Hydrangea arborescens is a plant species of the genus Hortensia of the Hortensia family, found in the wild in eastern North America. It is the most unpretentious and common species of the genus, which can easily withstand harsh winter frosts.
Planting and care of Hydrangea arborescens
- Flowering: Abundant, from mid-July to October.
- Planting: Spring before the buds swell or in leaf fall.
- Lighting: bright light in the morning, semi-shade or shade in the afternoon.
- Soil: moistened, rich, light, but fertile, well-drained, with pH 5,5.
- Watering: regular and abundant, especially in dry seasons: 1-2 times a week at a rate of 3-4 buckets of water per plant.
- Fertilizing: in the spring a handful of Kemira flower, and during the budding period make potassium-phosphorus fertilizers. By the end of the season, you can make 2-3 more fertilizers with a fertilizer with a reduced nitrogen content.
- Pruning: begin pruning in the fifth year: the main procedure is carried out in the fall, and in the spring do only sanitary cleaning and once every 6-7 years rejuvenating pruning.
- Propagation: by cuttings, grafts and bush division.
- Pests: spider mites and green leaf aphids.
- Diseases: powdery mildew, false powdery mildew and chlorosis.
Read more about growing Hydrangea arborescens below.
Hydrangea arborescens is a 1 to 3 m tall shrub with a rounded crown and slightly pubescent shoots. Hydrangea arboreal leaves are elliptic or ovate, 6 to 20 cm long, with serrated edges and a heart-shaped base, naked on the underside of the plate. Their upper side is green, the lower one is glaucous. Numerous sterile flowers, about 2 cm in diameter, together with small fruiting flowers, are clustered in shields up to 15 cm or more in cross-section. The white flowers have a greenish tint when they open, then the greenish tint disappears and by the end of flowering the inflorescences are pink. The fruit of Hydrangea arborescens is a capsule up to 3 mm in size. Blossoms are abundant and long-lasting from the first half of July to mid-autumn.
The culture is distinguished by its rapid growth, love of moisture, demanding to the composition of the soil and winter-hardiness. This species more easily than other hydrangeas, tolerates the presence of lime in the soil.
Planting hydrangeas tree hydrangea in the open ground
When to plant
The time of planting hydrangea tree type is chosen taking into account the climate of the area. In the north, it is better to plant it in early spring, before the beginning of the sap movement, as soon as the soil in the garden thaws, and in areas with mild, warm climate, you can plant hydrangeas as before the buds swell and after leaf fall.
What is the best place for the plant? Hydrangeas prefer well-lit areas in the first half of the day, which in the afternoon are in the shade. Hydrangea tree does not like wind: its flowers in blown through places quickly fade. The plant needs moist soil, so do not plant it close to trees and shrubs, so they do not absorb moisture from the soil intended for hydrangeas: the distance from the tree hydrangea shrub to any other plant should be at least 2 m.
How to plant
The best planting material is three- to four-year-old hydrangea tree seedlings. When buying seedlings with an open root system, pay attention to its condition, but it is better to buy planting material with closed roots. Before planting, water the seedling abundantly, take it out of the container and shorten its roots to 20-25 cm. If rotten or dry roots are found, it is necessary to cut them off as well.
When planting in poor soil, a hole is dug with a diameter of about 50 and a depth of 65-70 cm, but if the soil on the plot is fertile, the depth can be less – about 50 cm. In general, the size of the pit depends on the size of the root system of the seedling and the amount of soil on it. In the center of the hole, pour a mound of previously prepared soil mixture of humus, chernozem, sand and peat in a ratio of 2:2:1:1, adding 50-60 grams of complex mineral fertilizer. Place the seedling on a mound, spread its roots and fill the remaining space with the same nutrient soil mixture. Tamp down the surface of the planting strip and water generously under the roots.
Care of Hydrangea Arboretum
Hydrangea tree in the open ground requires regular and abundant watering, especially during dry, hot periods. In addition, you will need to loosen the soil in the root circle and remove weeds, make fertilizers in the soil, prune hydrangeas and protect it from diseases and pests.
