Abundantly blooming hydrangeas are a feast for the eyes and enchant gardens and parks with their romantic-looking, colorful flower balls. If the site conditions are right, the shrub is surprisingly easy to care for as a container or outdoor plant. We have summarized the most important care tips for you in compact form.
How much water does the hydrangea need?
The botanical name of the hydrangea is Hydrangea. It comes from the Greek and means "water slurper". It expresses the preference of the pretty flowering shrub for humus-rich and well-damp soils. The hydrangea, on the other hand, does not like drought at all, as it evaporates a lot of water over its large leaf surface.
In dry or sunny weather, the hydrangea therefore needs regular watering. Hydrangeas in pots as well as hydrangeas transplanted outdoors must never dry out, otherwise the plant will wilt. However, you should not overwater the shrub, because the hydrangea is also sensitive to waterlogging.
Always water outdoor hydrangeas fully when the soil feels dry a few centimeters deep. For large tub hydrangeas, we recommend using a moisture meter, which reliably determines the water content in the middle of the pot ball.
How often do you need to fertilize hydrangeas?
Regular fertilization is important so that the hydrangea has enough strength to form numerous flowers. Fertilize during the growth period from May to July. Then refrain from further fertilizer applications so that the shoots of the hydrangea can mature by winter.
Fertilize the hydrangea preferably with special hydrangea fertilizer, as this is nitrogenous and contains little phosphorus. Azalea and rhododendron fertilizers are also well suited.
How do the flowers turn blue?
In order for pink hydrangea flowers to turn blue, the soil pH must be in the acidic range. Aluminum is responsible for the blue colouration, which must be added to the plant in the form of commercially available blue dyes or potassium alum from the pharmacy.
How are hydrangeas pruned?
How often the hydrangea needs to be cut depends on the variety. If you are caring for a hydrangea on the balcony or in the garden, you should therefore keep the plant label well when you buy it.
In the case of farmer's hydrangeas and climbing hydrangeas, it is sufficient to remove the dead or frozen parts of the plant in early spring. Since these hydrangeas already flower in the previous year, the plant will not bloom as lavishly if it is pruned too much.
Panicle hydrangeas, on the other hand, also tolerate heavy pruning well. If you take care of forest hydrangeas or oak-leaved hydrangeas, you can also prune these species more and thereby limit growth.
Remove faded
Don't just cut out the flowers, break them out carefully. This promotes the formation of new buds.
Implement hydrangeas - is that possible?
If you care for a hydrangea, you should leave it in place if possible, because the plant is extremely soil-loyal. If it is unavoidable to move the hydrangea, this must never be done in the summer months when it is in full bloom. The best time for this measure is autumn, when the hydrangea has already faded. Alternatively, you can transplant the hydrangea in the spring before flowering.
Repotting of potted plants
If you are caring for a tub hydrangea, spring is the best time of year to repot the plants. Place the hydrangea in a sufficiently large planter. It should be about a third larger than the previous one. This is not only necessary to give the roots plenty of room to grow. A larger pot also holds significantly more substrate, which serves as a water reservoir. It is recommended to put a drainage layer of expanded clay (€19.73) in the planter. This prevents the substrate from clogging the drain hole and effectively avoids waterlogging.
Is the hydrangea hardy?
Almost all hydrangeas in our gardens are relatively hardy and, with appropriate winter protection, survive cold periods well. Extremely frost-resistant are panicle hydrangeas, which also survive longer periods of cold in rougher areas.
Pot hydrangeas should only be overwintered outdoors in a sufficiently large container and with good winter protection. It is better to keep the beauties in a frost-free room during the cold season.
Is the hydrangea susceptible to diseases or pests?
The hydrangea is quite robust and not very susceptible to diseases and pests. Here is a brief overview of the most common types of damage:
Diseases
Hydrangea virose
This hydrangea disease is very feared because there is no effective remedy to date. The highly contagious plant disease caused by mycoplasma or viruses makes the leaves look dull. The inflorescences and the entire plant remain very small and turn purple to red. Affected plants must be removed and burned or disposed of with household waste.
mildew
This fungal disease can be very stubborn in hydrangeas. You can recognize powdery mildew or downy mildew by the white coating on or under the leaves. Cut off affected parts of the plant immediately to prevent further spread. In addition, the hydrangea should be sprayed with a commercially available fungicide.
leaf spot disease
You can recognize this fungus by the dark colored spots in which an almost black center can be seen. Remove the affected parts of the plant and collect fallen leaves, as the fungus will infect tissue that is still healthy. The trade has suitable sprays ready to combat the disease effectively.
chlorosis
With this leaf disease, which occurs relatively frequently in hydrangeas, the leaf veins turn green, the leaves turn yellow and then fall off. There is often an iron deficiency and the pH value of the substrate has shifted into the basic range. An iron fertilizer and the incorporation of peat or rhododendron soil into the substrate can help.
pests
- Spider mites threaten when the plant is in direct sunlight and suffers from dry soil. The small pests are fought with special sprays that contain rapeseed oil. Sometimes it is enough to shower the hydrangea regularly.
- Aphids can multiply explosively under ideal conditions. In the case of a light infestation, it is sufficient to rinse the pests off the leaves with a sharp jet of water. Alternatively, you can treat the hydrangea with nettle manure or a commercial spray.
- Like many plants with tough foliage, the hydrangea is occasionally plagued by vine weevils. You can avoid spreading by placing jars filled with wood shavings under the shrub, trapping the nocturnal beetles in them and then disposing of them. The larvae of the beetle, which live in the soil, feed on the roots of the hydrangea and can thus cause great damage. They can be successfully combated with nematodes, which are harmless to other living beings.
tips and tricks
The hydrangeas offered as Mother's Day pots in spring are better off indoors or on the balcony than in the garden. If you want to move them outdoors, you should first take care of the plants on the balcony or terrace so that the plants slowly get used to the changed conditions.