Garden

Growing hydrangeas


Cultivation


Hydrangeas are generous, strong and extremely adaptable plants. They love the shadow, but they grow well even in the sun, they live almost in every type of soil and the only two mandatory conditions for their cultivation are a regular supply of water and good drainage. A rich and rich earth is preferable to a sandy one and poor in humus, which can however go well with the addition of a mixture of leaves, chopped peel and manure. The materials that allow the hydrangeas to grow and thrive are therefore extremely available: acid peat, chopped bark or even the pruning of bushes and thin branches of trees reduced to small pieces. They do not fear the rigors of winter and generally resist well up to six or seven degrees below zero, making cultivation easy even where the winter climate is rather rigid. The subject of pruning is quite simple. As for the H.macrophylla, which bloom on the wood of the previous year, it will be limited to a cleaning of the dry, to the removal of the old flowers and to the cutting of the weakest stems that will take place removing the last couple of buds. The common opinion is that the old flower should not be taken away until spring, because it is thought to protect the new shoot; however the lacecaps lose almost all their flowers with winter frost. It is also a good habit, in plants of five to six years of age, to remove about a third of the hunts at ground level so as to give light even to the inside and allow a good lignification and vigor (usually the oldest hunts are removed ). Concerning H. paniculata and H. arborescens, which bloom on the wood of the year, they will leave two eyes at the base of each stem (February-March), laying the foundations for a flowering with very large panicels. Vines, on the other hand, require limited pruning, which serves more than anything else to contain their growth. For H. aspera, H. serrata, H. involucrata and H. quercifolia only reordering pruning. Pruning is not essential for hydrangeas: if left to grow in its natural state (limiting itself in the spring to remove the branches and dried flowers) we will have large and exuberant bushes with irregular shapes, with abundant flowering and smaller flowers. As far as reproduction is concerned, except for some more problematic species (H. aspera, H. seemani), which can be optimally reproduced by cuttings, to be carried out from April to October. Also the system of the division of the roots, easy and safe, is not to be discarded, and finally the method of sowing (November-December) which, while giving satisfactory results, does not guarantee the purity of the cultivar. A little more complex is the discussion about the question of ph, which establishes the factor of soil acidity and consequently determines the color of the inflorescences, whose variation, however, concerns only H. macrophylla and H. serrata.

Hydrangea description



The hydrangeas are very different from each other, both as bearing and for inflorescences.
These have no petals, but sepals that have changed by color. What we call the "flower" of the hydrangea is actually a set of tiny flowers, made more evident by the colored sepals. Within the inflorescence we can distinguish between sterile flowers and fertile flowers. The first are those with large, very showy sepals. The others barely notice each other. Sometimes the inflorescences contain only sterile flowers (in the macrophylla mophead, large roundish inflorescences) other times both (in those with lacecap shape, flat inflorescence).
Then there are also those "paniculate" in which the group of flowers takes the form of a panicle: they contain both sterile flowers and fertile flowers.
However, more and more various inflorescences are found: with only the margin of the colored petal, with small and incurved petals that appear almost curly.

Hydrangea variety



If you want to place a hydrangea in your garden it is really worth taking into consideration the plants that have recently arrived in our nurseries and that until recently were very rare, especially the Japanese and American varieties.
Here are some:
Arborescens
It is a shrub with an average height of 1.5 m. It is very rustic and the flowers open from summer to autumn remaining decorative for a long time. It is very well suited for both exposure and substrate.
A very well known cultivar is "Annabelle".
paniculata
They have white or pink flowers collected in pannicoli. They can also become very large (3-5 meters), but you can decide to control their size with pruning, which can also be very drastic. They resist egragialy at low temperatures.
quercifolia
They are plants originating from the North American continent: interesting both for the leaves and for the branches. The first ones have a lobed shape and take on very warm autumn colors, as well as the stems during the winter. They carry flowers to cream-colored panniculus and reach 2 meters in height
Serrata
They come from Japan and are usually quite small in size. They are decorative due to their elegant flowers mostly from the lacecap form. A further advantage derives from the bright colors that the leaves take on during the autumn. They are really precious when you want a garden that is always colorful even when winter is approaching. In this variety we can find among the most beautiful blue hydrangeas (eg Blue bird, Mont Aso, blue billow, blue deckle).

Variety of climbing hydrangeas


They do not belong to a single species. What characterizes it is the posture. They manage to climb thanks to small suckers. They are an excellent flowery alternative to ivy, American vine and clematis, especially for shady positions. The flowers are generally white with lacecap. They do not require great maintenance, but you have to wait at least a few years to see the real force.

Hydrangea display


Almost all the hydrangeas love a shady exposition, they are not particularly afraid of the morning or evening sun. It is good, however, for a good cultivation to be repaired during the hottest hours of the day, especially during the summer season, to prevent direct sunlight from ruining them.

RusticitŠ°



Most of the hydrangeas are very resistant to frost. However the most resistant, which can also be grown at high altitude, are undoubtedly the paniculata and arborescens. The petiolaris and quercifolia climbers are also excellent. The greatest danger is actually, for the most sensitive, spring frosts that can burn the buds with the consequent loss of flowering for that year.

Irrigation


The hydrangeas require abundant watering and it is good during the summer to proceed with a certain regularity. However, water stagnation that can damage the root system must be carefully avoided as well as making the iron more difficult to absorb, increasing the risk of chlorosis. You should not be too alarmed if the plant, in the hottest hours of the day, should appear dehydrated and tired. Most of the time with the cool of the evening it will return to its normal splendor.
If the problem persists until the morning (and we also notice some burns on the leaves) it is better to shade the plant in some way and mulch the soil to avoid an excessive dispersion of humidity.

