of the valuable water evaporates too quickly. Bark mulch is a good material to bind the moisture in the soil. It fulfils various tasks and, among other things, ensures that the evaporation rate remains low.
The fernleaf peony is frugal. This is also reflected in its nutrient consumption. If the beds are mulched in spring and compost or horn shavings are applied, the peony has nothing against a good portion of fertilizer. At the latest every two years, nutrients must be added to the substrate, otherwise the growth of the plant will stagnate. If you want to use products from the trade, you should buy a conventional slow release fertilizer. This is used shortly before flowering.
The above-ground shoots wilt shortly after flowering. In late autumn, the withered shoots are cut to about 10 centimeters (4 in) above the ground. This prevents fungal infestation in the following year.
Further helpful tips to promote the growth of the peony:
- remove withered flowers immediately
- cut frozen shoots in spring
- the stem of the peony must not be squeezed
In order not to promote diseases unnecessarily, the incision is made on a dry, sunny day. Preferably in the early morning.
What many hobby gardeners do not know: The fernleaf peony makes a distinctive vase decoration. The flowering shoots are cut and the lower leaves on the stems should be removed immediately.
- shorten the stem every 2 days
- change the water regularly
- Vase should be placed in a bright place without drafts
The fernleaf peony hardly need any care if they are in the right place. Their shoots are usually stable, they tolerate dryness and heat. In spring, when they are ready to sprout, they are grateful for a dose of compost and horn shavings, which are added gently. Take care not to over-fertilise them with nitrogen, as the shoots will then become soft and bend over or even rot. You can cut off the early drying stems if you find them visually disturbing.
Apart from patience, a lot of tact and sensitivity is needed to ensure that the propagation works. The shrubby plant can be propagated in three ways: by grafting, sowing and by root division.
In grafting, a shoot is grafted onto the roots of another shrub peony using a special cutting technique. This method is not easy for beginners, but it has one decisive advantage over the cultivation by seeds: these plants develop their flowers after only 2 or 3 years.
Propagation by sowing
The fine leafy fernleaf peony should be sown outdoors. It is almost impossible to stimulate the plant to germinate in a container. Another point: It may take 16 – 20 months until the first shoots appear. The seeds have to go through different cold and warm periods. These requirements can be met better outdoors than on the windowsill.
The following tips can be used to prepare for growing seeds:
- Clear the bed of weeds, roots and stones in late summer
- sowing the seeds
- press lightly
- Cover only minimally with substrate
- carefully water the floor
The sowing area should remain weed-free. This is a challenge because not every plant is immediately recognized as an undesirable plant. The longer the roots of the plants become, the more likely they are to displace the seeds and prevent germination. Fernleaf peonies, which are propagated by seeds, only flower after about 6 years. Patience is therefore required in many aspects of this propagation method.
Propagation by root division
Older fernleaf peonies can be propagated by root division. This method is demanding, considering the impressive length of the tap roots. The plant is dug up in spring or late summer.
- divide the rootstock with a sharp spade or an axe into equally large pieces
- plant the peony parts in the garden as usual
- water vigorously and keep sufficiently moist for approx. 14 days
Further steps are not necessary. As with the previous propagation methods, the split fernleaf peonies need a few years before they reliably show their lush flowering.
Diseases and pests
The fernleaf peony is relatively resistant. Cell sap sucking insects avoid the plant. There is a disease, but peonies can be affected by it: The grey mold. These fungal spores are favored by a humid and warm spring. With shrub peonies the complete shoots wither, with perennial peonies only isolated buds and stems.
Paeonia tenuifolia belongs to the shrubs, in case of an infestation the affected plant piece is removed down to the healthy wood. With special fungicides from the specialized trade one can fight the fungus pathogen effectively.
Paeonia tenuifolia is robust, which is especially evident in the cold season. Due to its long taproots, ice and snow cannot harm the fernleaf peony. The plant survives temperatures down to -20 °C / -5 °F without damage. The young shoots react more sensitively to late spring frost.
If you have seen the weather forecast in time, you can cover the perennial with a fleece. The bushy plant has no objections to the application of bark mulch in autumn. The material warms and releases nutrients to the soil. Fertilization and watering is not done in winter.
Potted plants run the risk of the soil in the container freezing completely. This can inevitably lead to the death of the fine-leaved peony. As a preventive measure, the pot is wrapped with bubble wrap or sacking. Further precautions are not necessary.
Use in the garden
Paeonia tenuifolia is ideal for sunny open spaces, gravel beds and rock gardens. Pretty, simultaneously flowering partners are allium, spurge (Euphorbia), foxtail lily (Eremurus robustis) or pasque flower (Pulsatilla vulgaris). As the foliage becomes unattractive quite soon after flowering, it is advisable to combine some species whose leaves cover the gaps that appear. For example, purple cranesbill (Geranium x magnificum), lady’s mantle (Alchemilla epipsila), large-flowered and veined catnip (Nepeta grandiflora and Nepeta nervosa) or Turkish sage (Phlomis russeliana) are suitable.
In addition to the wild species, perennial nurseries often offer the variety ‘Plena’ or ‘Rubra Plena’. It grows more compact, reaches a height of only about 40 centimeters (16 in), flowers dark red and has a double flower. The pale pink ‘Rosea’ selection is much rarer – perhaps because it is considered somewhat sensitive. Occasionally the ‘Rosea Plena’ variety with double pink flowers is also offered. A rarity is the coarse-slit peony (Paeonia tenuifolia biebersteiniana). It grows to a height of 35 to 40 centimeters (14 to 16 in) and flowers with simple, purple-red petals.