Hydrangea care: expert tips for growing hydrangeas
This article will provide you with everything you need to know about hydrangea care: from planting and growing to cutting and choosing the right variety.
The Hydrangea genus consists of 70 different species, most of which originate from East Asian regions. All species are woody plants that can grow in different ways – either as small shrubs or as climbing plants that conquer astonishing heights. In this article, you can learn everything about hydrangeas.
The flowers of the hydrangea are usually arranged in panicles or umbel-like inflorescences. The larger, more visible flowers, which make up the actual ornamental value, are merely so-called mock flowers. The real flowers, which contribute to the seed development, are hidden inside the inflorescences and are not visible at first glance. In the following we would like to take a closer look at the hydrangea, the various varieties and their care.
Hydrangea species and their varieties
All of the most notable species are deciduous shrubs, which means that they are leafy in summer and cast off their foliage in winter. The biggest star among hydrangeas is the Hydrangea macrophylla which originates from Japan and is also referred to as bigleaf hydrangea. Its characteristic inflorescences are either spherical or flat like a plate and less strongly peppered with the large ornamental flowers. In addition to the bigleaf hydrangea, the panicled hydrangea (Hydrangea paniculata) and the smooth hydrangea (Hydrangea arborescens) are also very popular. For those who want to embellish their gardens with not just stunning flowers but also decorative foliage, the oakleaf hydrangea (Hydrangea quercifolia) is exactly the right choice. Besides the Hydrangea sargentiana, which is known for its velvet soft leaves, there are also climbing hydrangeas (Hydrangea petiolaris) and the tea of heaven hydrangea (Hydrangea serrata).
This article is an overview of different hydrangea varieties of the above-mentioned species.
In the following you will learn which location and which soil conditions that hydrangeas require. The differences in care depending on planting hydrangeas in pots or beds are also discussed.
Planting hydrangeas in garden beds
As far as the soil is concerned, hydrangeas have specific requirements. If the pH value is between 4 and 5, it is optimal. If the hydrangeas are to shine in strong blue or purple, the pH value of the soil may generally be somewhat lower than for pink, red or white hydrangeas. If the pH value is slightly more alkaline, it does not have any life-threatening effects on the growth of the hydrangea. However, alkaline soil can in the long turn lead to deficiency symptoms and the desired colour may not develop. In addition to the correct pH value, hydrangeas also need a sufficient water supply, otherwise dry damage can quickly occur. It is therefore advantageous to select a location where the soil has good water storing capacity. However, the subsoil must not be prone to waterlogging as this could quickly lead to root rot and the subsequent death of the plant. Once a suitable location has been found, the next steps should be considered. For soils with too high a pH value, it may be a good idea to dig a slightly larger hole. In this way, there is room for some extra substrate with a suitable pH value, such as rhododendron substrate. The hydrangea should be well watered before and after planting. The soil is then loosened a bit around the plant to make it easier for the hydrangea to take root. Keep in mind, that under no circumstances should the loosened soil around the hydrangea be compacted to “hold the plant” in place. That is a common misconception and does not do the plant any favours.
Planting hydrangeas in pots
With regard to the location requirements, it makes no difference whether the hydrangea is planted in a pot or in a garden bed. The hydrangea can be perfectly happy even in a flower pot especially if it is in a semi-shady area. However, the hydrangea has to be watered more often in a pot than in a bed. Therefore, choose a sufficiently large pot. It is also recommended to use rhododendron soil to plant hydrangeas in. For an optimal water supply right from the beginning, the hydrangea can be dipped into a bucket filled with water before planting. The plant is kept completely under water until no more air bubbles rise. After planting, you should water the hydrangea thoroughly again so that the loosened substrate settles and the roots have access to water and nutrients.
Hydrangeas on the balcony
If you have planted your hydrangea in a pot, you can also keep the decorative plant on the balcony. Since hydrangeas prefer shady locations, an east, west or north facing balcony is perfect. If you want to keep your hydrangea on a south-facing balcony, shade it in the midday sun and make sure it has enough water.
Hydrangeas are reliable flowering classics in the garden – but only with the right care. From watering to fertilising to cutting, in this segment, you can learn everything about the correct care of these stunning plants. To find out further details on hydrangea care, you can read this article.
Hydrangeas are thirsty plants and must be watered regularly. Particularly during hot summers, hydrangeas have to be watered up to several times a day. Hydrangeas planted in the bed can also suffer from a lack of water and should be watered regularly to avoid unnecessary drought damage such as dried leaves and flowers.
