Forsythia: planting cultivation care and flowering

Forsythias are well known for their very early flowering and whose golden yellow color is a real delight that marks the end of winter. These shrubs of the family of Oleaceae are very easy to grow. Some are deciduous, others semi-evergreen. The tallest do not exceed 3 m and there are also upholstered varieties. In our gardens, the Forsythia intermedia (Forsythia x intermedia) nicknamed mimosa from paris is unquestionably the most commonly used in isolation, in beds or in hedges. Let’s see how to maintain it to take advantage of its very generous flowering.

Planter des forsythias

To promote recovery, plant Forsythia preferably early fall, more precisely in September-October, but its planting during the spring, between February and April, remains possible. It is absolutely necessary to avoid periods of frost and intense heat. It is better to postpone its planting for a few days if the weather conditions are not likely to be favorable to it.

The planting of Forsythia in the ground proceeds as follows:

  • Dig a hole approximately 5 times greater than the volume of the root ball.
  • Remove weed roots and stones.
  • Immerse the container in a basin of water to properly hydrate the Forsythia roots.
  • Mix the extracted soil with decomposed manure, potting soil, and if it is particularly heavy, lighten it with a shovelful of river sand.
  • Lay a wire mesh at the bottom of the planting hole.
  • Install the shrub in the center of the hole after possibly scratching the roots too tightly. Make sure the collar is flush with ground level.
  • Plug the hole.
  • Compact the soil sufficiently around the base of the shrub and form a bowl.
  • Water copiously.

If we opt for a Bare Root Forsythia, it is advisable, before planting it, to proceed with pralination. Then, it is necessary to spread the roots of the shrub well at the bottom of the hole, taking care not to hurt them.

Forsythia can also be pot grownin a classic potting soil. It is very important to choose a sufficiently large container and imperatively with a pierced bottom so that rainwater or watering can drain properly.

Growing Forsythias

It’s in very sunny exposure that the flowering of Forsythia is the most resplendent. It is however possible to install it in partial shade. Despite its good tolerance, it has a clear preference for cool, well-drained soils rich in humus. Acid soils, very calcareous and too dry soils are not suitable for it.

Forsythia is used alone or in shrub beds that bloom at different times of the year. It can, for example, be associated with the Mexican orange tree, the Hibiscus or even the Seringat. It also works wonders in a hedge in an urban area where its luminous flowering brings joy as soon as spring arrives.

Caring for the forsythias

Forsythias are sturdy and hardy shrubs, which withstand temperatures down to -20°C. Very easy to maintain, they are suitable for beginner gardeners because they are undemanding.


Of the regular watering are needed during two years after planting Forsythia, especially in summer and in the event of severe drought, about once a week. With regard to subjects grown in pots, water when the substrate begins to dry out. Care must be taken not to allow water to stagnate in the saucers. Of course, in the ground as well as in pots, watering must be reduced from autumn to spring.


And organic mulch is useful since it allows the soil to stay fresh longer and limits the development of unwanted weeds.


A training size from the first year following their flowering is strongly recommended because it allows you to keep only 4 or 5 perfectly oriented carpenter branches. In this way, the shrubs will have a beautiful architecture.

Subsequently, in May-June, that is to say after flowering, the size of the Forsythia is essential. This consists of cutting short so that new twigs form and have enough time to become strong before winter.

We perform a discount days in the subjects who pushed in an anarchic way and were undoubtedly not guided. The young subjects are folded down to 30 or 40 cm from the ground. For forsythias aged 5 years and over, the length of the oldest branches should be reduced by around 50% and the heart of their branches should be well ventilated.

Note that the forsythias used in hedges require a annual pruning supplemented by a small thinning with secateurs as needed to keep the hedge looking neat.


You don’t have to do not overuse fertilizers because it promotes phytophtora, a disease that can be fatal to Forsythia. An amendment in the fall is welcome. We are then content to deposit a small layer of compost at the foot of the forsythias.

In the spring, all you have to do is add a dose of soluble organic fertilizer for cultivated shrubs to a watering can. in tray to support the growth of young forsythias.

Pests and diseases

The scale insects can colonize Forsythia and cause its decline. Sprays of black soap should be carried out as soon as these parasites appear. In the event of a major attack, the shrub is treated three times a week with an insecticidal oil spray. We should also know that in very hot and dry weather, the red spiders can attack Forsythia. The shrub must be misted with cool water in the evening to see these undesirables disappear or spray the foliage with soapy water.

Forsythia can also be affected by various maladies cryptogamiques greatly favored by excess humidity. When the damage is done, to avoid rotting, it is necessary to resort to an antifungal. However, if the subject is too affected, we have no choice but to delete all the parts concerned and burn them. In extreme cases, the shrub must be cut down. Among the fungal diseases that are difficult to eradicate, ink disease or phytophthora which can be due to an excess of fertilization, imposes the uprooting of the sick subjects in order to avoid the contamination of the other trees and shrubs.

The galle Forsythia is also a fungal disease, fortunately harmless to the shrub, but which causes unsightly blisters and can still weaken the subject. The diseased parts must be removed and then treated with Bordeaux mixture by repeated spraying at the beginning of winter and spring, including on nearby trees in order to limit the risk of contamination.

Flowering of forsythia

The more it is exposed to the sun, the more the Forsythia blooms. It is therefore at the planting that we must find the best location for it so as not to have to move it later. Its flowers possessing male and female organs, they are said to be hermaphrodites. They are simple, made up of four petals forming a bell in the center of which are the stamens. Their golden yellow color is flamboyant and attracts all eyes.

We can create sumptuous bouquets of cut flowers with Forsythia twigs in buds. The base of the stem must be crushed with pliers so that it can absorb as much water as possible, much more in any case than if it had been cut clean. pick some Forsythia button twigs is an excellent solution to bring a breath of spring inside the house. It is necessary to change the water regularly to see the flamboyant yellow flowers blossom little by little and illuminate its decoration, and a few pieces of charcoal deposited at the bottom of the vase will prevent the water from stagnating.

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