Agricultural engineering and pruning of hydrangeas

Agricultural engineering and pruning of hydrangeas

Read the previous part. ← Large-leaved, petiolate and variegated hydrangea

Growing hydrangeas in the North-West of Russia, part 4

Hydrangea requirements for growing conditions

Large-leaved hydrangea

Agrotechnology is, first of all, meeting the requirements of plants for growing conditions. For hydrangeas, these requirements are quite specific, but in general, these plants are unpretentious, easily adapt to different conditions and grow well in our gardens.

All types of hydrangeas have similar requirements for growth conditions, mainly differing in cold resistance and the degree of shade tolerance.

Heat mode

The most cold-resistant are paniculate and variegated hydrangeas. Their shoots ripen well by autumn and are not damaged by frost even down to -40oС. They are not sheltered for the winter, only the root system requires protection in snowless frosts. Treelike hydrangea is not very cold-resistant, but after cutting off frozen shoots, it quickly recovers and blooms in the same year.

Large-leaved, serrated and many other rare hydrangeas in our country are not winter-hardy enough and require, depending on the variety and growing conditions, light or thorough shelter. Many varieties do not winter outdoors at all. In large-leaved hydrangeas, young leaves and flower buds often freeze during late spring frosts. Because of this, hydrangeas may not bloom this year.


All hydrangeas are moisture-loving, they need systematic, abundant watering, soil mulching... These care measures are especially important when planting in sunny places, on sandy soils. More than others, large-leaved hydrangea is afraid of drying. Large panicle hydrangeas can tolerate a fairly long drought. Most hydrangeas, except for the large paniculate ones, are not too afraid high groundwater... In order for the roots not to penetrate too deeply into the soil and suffer less from groundwater, hydrangeas need to be transplanted and divided in a timely manner.

The soil

Hydrangeas have quite specific soil requirements: they all prefer moisture-consuming, breathable, slightly acidic and even acidic soil. Required adding peat to the soil, humus, but not manure. Do not add lime to the planting pit. On neutral and especially alkaline soils, leaf chlorosis (yellowing) is possible, associated with poor absorption of iron in such conditions. You should not overfeed hydrangeas with nitrogen, as this delays the growth of shoots, worsens their ripening and, therefore, reduces winter hardiness. Potassium promotes better flowering and increased winter hardiness of hydrangeas, but it is better to introduce it in the form of potassium sulfate. When ash introductionrich in potassium, the acidity of the soil decreases, which is unfavorable for hydrangeas. On acidic soils, phosphorus is less assimilated, so it is pointless to add it in large quantities.

In colored large-leaved hydrangeas, the acidity of the soil and the presence of various chemical elements in it, primarily aluminum and iron, affect the color of the inflorescences. A more acidic soil and a higher concentration of aluminum and iron salts in it shift the color of hydrangeas to the blue side. A decrease in soil acidity and an increase in phosphorus concentration cause hydrangeas to turn pink or red.

All these subtleties are best taken into account when preparing a site for planting hydrangeas. Otherwise, it will be quite difficult to change the situation with the color of the inflorescences with subsequent measures for caring for large-leaved hydrangea. On the poor sandy-podzolic soilsrich in iron, old varieties of pink large-leaved hydrangea are bright blue in color. If there is a desire to turn a pink hydrangea into a blue one, you need to increase the acidity of the soil by adding sour peat, sphagnum moss, and coniferous litter to it.

It is possible to increase the concentration of iron in the soil by watering the bushes with a solution of ferrous sulfate (50 grams per bucket of water), and to increase the concentration of aluminum, potassium-aluminum alum or aluminum sulfate is used. To water the bushes to change color, you need to several times before staining the inflorescences. Repeat watering in the fall to affect the color next year. The burying of nails and other iron recommended in some articles in order to change the color of the hydrangeas is useless. The composition of the soil cannot be influenced by the white color of all types of hydrangeas.

Choosing a place and planting hydrangeas

Serrated hydrangea

The place for hydrangeas must be chosen based on their requirements for growth conditions and achieving maximum decorativeness. The correct choice of place for panicle hydrangea is especially important, since it grows for a long time in one place and does not tolerate transplanting in an adult state. The rest of the hydrangeas can be transplanted several times, choosing the most suitable place.

Hydrangeas do not like windy places, it is advisable to plant them near buildings, but not too close, so as not to increase the danger of freezing of the root system in winter. It is also necessary to protect the fragile panicle hydrangea from snow falling from the roof. When choosing a place for a large-leaved and serrated hydrangea, you need to consider the convenience of a winter shelter. Without this, caring for hydrangeas will be significantly complicated.

Planting all hydrangeas is best in spring. Hydrangeas that have wintered in the ground can be planted immediately after the ground thaws, and those obtained from greenhouses, with leaves, can only be planted after the end of the frost. The planting pit should be spacious enough - from 50x50 cm to 80x80 cm, depending on the size of the plant.

