Ortensia

Class

Dicotyledoneae

Division

Angiospermae

Family

Hydrangeaceae

Order

Cornales

Genus

Hydrangea

Species

macrophylla

Description

A medium-sized deciduous shrub, growing up to 2.5 metres tall. With a compact, globular habit, it has broad leaves, often dark green in colour, which enhance the visual impact of its elegant and colourful summer corymb-like inflorescences. Suitable for use in gardens, in flowerbeds and borders, as well as on terraces, in large pots and planters, and in combination with other ornamental plants. It prefers a cool climate, watering that prevents waterlogging, and regular but balanced fertilisation.

Varietal description

A shrubby plant with numerous branches and inflorescences. Very hardy, requiring organic, slightly acidic soil. It is highly striking due to its abundance of large flowers and long flowering period. Its dark green, glossy leaves provide a contrasting backdrop to the flowers. Suitable for planting as a solitary specimen in the garden or in a pot, or in rows to form colourful clumps and hedges as borders. A species with numerous varieties and flower colours: ranging from the palest shades to the most intense and dark hues. There are also varieties with variegated foliage.

curiosity and special features

The inflorescences of the hydrangea macrophylla, as well as playing a primary role in gardens and terraces, are also suitable for decorating our homes when cut, fresh or dried.

Origin and Diffusion

A species native to central and southern Japan and the Himalayas, it was introduced to Europe in the 18th century by the naturalist P. Commerson, arousing great admiration for its large inflorescences. Today, it is found in numerous varieties that differ in the colour tones of their flowers and leaves.

Leaf

The leaves have an oval lamina with a thick toothed margin.

Flowering period

Flowering lasts from early summer to late summer for a duration of 30 to 50 days.

Inflorescence

The Hydrangea macrophylla is distinguished by its globular corymb-like inflorescences, which give it considerable decorative appeal, making it a focal point in gardens and on terraces. The inflorescence consists of sterile flowers – often the outermost ones – and fertile flowers, with petals in different shades depending on the variety. At the end of the flowering period, the inflorescences often change colour, adding further decorative value, even when dried.

Leaf color

The leaf is solid-coloured, slightly tomentose on the underside.

Plant height

The plant grows to a height of between 1 and 2.5 metres and is ideal both as a single specimen and in groups, offering high ornamental value.

Lifespan

Polyennial deciduous shrub.

Suggested planting locations

With a broadly versatile use, it is suitable as a border plant , for pots, planters, gardens and parks, large flower beds and roadside roundabouts, open fields, green roofs, outdoor tubs

Stem/stem

The stem is semi-woody and often has distinct lenticels.

Flower

The flower is simple in shape and of medium size. It is arranged in large corymb inflorescences. It flowers from early summer to late summer, with a flowering period of between 30 and 50 days.

Growth

The globular growth allows for homogeneous and compact groups.

Plant habit

The developed habitus is bushy.

branching

The plant produces abundant shoots, resulting in a high density of inflorescences and foliage.

pH

It prefers a soil or substrate pH that tends towards the acidic side, with optimal values ranging from 6.0 to 6.5. The colour of the flowers often varies depending on the soil’s acidity level.

soil preparation

For transplanting in late winter ensure that the soil is not frozen. It is advisable to carry out light spading to remove any weeds present, and also to bury organic or slow-release chemical fertiliser for ornamental plants.

sun exposure

It is a plant that thrives inpartial shade or dappled shade, sheltered from direct sunlight, particularly during the hottest part of the day.

Ideal climate and temperature

The ideal temperature is between 0.0 and 30 °C for healthy growth and abundant flowering; it prefers a cool climate.

Use

The large-flowered hydrangea is a flowering shrub that is widely appreciated in the following areas of use:

Ornamental use Outdoor ornamental use Outdoor landscape design Landscaping For cut flowers, for cut foliage

Hardiness

It is moderately hardy.

