The ranunculus bush, with its yolk-yellow, many flowers in spring, is an extremely cheerful, simple and pretty appearance. He is also extremely undemanding and only needs a little care here and there.
How do I care for a ranunculus bush in the garden?
The ranunculus bush (Kerria japonica) is an attractive, easy-care shrub with bright yellow flowers in spring and early summer. It grows well in sun or partial shade, in slightly acidic to alkaline soil and reaches a height of 1-2 meters and a similar width.
Origin
The botanical name of the ranunculus bush is Kerria japonica - in German also Japanese Kerrie. It is therefore not difficult to guess its area of origin in East Asia. The rose family is monotypic, meaning it has no secondary species within its genus. In Central Europe, the ranunculus bush, which is also called golden rose because of its yolk-yellow, pretty flowers, thrives very well in its native habitat, which is not particularly different in terms of climate. It is frost-resistant and can therefore be planted permanently in the garden without any problems. The shrub is also often used as an ornament in public parks.
Growth
The ranunculus bush shows a very bushy growth with sparse side shoots. As a result, it can quickly appear somewhat unstructured and is not necessarily suitable for dense topiary hedges. Rather, you benefit from its airy, casual branch structure for a cheerful spring garden design if you plant it solitary or in a loose neighborhood with other shrubs. Overall, the golden rose reaches a moderate height of around one to two meters. It forms long root runners and is generally quite easy to care for.
leaves
In addition to the pretty, cheerful flowers, the foliage of the ranunculus bush also has a beautiful decorative value. The light green leaves are alternate on the branches and have an elongated, triangular shape with a long, supple tip. The edge is sharply double-serrated and the pronounced leaf veining gives the leaves a distinctive surface structure. Since the leaves sprout early in the year, the ranunculus bush offers a good opportunity to green up the garden soon after the winter. In summer, when the flowering takes a break, the fresh green foliage plays the main role in the appearance of the ranunculus bush.
Bloom
From its yolk-yellow, open-faced flowers, Kerria japonica gets both its main name, ranunculus (because of its similarity to those of the buttercup), and its nickname, golden rose. They appear in spring and persist until early summer. They are five-fold, plate-shaped flowers with a diameter of around three to 6 centimeters. The flowers of the wild form have many stamens and are simple - some cultivated forms, however, are rosette-like.
Flowering time
The flowers open in April and delight with their golden yellow color and pretty shape until June. In a sense, the ranunculus bush is also a replacement for the yellow-flowering forsythia that came immediately before it. The shrub often blooms again in autumn, especially the Kerria Pleniflora variety.read more
Fruit
In the summer between June and August, small, inconspicuous stone fruits ripen on the Kerrie. They are brown-black in color and have wrinkled skin.
Which location is suitable?
As cheerful and light-hearted as the tendril bush appears, it is also carefree when it comes to its location. It has no special requirements either for the floor or for the light available. It thrives on both slightly acidic and alkaline soils, as long as they are reasonably permeable and fresh. It tolerates a place in the sun as well as a place in the shade of a tree - it perhaps prefers light partial shade. Because in full sun its flowers may fade a little.
The ranunculus bush's resistance to exhaust gases is also interesting for gardens that border busy streets or for planting in commercial areas.read more
What is the best time to plant?
It is best to plant a ranunculus bush in spring. To prevent excessive spread, installing a root barrier is worth considering. You can place the root ball in water before planting for better growth.
The correct planting distance
Keep a distance of about half a meter to a full meter from neighboring trees, depending on whether you are planning a cut hedge or a solitary position.
Watering the ranunculus bush
The ranunculus bush has shallow roots and may therefore need additional watering in longer, hot dry phases. Otherwise, no special watering care is necessary outdoors.
Fertilize ranunculus bush properly
The ranunculus bush doesn't actually need to be fertilized. Let it grow as naturally as possible, because if there is an oversupply of nitrogen, it can be stunted in such a way that it will not produce the beautiful flowers. If you want to do something good for the shrub and make it more resistant to disease, you can give it a little compost in the spring.
Cut the ranunculus bush correctly
Due to its sparse growth, the ranunculus bush can quickly appear a bit unkempt if left uncut. Because of its rod-like branches, you will not be able to keep the shrub compact. Nevertheless, you should regularly limit it a little so that it doesn't become bald from the inside and doesn't suck out the soil too much.
Since topiary pruning is basically pointless, the principle of thinning pruning applies to the ranunculus bush. So remove old branches and unsightly growing shoots regularly, preferably immediately after flowering. Since the Kerrie shows a strong tendency to sprout, you should also keep cutting off excess runners - ideally before they have taken root. The ranunculus bush also tolerates a rejuvenation treatment through radical pruning.
The cutting rules at a glance:
- Regular cutting necessary for an attractive shrub contour
- Topiary pruning not really possible due to very sparse growth
- Instead: thinning directly after flowering
- Radical pruning is well tolerated
read more
Diseases
The Kerrie is not only extremely undemanding in terms of location, but is also very resistant to diseases and pests. However, in warm, humid weather it may become infected with fungi. Powdery mildew and black mold are particularly a risk.
Mildew
With powdery mildew, the leaves are covered by a floury coating that gives it its name. Later they turn brown-black, dry up and fall off.
You can first combat mildew by consistently removing all affected leaves. Do not dispose of them in the compost, but in the residual waste, as the spores can overwinter on organic material. A spray treatment made from diluted milk is also suitable for combating it. If the infestation is advanced and persistent, you can also use a fungicide, preferably based on neem oil.
Star sooty dew
This fungus generally targets rose plants and is shown by black-brown spots on the leaves that spread like rays. The leaves then turn yellow and are dropped. Further consequences include a reduction or even a complete absence of flowering and weakened lignification - this in turn reduces the shrub's frost hardiness, so that it can die in the long term. The star sooty mold should therefore not be underestimated.