On light sandy soils, it is good to put clay on the bottom, and if water stagnation is possible, drainage is required. With a high standing of groundwater, plants should be planted in an elevated place, which is especially important for paniculate hydrangea. The pit must be filled with a soil mixture with the addition of peat, sand, humus, superphosphate, potassium fertilizer (50 g per pit). Mineral fertilizerscontaining nitrogen, add in small amounts (20 g per pit). There is no need to add fresh manure and lime. A panicle hydrangea with a pronounced stem is best planted to the level of the root collar. The rest of the hydrangeas should be planted with a slight deepening.

Pruning hydrangeas

All types of hydrangeas are beautiful in their own way, but to preserve these plants in the garden for many years, for annual and abundant flowering, hydrangeas, like no other plants, need careful and, most importantly, correct pruning ... The correct pruning determines how decorative the plant will be, and how abundant the flowering will be. Pruning largely determines the size of the inflorescences. If pruned incorrectly, large-leaved hydrangeas may not bloom at all. In addition, as a result of pruning, the bush is formed in accordance with the design intent.

The main pruning of hydrangeas is done in the spring. In the fall, most species do not need to be pruned. It is only important to cut off the faded inflorescences on paniculate hydrangeas, which reduces the breaking off of branches. Heat-loving hydrangeas are pruned in front of the shelter, primarily to facilitate work. Sometimes it is convenient to transfer part of the main pruning to autumn. The timing of spring pruning is not very important. It is usually carried out after the snow has melted before the leaves begin to grow back.

I did not observe the outflow of juice noted by some authors during late pruning. As for other shrubs, after unfavorable wintering and freezing, pruning is best done at a later date, when the degree of damage to shoots and buds is better visible. It is better to rejuvenate old bushes with cutting of large branches at an earlier date. The formation of plants, their pruning are determined by the characteristics of the growth of shoots and the setting of flower buds on them. These features are very different for different types of hydrangea, so we will consider pruning separately for each of the main types.

Tree hydrangea

Treelike hydrangea is a typical shrub with a high shoot-forming ability, a large number of zero shoots. Therefore, it usually forms as a free growing bush. After planting, the shoots are usually shortened for better growth of the bush. Treelike hydrangea blooms profusely at the ends of the shoots of the current year, and these annual shoots are formed along the entire length of the shoots of the previous year, as well as on older wood and even on underground shoots (zero shoots). The strongest null shoots can be flowering. This allows the hydrangea to be heavily pruned without affecting the flowering.

On a tree hydrangea, all types of pruning are carried out annually, carried out on most shrubs. Let's consider them in the sequence in which they are carried out in practice.

Sanitary pruning - for a tree hydrangea, this is mainly pruning the frozen ends of last year's shoots and broken branches.

Anti-aging pruning - cutting of branches older than 3-4 years of age to the base and, first of all, those on which there were weak growths last year.

Thinning pruning - cutting of weak zero shoots, small shoots that are not capable of flowering and thicken the bush.

Pruning for flowering - shortening of the growth of the last year, leaving 2-4 pairs of well-developed buds on them, from which strong flowering shoots grow in the current year. It is possible to trim all shoots at a certain height to give the bush a more regular compact shape. Often after frosty winters, sanitary pruning of frozen shoots replaces all types of pruning.

Similarly, tree-like species are cut off and some species close to it: motley hydrangea, ash and others.

Tatiana Popova, gardener
+7 (904) 631-55-57, +7 (812) 272-87-66
Photo by the author

Read all parts of the article Growing hydrangeas in the Northwest
Part 1: Types and varieties of hydrangeas, tree hydrangea
Part 2: Panicle hydrangea: varieties and features
Part 3: Large-leaved, petiolate and variegated hydrangeas
Part 4: Agricultural engineering and pruning of hydrangeas
Part 5: Hydrangeas in garden design

When to open hydrangea in spring

Proper preparation of hydrangeas for winter allows you to keep these flowers for a long time in your garden. This process includes pruning plants in the fall and sheltering the plantings. Preparation for winter begins in September, when some of the lower leaves are cut off. Before the onset of frost, the hydrangea is carefully bent to the ground, sprinkled with dry leaves and covered with any material, for example, lutrasil. In this form, the plants perfectly tolerate the winter.

With the onset of warm spring days, you should not rush to remove the shelter from the hydrangea. At this time, night frosts are possible, so this process begins to be done only in the second decade of May. At this time, the leaves are already being removed and the shoots are gradually beginning to rise. You can get rid of the covering material much earlier in order to prevent the blooming of flowers. Having freed the hydrangea from the winter shelter, it is covered with a film at night. It protects plants from recurrent night frosts.

Also, there is no need to rush to prune old damaged and twisted shoots in the spring. This can be done in June.

On some plants, you may notice that the shoots have darkened. Do not be upset, over time they will take on a normal color and turn green again.

Compliance with the rule for late opening of hydrangeas in the spring allows these plants to gain the necessary strength for rapid growth and beautiful flowering. At the same time, in order for the shoots to become solid and dense, the hydrangea must be regularly watered with a weak solution of potassium permanganate. It will also increase the resistance of the flowers to various diseases and pests.

Propagation of hydrangea by layering

I propagate treelike and panicle hydrangeas by layering.

