Plate hydrangea: planting, caring for & cutting

The plate hydrangea (also called sawn hydrangea) attracts attention with its umbrella-like flowers. We reveal what you should consider when planting and caring for them and give precise instructions on how to cut the plate hydrangea.

The plate hydrangea looks a little wilder and more original next to the lush garden hydrangea. Unlike some of their relatives, whose inflorescences are composed only of pseudo-flowers Plate hydrangeas also have numerous fertile flowers and are therefore a valuable food source for summer Insects.

Plate hydrangea: flowering time, characteristics and origin

The plate hydrangea (Hydrangea serrata) is also known under the names sawn hydrangea, Japanese mountain hydrangea or umbrella hydrangea and originally comes from the mountain forests of Japan. It grows as a sprawling semi-shrub and reaches a height of up to 1.5 meters. During the flowering period from July to October, the umbrella-shaped flowers gradually open. In the middle are the rather inconspicuous fertile flowers, which are surrounded by a wreath of pseudo-flowers. These are composed of four to five oval petals. Depending on the variety, the approximately 10 cm large umbrella panicles shine in white, pink, violet, blue or in several colors. In addition to the variety, the pH of the soil also influences the color of the flowers. The flowers appear pink on alkaline or neutral soils, while they have a blue tint on acidic locations. The opposite leaves of the plate hydrangea are bright green and taper to a point.

Hydrangea Varieties

The plate hydrangea variety 'Bluebird' is particularly well-known and popular. This is a short cultivar. It has purple inner flowers with blue stamens. The outer pseudo-flowers are pale lilac to blue in colour. Since flower color depends on the pH of the soil, it can vary slightly depending on the location. To get the blue color you can check out our related article, how to dye hydrangea blue.

Next to the Hydrangea serratavarieties, there is also a large variety of hybrid breeds Hydrangea serrata and Hydrangea macrophylla. These bear the species name Hydrangea macrophylla, but are very similar to Hydrangea serrata and are also called plate hydrangeas. This group includes the plate hydrangeas 'Lanarth White' and Endless Summer 'Twist-n-Shout'. The plate hydrangea 'Lanarth White' is very suitable as a container plant due to its small growth height and width of 90 to 120 cm. Its plate-shaped inflorescences are made up of white marginal flowers and pink or blue inner flowers, depending on the pH of the soil. The variety Endless Summer 'Twist-n-Shout' in the color pink impresses with its dreamy pink inflorescences, which contrast wonderfully with the dark green leaves.

Other hardy plate hydrangea varieties are Hydrangea macrophylla 'Dragonfly' and 'Pheasant'. The flowering panicles of the 'Libelle' variety look particularly elegant. Its pink inner flowers are surrounded by pure white marginal flowers. The flowers of the 'Fasan' variety appear in bright purple. If you can't decide on a color or are looking for something unusual, you might enjoy a multicolored plate hydrangea variety such as Hydrangea serrata 'Cotton Candy', whose pseudo-flowers are pink in color and have small creamy-white leaflets in the centre. If the soil pH is acidic, the pink can also turn into a delicate violet to blue tone.

Planting plate hydrangea: location and time

Like the closely related farmer's hydrangea, plate hydrangeas feel most comfortable in a partially shaded, wind-protected location in the garden or on the balcony. In principle, hydrangeas can be planted all year round, but the ideal time is between March and June.

Umbrella hydrangeas prefer a humus and nutrient-rich, fresh to moist garden soil with an acidic or at least slightly acidic pH value between 4 and 6. Acidic soil makes it easier for them to absorb nutrients, especially iron - planting in acidic soil prevents iron chlorosis, which is common in hydrangeas. Sandy, nutrient-poor and too alkaline garden soils should be treated with a suitable special soil like ours before planting Plantura organic acidic soil relocated or replaced over a large area. Very clayey soils should also be loosened up deep in the ground at the bottom of the planting hole with drainage material such as sand, expanded clay or perlite.

Carefully loosen the plant ball of the plate hydrangea from the plant container and then loosen it up a bit. This stimulates root growth. The plant ball is then placed in a sufficiently large planting hole or the prepared planter and this is filled with substrate. Press firmly and pour generously. A regular and sufficient water supply of newly planted plate hydrangeas is essential, especially when high temperatures occur frequently in early summer. In addition, a mulch layer of leaves or bark mulch can be placed around the hydrangeas to keep the moisture in the soil longer. In order to use the water even more efficiently, a circular watering rim can be made from the leftover garden soil the hydrangea plants are shaped, which prevents the irrigation water to the sides above ground drains.