Watering Hydrangea tree is carried out 1-2 times a week with water at a temperature of 20-25 ºC, pouring under each plant at least 3-4 buckets of water. If the plant does not get enough water, the leaves will droop and turn yellow, the flowers will dry out, and the hydrangea will lose its decorative effect. So make sure that the soil does not dry out. After watering or raining, carefully loosen the surface, taking care not to damage the shallow root system, while removing weeds. To protect the soil from rapid loss of moisture, you need to mulch the surface around the plants with a layer of peat or humus, and then water, and loosen the soil and weed you will have to much less often – about once every 10 days.
For hydrangea to be attractive throughout the growing season, you need to feed it with both mineral and organic fertilizers. Early in the spring in the root zone sprinkle a handful of Kemira floral, which contains not only the necessary for each plant nitrogen, phosphorus and potassium, but also a group of important trace elements. The second fertilizer, consisting of 30 g of potassium sulfate and 50 g of superphosphate per plant, is applied during the budding period. In the future, you can apply fertilizer 2-3 more times, but be careful with nitrogen, as its excess leads to a steady green hue in the flowers of hydrangeas. In addition, plants overfed with nitrogen do not winter well.
2-3 times during the spring, watering the soil in the root zone and spraying the crown with a weak solution of manganese solution. They do this to strengthen the strength of the shoots of Hydrangea tree, which can not withstand the weight of a large number of large inflorescences. You can, of course, tie the branches to the support, but this will not add to the attractiveness of the plant.
Of all the species of the genus hydrangea tree hydrangea is the most unpretentious and cold-resistant, but new varieties of the plant, brought from the nurseries of warm regions, require dry dip and light covering before wintering. Hydrangea bushes younger than four years old are covered with foliage or lapelwood. Shrub branches should preferably be tied together for the winter, so they do not break under the weight of the snow. But even if the plant will suffer from frosts, hydrangea tree in the spring is restored rather quickly.
Hydrangea tree forms inflorescences on the shoots of the current year. The first four years after planting, the plant is not pruned, but thereafter, pruning is done twice a year, in spring and autumn. The main pruning is the autumn pruning, during which all wilted inflorescences are removed.
If the hydrangea is not trimmed, the bush becomes too dense and has an untidy, neglected appearance. In spring, before the sap starts, do a sanitary sweep of the bush, removing weak, thin, frosty, withered, damaged and thickening the bush, i.e. growing towards the center, small or unable to flower weakened zero shoots. One-year shoots are shortened to 3-5 buds, from which new shoots with large inflorescences will appear in the current year.
Once every 5-7 years, rejuvenating pruning of hydrangea tree: in early spring, all shoots over five years old are cut at a height of 10 cm from the ground. However, the rejuvenation of very old plants is stretched for three years, otherwise they can die.
Pests and diseases
Hydrangea tree can be damaged by spider mites and green leaf aphids – sucking insects that feed on the cellular juice of the leaves and young shoots of the plant. There is no point in wasting time trying to destroy hydrangea pests with folk remedies, it is better to immediately proceed to the treatment of the shrub with a solution of acaricide. Good deal with sucking pests Aktellik, Fitoverm, Aktara, Sunmayt.
Of the diseases Hydrangea tree can suffer from powdery mildew, false powdery mildew (perasporose) and chlorosis. Fungal diseases are treated with fungicides. For example, if a whitish powdery mildew plaque appears on the leaves, Hydrangea should be treated as soon as possible with a solution of Bayleton, Quadris, Topaz, Fundazole or other drugs of similar action. The plant is treated against peronosporosis with the biofungicides Gamair, Alirin-B or Phytosporin. Solutions are prepared in accordance with the instructions of the chemical manufacturer, strictly observing the dosage and the interval between treatments.
As for chlorosis, which is manifested by discolored spots on the leaves, it usually occurs from an excess of humus in the soil or a lack of iron in it.