Every type of hydrangea can develop into a healthy and vigorously flowering beauty with the right fertilisation. In addition, with the popular Hydrangea macrophylla fertilisation is the foundation stone for the flower colour. The flowering is additionally influenced by the pH value of the soil.
When planting the hydrangea, an organic slow-release fertiliser should be incorporated. The slowly released nutrients and the activation of soil life are a good basis for the establishment of new planting at the new location. By the way, hydrangeas are planted either in spring (March – May) or in autumn (October – November). Older hydrangeas are fertilised once a year in the garden and twice a year in the pot due to the smaller substrate volume.
The right cut is indispensable for the magnificent flowers. Hydrangeas can be cut either in autumn or spring. In order to determine the right time, you should first know which hydrangea species you are dealing with. This is because Hydrangea macrophylla and Hydrangea quercifolia are already forming their flowers in autumn for the following year. They flower on last year’s wood. If you cut back too much, you may lose the beautiful flower. Panicled (Hydrangea paniculata) or smooth hydrangeas (Hydrangea arborescens), on the other hand, bloom on the so-called annual wood. This means that they form their flowers in the same year in which they bloom. Thus, these two popular hydrangeas are among the species that can be cut back unharmed.
In this article you can learn more about pruning hydrangeas.
As a rule, you can rely on the fact that all hydrangea species offered in stores in temperate climate zones are most likely reasonably hardy. Despite that, frost damage is unfortunately still possible and can affect the flowering of hydrangeas. In order to avoid this, you should consider the following:
- A protected place in semi-shade should already be chosen during planting
- A winter protection made of leaves, a jute sack, fir branches or mulch protects the plant (always cover the outer shoots close to the ground!)
- Fertilisation with mineral nitrogen is a big no-no from mid-July; organic fertilisers can be used until August
- The fertiliser used should have a sufficiently high potassium content, as this is essential for frost resistance
- Even if the temperatures rise, you should not completely remove the winter protection until the Ice Saints have passed (11th to 15th of May); have the jute bag ready for frosty nights; of course, it is possible and important to expose the plant during the first warm weeks
- Hydrangeas in pots should be protected in the same way as their garden bed counterparts
- In addition, potted hydrangeas should spend the winter in protected garden areas; pots with a diameter of less than 35 centimetres should be kept in a shed or a garage over winter without frost (3 – 5 °C)
Additional information on overwintering hydrange as can be found in this article.
For the vegetative reproduction of hydrangeas, access to an already existing hydrangea plant that one can to reproduce is needed. Vegetative propagation produces clones of the beloved hydrangea from your own garden. Basically, hydrangeas can be propagated either by division, layering or cuttings.
In this article you will find out how the aforementioned methods of the propagation of hydrangeas work.
Pests and diseases of hydrangeas
With good care, hydrangeas are generally not too susceptible to diseases and pests. Nevertheless, even with great care pests and diseases can occur. The most common issues with hydrangeas are the yellowing leaves caused by chlorosis and mealybugs.
If the leaves of your hydrangea turn yellow, the cause may be an iron deficiency, also known as chlorosis. Chlorosis is particularly common in hydrangeas. The cause is usually a lack of nutrients. The missing nutrient in hydrangeas is almost exclusively iron, although there is almost always enough of it in the natural soil. The reason for the deficiency is therefore not a lack of iron in the soil, but that the hydrangea cannot absorb the iron. Remedies for hydrangea iron deficiency are discussed here.
Mealybugs (Pseudococcidae) are a frequent pest on hydrangeas. They are very easy to spot because they are surrounded by a white web that resembles white hair or fluff. The mealybugs suck on the plants and then absorb the sap, transferring harmful viruses to the plants. The infested leaves turn yellow and eventually fall off. If the mealybug infestation is severe, the hydrangeas can even die. Click here to find out how you can control aphids on hydrangeas.
The impressive flowers of the hydrangea can be preserved and thus serve as a great decorative element. By drying, the decorative flowers can become a permanent companion in the home – even in months after the hydrangea season is over. It is important that the flowers are harvested in full splendour before they wither. Make sure that no flowers are likely to grow in the following year on the shoot from which you harvest the flower. The deeper you cut the shoot, the less likely it will be to flower next year.
Are hydrangeas bee-friendly?
As mentioned above, the actual flowers of the hydrangea lie in the middle of the beautiful mock flowers. These have a moderate supply of pollen and nectar. Unfortunately, the numerous hybrid forms and varieties of hydrangea are often completely uninteresting for pollinators. This is because breeding focuses on the ornamental value of the flowers rather than their nourishing potential for insects.
However, you can turn your garden into a paradise for bees with other bee-friendly plants about which you can learn in this article.