Unfortunately, fighting the fungus is not that easy. As with powdery mildew, you should first carefully remove all diseased leaves and dispose of them with household waste. Then apply a spray treatment with a fungicide or with gentler products in the form of horsetail tea or nettle manure.
The fungal spores of star soot are very stubborn and difficult to eradicate completely. To prevent it from spreading, you should cover the ground around the bush with ash or wood chips and always remove fallen leaves thoroughly. In principle, it is also advisable to protect the shrub prophylactically against the infestation by strengthening it with a good supply of nutrients and keeping the leaves as dry as possible. In this way you do not offer the fungus any moist settlement conditions. So only water the root area during dry periods.read more
Brown spots
Brown spots on the leaves and possibly also on the branches are signs of fungal diseases. You can find out more in the Diseases section.read more
Propagate ranunculus bush
foothills
The easiest way to propagate your ranunculus bush is to use its willing and numerous runners. To do this, you simply need to carefully pull a rooted specimen out of the ground and place it back in the desired location.
Cuttings
Another option is the cuttings method. Between June and September you can cut head cuttings about 10 cm long from the upper part of the bush. If you think about it in June, when the annual pruning takes place anyway, you can simply take suitable cuttings from the clippings. They can easily be rooted in a glass of water.
Seeds
The third propagation variant is sowing seeds. However, it is time-consuming and rather laborious and not recommended given the simple alternatives. It is best to plant the seeds in early spring in planting trays with potting soil and keep the substrate evenly moist. Germination can take a few weeks. You can then transplant the young plants and put them outdoors from May onwards, as long as the risk of late frosts is averted.read more
Is ranunculus poisonous?
The ranunculus bush is partially poisonous to humans. Like some other rose plants, its seeds contain the cyanogenic glycoside amygdalin, which is metabolized to produce hydrogen cyanide. This can lead to mild symptoms of poisoning if consumed in excess, but these are usually limited to nausea and vomiting. If small children live in your household or come to visit often, you should be vigilant and, if necessary, prevent fruits with seeds from forming at all by pruning in a timely manner.
The toxicity is not insignificant for cats and dogs, simply because the effective dose is smaller due to the low body mass. In addition, four-legged friends can metabolize hydrogen cyanide more poorly than humans, so increased consumption of ranunculus seeds can cause vomiting as well as more severe energy metabolism disorders such as shortness of breath. See a veterinarian as soon as possible.
To remember:
- Only seeds of the ranunculus bush are indirectly toxic due to the formation of hydrogen cyanide during metabolism
- quite critical for small children
- even more dangerous for cats and dogs
- Prevention: Prevention of seed-bearing fruit formation through timely cutting
read more
Tip
If you want to plant the ranunculus bush as a loose, light flowering hedge, the red dogwood is particularly suitable as a neighboring shrub. Because in the bare winter, the red branches and the green shoots of the ranunculus bush create an attractive color and structural spectacle.
Varieties
Although the ranunculus bush is the only species in the genus Kerria, there are several different cultivars. These are mainly divided into simple and double flowers. Personal taste decides here - the varieties do not differ significantly in terms of location and care requirements.
Varieties with simple flowers
Kerria japonica Simplex:The Kerria japonica Simplex is probably the best-known and most common variety of single-flowering ranunculus bushes. It is also the most similar to the wild form and impresses with its simple beauty with its five-stellate, plate-shaped, golden yellow flowers that appear in April. The Kerria japonica Simplex is one meter high and stretches up to two and a half meters wide. It is well suited for light flowering hedge plantings. It should be photographed regularly.
As planting ground, it prefers a permeable, medium-moist and moderately nutrient-rich soil. The Kerria japonica Simplex is a semi-shade-loving variety and also tolerates full shade. However, full sun can bleach their flowers.
Kerria japonica Golden Guinea:This variety also has simple, but slightly larger flowers than the Simplex variety. They appear in the same golden yellow during a somewhat more limited period from April to May. With their relatively good pollen supply, they are also interesting for insects. The shrub has a somewhat tighter growth: it grows to one and a half to two meters high, but remains comparatively narrow at a maximum of 1.20 meters.
The Kerria japonica Golden Guinea is a little more sun-loving than the Simplex and thrives well in sun or partial shade. She has no special demands on the floor.
Kerria japonica Picta:The variety Picta is a little less well known. Its flowers are quite large and yolk yellow and open between April and the end of May. There is often another bloom in late summer to autumn. You can promote this by pruning after the spring blossoms. The Kerria japonica Picta has a special additional appeal due to its variegated leaves. This means it offers a very decorative look even throughout the flowerless summer.
In terms of growth, the Picta is rather low and wide - it is only just under a meter high and around 1.30 meters wide.
The variety thrives best in well-drained, medium-moist, fresh soil that can be alkaline to slightly acidic. In terms of light, partial shade is best for them.
Varieties with double flowers
Kerria japonica Pleniflora:The name of this variety says it all: its flowers appear particularly rich, not only in number, but also in their fullness. With its lush, bright yellow, feathery, ball-shaped rosettes, it is a particularly attractive flower decoration that you can enjoy in spring between May and June and again in late summer to autumn.
Its high ornamental value makes the Kerria japonica Pleniflora a suitable shrub for a solitary position, but it also looks good in a flower hedge. Although it doesn't branch out much, with regular pruning you can prevent baldness and still achieve quite good opacity. She is also quite vigorous. The pleniflora reaches a height of around one and a half to two meters and a width of up to one meter. The branches hang over slightly in older stages.
As a location, the variety prefers a sunny to partially shaded place and a well-drained soil without a particular pH value tendency.