Tip: Forest gardens and those on former moorland are often associated with a acidic soil - it is therefore worth checking the soil pH value before buying an acidic one special earth. However, the vast majority of garden soils in Germany do not offer optimal growth conditions for hydrangeas, which is why the humus-rich, acidic soil is often a good investment in beautiful hydrangea flowers.

If you want to plant the hydrangea in a pot on the terrace or balcony, an acidic soil like ours is suitable Plantura Organic Acid Soil also ideal as a substrate. In addition to the right soil, choosing a suitable bucket is also important. It should be large enough and the bottom of the container should have a drainage hole so that excess water can drain off easily and no waterlogging can occur. Glazed pots or plastic containers are more suitable than open-pored clay pots because they don't lose water as quickly.

Maintain plate hydrangea

Like all hydrangea species, plate hydrangeas have an extremely high water requirement and must be watered regularly in summer, and possibly even twice a day on hot days. In the case of pot hydrangeas in particular, care must be taken to ensure that the substrate does not dry out due to the smaller volume of soil. Umbrella hydrangeas are sometimes sensitive to lime. Therefore, it is best to use rainwater for watering. Not only do you do something good for your hydrangea, you also save valuable drinking water. If you don't have a water butt, tap water with a low lime content or water that has been acidified with a small amount of peat is also suitable. To get the most out of the water, in addition to the water-saving measures mentioned above, you should (Mulch layer and pouring edge) It is best to water in the morning or evening when the sun's rays and thus evaporation are low.

Cutting plate hydrangeas: This is how you proceed when cutting back

Plate hydrangeas are rarely cut. In the spring, the dead inflorescences are removed just above the new buds and Frozen or dried parts of the plant by hand or with scissors from the shrub solved. If the hydrangea grows too sprawling and bushy, it can be thinned out a bit by completely removing a few shoots at the base.

Fertilize plate hydrangeas

A separate fertilization is not absolutely necessary for plate hydrangeas in the flower bed if the garden soil is good and compost is occasionally supplied. In the case of pot hydrangeas, however, it is advisable to apply fertilizer every year in order to replenish the nutrient supply in the limited pot volume. Ours is suitable for this Plantura organic hydrangea fertilizer optimal with three-month long-term fertilization. It supplies the soil with extra iron and can thus prevent typical deficiency symptoms and diseases. Spring is the right time to fertilize plate hydrangeas. Spring fertilization gives the hydrangeas a good start to the growing season. If necessary, additional fertilizer can be added in summer, as described in our article on Fertilizing hydrangeas can read. In late summer and autumn or even winter, the hydrangea should not be fertilized, otherwise frost damage may occur.

tip: A layer of mulch, which keeps moisture in the soil for longer, improves the effectiveness of the hydrangea fertilizer. But be careful: hydrangeas have very shallow roots. Therefore, one should not work the fertilizer under the hydrangeas, as this could damage the roots.

Overwintering plate hydrangeas

Plate hydrangeas are hardy in our latitudes. Well-hardened plants from specialist shops are robust and usually do not require winter protection in the flower bed. However, it is not uncommon for individual shoots to die off every year and have to be removed. In rough locations, the flat roots can be protected from the effects of frost with a layer of leaves or fir branches. Plate hydrangeas growing in pots should be overwintered in a sheltered place, for example in the corner of a house, and possibly under a roof. In the case of prolonged low temperatures, a garden fleece or jute bag can be placed around the plants to protect them from frost damage.

Propagating plate hydrangeas

Like the related garden hydrangeas and other hydrangea species, plate hydrangeas can be propagated from cuttings. These are cut between June and July. 10 to 15 cm long, slightly woody and vital shoot tips without flower buds are cut off the rods. Then all leaves are carefully removed except for the upper pair of leaves and the cuttings are then inserted 2 to 3 cm deep into growing containers filled with substrate. A peat-free seed soil such as ours is suitable as a substrate Plantura Organic Herb & Seed Soil. With some sand or perlite, the substrate permeability is increased and improved rooting is achieved. The substrate in the growing pots must be kept moist at all times. The best way to moisten is with a spray bottle. In a bright place without direct sunlight and at a temperature that is as constant as possible of around 15 °C, the cuttings will take root and grow into new young hydrangea plants.

If you are also interested in other types of hydrangea, you can read our special article about panicle hydrangeas read on and get to know interesting varieties of this species.