  • In the spring, I put a horizontal low-lying branch in the groove, pin it, cover it with earth, leaving the tip.
  • In the panicle hydrangea, I preliminarily clean the bark at the dig site.
  • I water it thoroughly.
  • After a year, the branch gives excellent planting material.
  • You can forget about the dug-in branch for two years, so that the seedling grows stronger.



Cuttings are taken in April-June: annual green shoots 10-12 cm long are chosen from the crown, cut at a right angle. Leaves are removed from the lower part of the cuttings, treated with a growth stimulant and planted in a fertile soil mixture on a distribution ridge in a greenhouse. The first year after disembarkation (already in a permanent place) is covered in the winter, the flowers are cut off.

Young seedlings of hydrangea

Winter cuttings can only be carried out with large-leaved hydrangea. To do this, in October, you need to dig out the parent plant and plant it in a pot, put it in a room with a temperature of 0. + 2 ° C. In January, the temperature is raised to + 7 ... + 10 ° C. In February, the shoots of last year have already ripened, and cuttings with 2 internodes are cut from them. The lower leaves are removed, the upper ones are cut off, leaving half of the leaf plate. The lower cut is treated with a root formation stimulator and the cuttings are planted in pots with a nutritious soil mixture. Cover them with plastic bottles, glass jars.

By dividing

Hydrangea can be propagated by dividing in spring and autumn. The plant is dug up and divided into several parts so that each division has a bud of renewal, after which it is planted in prepared places.


Shoots no older than 1 year are bent to the ground and buried in, leaving a top about 20 cm long on the surface.In the spring or autumn of next year, the rooted shoot is separated from the mother bush and transplanted.

Hydrangea is rarely propagated by seeds and grafting.

1. Top dressing with mineral fertilizers (it is necessary to fertilize in moderation, since voluminous inflorescences can break or bend the branches of the bush).

3. Watering. Remember: the acidity of water for irrigation is recommended not higher than 5.6 pH.

4. Hydrangea is very hygrophilous, it must not be overdried.

5. Loosening of the soil: from 3 times per season to a depth of 5-10 cm.

Hydrangea care


The bushes are cut in the spring when the buds are swollen. For successful wintering, young shoots are pruned to 4 buds. Old bushes are renewed by root pruning. With targeted formative pruning of cuttings for 4-5 years, you can get a beautiful little hydrangea tree.
In the first year of flowering cuttings, flowers must be removed, this will help the plant gain strength and bloom profusely next year.

Changing the color of flowers

Large-leaved and new varieties of hydrangeas can change the color of the flowers. (excluding whites or reds). To do this, use various dyes sold in fertilizer departments.

If you want to get blue shades, then 2 times a week when watering, use crystals of aluminum or iron or aluminum sulfate (1 tablespoon per 5 liters of water).

For a pink color, a solution of potassium permanganate is used.

Peat can also affect the color change of hydrangeas. To do this, you need to water the plant with peat infusion, besides, it is also a good fertilizer.

Special additives will help to change the color of hydrangea inflorescences

Shelter for the winter

With the horizontal shelter of the hydrangea for the winter, you preserve the flower buds that are laid on the branches of the plant (in species that bloom on last year's shoots). Then the hydrangea will bloom early.


If a misfortune has happened to your hydrangea - the disease has overcome or it does not bloom - take a look at the section Questions about hydrangeas: there are collected answers from both experts and amateur gardeners.

Choose seedlings of various types of hydrangea in our catalog, which includes offers from various online stores of planting material.Choose hydrangea seedlings.

This article discusses the species that take root and grow in our latitudes.

Planting hydrangeas by cuttings

If you want to propagate hydrangea by cuttings, then cuttings should be prepared in April. Green sprigs of hydrangea are planted in fertile soil. You can use root or other root stimulants for better rooting. Once the cuttings are rooted, they can be transplanted into a school (breeding bed). Rooted cuttings of hydrangeas will grow in school for 1-2 years before being planted in a permanent place.

Young rooted plants require increased care. So in winter they are sheltered from frost with spruce branches.

Panicle hydrangea - outdoor care before wintering

Panicle hydrangea, the care of which in autumn is important for future flowering, will be happy with the last, fourth in a row, top dressing of the season. It is easiest to use ready-made preparations as fertilizers. If you wish, you can prepare top dressing yourself. To do this, dissolve 1 tablespoon in 10 liters of water. superphosphate and potassium sulfate and pour under the bush. A second procedure is not required.

You can also dig a bucket of compost or humus under the panicle hydrangea bush, which will not only saturate the soil with useful substances, but also warm the roots of the plant in winter.

There is no need to water the hydrangea in the fall. The exception is very dry weather, but this is rare in the middle lane. If you continue watering, then with the onset of cold weather, cracks may appear on the shoots from excess moisture.

When the panicle hydrangea has shed its leaves, carry out prophylactic treatment against pests with a 3% solution of Bordeaux liquid.

Watch the video: Pruning Hydrangeas Shrub u0026 Tree Form, Hellebore Cleanup u0026 More Sweet Pea Planting!