Soil/medium

For use in the garden, the soil should be of medium texture, light and well-drained. It is important that the soil in which the plant is to be planted and take root is loose, rich in organic matter and well-fertilised. In pots or planters, use a new, high-quality potting mix for spring plants, based on peat and perlite.

Maintenance

Once the plant has become properly established at its new planting site, cultivation isfairly straightforward, with an overall average level of management effort required. Care should be taken to ensure suitable exposure and to water in such a way as to prevent waterlogging, whilst applying balanced fertiliser to maximise vegetative growth and ensure full flowering.

cultivation tips

Here are some useful cultivation tips specifically for Hydrangea macrophylla:

Balanced fertilisation Avoid over-watering Avoid direct sunlight during the hottest part of the day In summer, it prefers a shady spot to avoid drought stress and high afternoon temperatures Keep the soil consistently moist Prefers a cool climate Prune correctly

Composition

It is suitable both as a single specimen and in uniform groups, as well as in combination with other ornamental plants – whether herbaceous, shrubby or tree-like – to create compact, colourful arrangements. It can be combined with species of varying heights to create a sense of depth; colour combinations may feature shades of the same hue or an alternation of colours chosen from the various available varieties, allowing you to create patterns or designs according to your personal imagination. Taking into account the coordination of colour and texture, flowering times and soil and climate requirements, we recommend combinations with Digitalis, Rudbeckia fulgida, Phlox paniculata, Salvia, Nepeta, Azalea, Buxus, Camellia and Rhododendron. When transplanting, ensure an appropriate planting spacing and position each individual plant according to its growth habit, the height it reaches and the desired colour combinations.

planting

An average planting density of 4 plants per square metre is recommended for flowerbeds. When transplanting, take care not to damage the roots and position the plant so that the root collar is above ground level. Plant the young plants in potting compost or loose, light soil to encourage root development; firm the soil around the root collar and water thoroughly without allowing water to pool.

pruning

Do not prune young plants during their first year after transplanting, whether they are grown in pots, planters or in the ground. For established plants, prune at the end of winter using sharp, clean secateurs to make a clean cut, shortening the branches that have previously flowered, starting from the top just above the first pair of well-defined buds. Also remove any dead, old or damaged branches.

Reproduction/Propagation

Propagation can be carried out by layering, apical cuttings and node cuttings.

potting

If the plants are grown in pots or planters, the potting compost should be replaced every two years, or at least supplemented with fresh potting compost and organic fertilisers.

Irrigation

After repotting, water the plant without causing waterlogging. Thereafter, water regularly and in a balanced manner – even several times a week if the weather is very hot – taking care to avoid both overwatering and letting the soil dry out completely. Where possible, keep the plants in partially shaded areas, as they do not thrive in direct, very hot sunlight. Pay attention to the quality of the water used as well; rainwater is best, as hydrangeas require a slightly acidic pH and low salinity. It is advisable to water directly into the soil or growing medium, avoiding wetting the above-ground parts of the plant.

Fertilization

When preparing the soil for transplanting, apply a base dressing of a balanced, slow-release fertiliser for flowering ornamental plants. Once the plant has become established, if grown in the garden, it should be fertilised generously in spring and early summer with a complex, iron-rich fertiliser. Hydrangeas require a good amount of fertiliser both when young and as mature plants. Continuous and regular flowering depends on the nutrients and minerals present in the growing soil. Use fertilisers that also contain iron and magnesium to optimise flowering.

Edibility for humans

Non-edible.

advise 1

Hydrangeas require a good amount of fertiliser both when young and as mature plants. Continuous and regular flowering depends on the nutrients and minerals in the soil. Use fertilisers that also contain iron and magnesium to optimise flowering. In summer, reduce nitrogen (N) fertiliser and increase the amounts of phosphorus and potassium (P, K). Also use humic acids, which promote the uptake of nutrients, extend the duration of flowering and enhance colour intensity, as well as slightly acidifying potting composts.