Hydrangea Hydrangea propagation
Hydrangea tree is propagated by cuttings, division of the bush and branches. Professionals also use grafting and the generative method for this purpose, but for amateurs they are too time-consuming, expensive and unreliable.
Dividing the bush Hydrangea tree can be both in spring and in autumn: the bush is dug up and disassembled into parts so that on each partition necessarily there were buds of renewal. The parts of the bush are planted in pre-prepared pits. If you spend the procedure in the spring, by the fall, the parts of the bush will already be rooted in new places.
Propagation by grafts
This is also a fairly easy-to-perform method of multiplication, which gives good results. In spring, annual shoots are bent to the ground, put in pre-made ditches to a depth of 10 cm so that the apex section of about 20 cm remains above the surface. The offshoot is fixed in this position, and the ditch is filled with fertile soil. Throughout the season, the offshoot is watered and nourished together with the mother plant, and in the fall or next spring it is separated from the bush and planted in a new place.
Propagation by spring and summer cuttings
This method of propagation of hydrangea tree is used most often. Spring cuttings are cut in early June so that at their base was a heel – a small part of the last year’s shoot. Summer cuttings are harvested in July from the apical, unpinned part of the shoot. Cuttings should have 1-2 internodes. The upper leaves on them are shortened by half, the lower ones are removed. For successful rooting in conditions of high air humidity, an installation producing fog will be required, and a soil mixture of two parts peat and one part sand is used as a substrate, although it is possible to root cuttings in leafy soil covered with a layer of sand 3-4 cm thick. Planting is done at an angle of 45º, and the greenhouse is covered with a transparent cover. Rooted cuttings spend the first winter in a cold greenhouse or basement, and in the spring they are planted in the ground. The next winter, cuttings are well covered with lapnik, and after a year they can already winter without shelter.
Varieties of hydrangea arboreal
Not many varieties of hydrangea arboreal are grown in garden plots. The best ones are:
- Hydrangea tree Grandiflora – a shrub with a height of 1.5-2 m with a crown up to 3 m in diameter. The leaves of the plant are light green, up to 16 cm long. Creamy-white flowers, up to 2 cm in diameter, are arranged in corymbose inflorescences up to 20 cm across. The abundant flowering lasts from June to September;
- Annabelle is a white hydrangea, tree-like, up to 1.5 m tall with a crown up to 3 cm in diameter and flowers up to 25 cm across. This variety blooms at the same time as Grandiflora. Annabelli’s annual growth is 20 cm;
- Hydrangea Pink Annabelle is a form of Annabelle with dark pink flowers that gradually turn bright pink;
- Sterilis is a variety with flowers collected in dense hemispherical inflorescences, the gravity of which bends the branches. At the moment of opening the flowers are greenish-white, then the green tint disappears and the inflorescences remain white until the very end, without acquiring a pink hue;
- Hayes Starburst, one of the newer hydrangeas, has narrower leaves than other hydrangeas and spherical flowers, up to 25 cm in diameter, which are white topped flowers;
- White Home – a bush up to 130 cm high with an oval beautiful crown. Inflorescences consist of small creamy-white fruiting and white sterile flowers. The variety is winter-hardy, its shoots perfectly withstand the weight of inflorescences and do not bend;
- Incredible is a tall and hardy variety, similar to Annabelle, but with even larger spherical creamy-white inflorescences with a faint yellowish-lime color;
- Invisibelle is the first Hydrangea with coloured flowers: it has dark pink blossoms which stay afloat until the end of the blossom, changing only their color intensity.
Hydrangea arborescens in landscaping
Hydrangea arboreal looks great in both single and group plantings. It harmonizes surprisingly with clematis, lilies and roses. Use the plant for the creation of tree and shrub compositions in combination with conifers and also as a hedge, not requiring forming pruning. However you decide to use Hydrangea arboretum, it will certainly grace your garden.
- Read about the subject on Wikipedia
- Features and other plants of the Hortensia family
- All Species List at The Plant List
- More information at World Flora Online