Land for hydrangeas



If we want to grow hydrangeas in the garden we must think that their ideal soil must remain moist for a long time, but not favor water stagnation. The ideal is that it is moderately clayey and rich in organic substance. Sandy, stony or too clayey and compact substrates should be avoided. It is good to intervene previously working long on the ground and inserting soil conditioners to make the substrate more suitable.
If we did not have the time we could eliminate a large amount of land replacing it with a more suitable for acidophilic plants added with a good dose of organic fertilizer. In pot the ideal is to use the specific substrates for acidophilic plants with the addition of drainage compounds such as perlite, expanded clay or pumice.

Fertilizing


Hydrangeas need a good dose of soil conditioner. The best time to provide it is before the end of winter. The ideal is to spread it around the plant and then incorporate it into the soil with a light hoe. This will make the soil more alive and rich in microorganisms (which work in symbiosis with the roots) as well as being more capable of retaining the right amount of water. At the end of the cold season, we can also intervene with a slow release granular fertilizer for acidophilic or specific for hydrangeas to be distributed around the plant. It must be mixed with the soil to favor mineralization and to prevent run-off.

Supplements, soil acidity and flower color



Not all hydrangeas have the ability to change the color of their flowers. For example, those with white flowers and some red ones cannot. Also some may have a more beautiful blue point than others and the same is true for some very beautiful varieties only in pink.
If our soil is basic it will be difficult to get nice blues. Often, despite the efforts, you get to have a broken blue, multicolor flowers or a funeral violet. The advice is therefore to go towards the color that is in that most congenial terrain to the plant. If it is alkaline we try to enhance the pink. If we have an acid soil we try to get a nice intense blue.
A pH 6 is generally sufficient to obtain blue. To have it very intense, however, it is essential to supply the plant with aluminum sulfate (it is the absorbed aluminum that gives the color to the flower). And it is precisely this that is insoluble and therefore not accessible to the plant in soils with a pH higher than 6. It is found on the market under the name of "bluing". Traditionally, to get the color change in the hydrangeas, it was advised to insert nails or iron filings in the ground. It is an ineffective method if the soil does not have the right pH. Only by changing that will we make both iron and aluminum more available to our plant.

Leaf chlorosis


As we have said, hydrangeas love at least sub-acid soils. In the absence of these the leaves will tend to yellow, especially the veins. It is a significant problem because this coloring influences chlorophyll photosynthesis and therefore the plant's ability to grow and flower. To avoid this, it is necessary to intervene already from the end of the winter by spreading iron sulphate weekly on the ground. However, it is a treatment that gives little results because the soils are a buffer system and tend to return to their initial pH. The administration by chelated iron irrigation is very effective. Already with few applications you can see good and lasting effects. However, products that act in a wide pH range should be sought. For an emergency treatment there are also products suitable for foliar use. Care must be taken to carry out the treatments in the early hours of the morning or in the evening because the active ingredients degrade quickly if exposed to light and heat.

Pruning hydrangeas



To have beautiful hydrangeas it is good to learn not to intervene too much on them: it is often exceeded and people are seen pruning the plants every year at ground level. The most widespread varieties (such as macrophylla and serrata) bloom on the branches of the previous year. It is therefore good to limit oneself to eliminating only the oldest and most disordered branches, at most one third of the total, at the end of winter, and to eliminate only the dry flower in the others. Other species such as paniculata and arborescens can be pruned more drastically because they bloom on the branches of the year. Climbing varieties, involucrata and quercifolia may not be pruned, except to give the plant a more ordered general appearance.

Pruning hydrangeas


To have beautiful hydrangeas it is good to learn not to intervene too much on them: it is often exceeded and people are seen pruning the plants every year at ground level. The most widespread varieties (such as macrophylla and serrata) bloom on the branches of the previous year. It is therefore good to limit oneself to eliminating only the oldest and most disordered branches, at most one third of the total, at the end of winter, and to eliminate only the dry flower in the others. Other species such as paniculata and arborescens can be pruned more drastically because they bloom on the branches of the year. Climbing varieties, involucrata and quercifolia may not be pruned, except to give the plant a more ordered general appearance.

Hydrangea cultivation: Hydrangea diseases



The most frequent are powdery mildew, botrytis, leaf spot and root rot.
For oidium it is essential to promote air circulation and avoid wetting the leaves.
If we know that our plant is a victim of this disease every year, it is good to intervene after the spring rains by vaporizing sulfur. If the attacks were particularly strong, they can be treated with specific products. For botrytis and leaf maculatation, water stagnation must be avoided and possibly treated with suitable fungicides. Even for radical rot and collars the main advice is to avoid stagnation at all. If they appear, you can try to stem the problem by cleaning the base and spraying cupric or specific products. However, if they were very common, it is good to explant the specimen and restore the area by completely changing the soil.
Hydrangeas can also be attacked by insects. In these cases it is good to intervene with contact insecticides (for aphids) or even systemic + mineral oil (in the case of scale insects).
Watch the video
  • Blue hydrangea



    The hydrangea, in some of its then known varieties, arrives in Europe in the mid-1800s from the Asian regions of

    visit: blue hydrangea
  • Pink hydrangeas



    The hydrangea belongs to the Hydrangeacaeae family and its origins are Asian. In China, they currently come

    visit: pink hydrangeas
  • Hydrangea plant



    Hydrangea is the common name of Hydrangea, a genus of plants originating in eastern Asia, especially China, Japan

    visit: plant hydrangea
  • Hydrangea plant



    The hydrangea is a plant that both in nature and in pot has an explosive bloom. To keep the flowers longer p

    visit: hydrangea plant