Aucuba - Aucuba japonica


The Aucuba

Aucuba is an evergreen shrub plant native to the Asian continent; currently it is also widespread in America and Europe in areas where the climate is temperate thanks to its very beautiful and decorative leaves and its colorful fruits. The Aucuba is grown mainly as a garden and apartment plant for ornamental and decorative purposes. Today on the market we find many hybrids created by man, with mottled leaves of various colors, the best known is the Aucuba Japonica. The characteristic of this plant is to be dioecious, that is, to have male and female flowers not on the same plant, therefore fertilization cannot take place except through the wind or insects. Aucuba is a very resistant plant that lends itself to being grown both indoors and outdoors; prefers a temperate climate and does not like temperatures above twenty degrees, does not fear the cold and can withstand temperatures of fifteen degrees below zero even if, during the harsh winters it would be advisable to keep it in a sheltered place, it is able to resist even in polluted environments where other plants would not make it. It would be better not to expose the plant to full sun during the hottest hours.

This plant grows very bushy. Branches and stem have a bright green color. The leaves of the Aucuba are shaped like an elongated spear, can reach a length of seven centimeters, have smooth or serrated edges and have particular mottling depending on the species. The flowering period of the Aucuba is from April to May, the flowers are small and have a green color, they grow together in panicles and, during the winter period, are replaced by very beautiful and decorative red berries that last many months. while the seeds reach maturity between October and February.

The Aucuba was brought to Europe by John Goefer, a botanist who understood that he had only imported plants with female flowers and therefore could not obtain a reproduction of the same; only fifty years later the species could spread thanks to the introduction of male specimens.


Species and Varieties

The genus Aucuba is divided into three species from which different hybrids derive:

Aucuba Japonica: as mentioned in the previous paragraph, this species is the most cultivated and widespread, generally it reaches a height of about three meters but, in pleasant soils and climates, it can even reach fifteen meters. The leaves of this species are oval in shape, glossy in appearance and with serrated edges. The fruits are red berries that reach maturity in the months of October and November. This species has some varieties created by man through crosses:

Aucuba Japonica variegata, a hybrid that has leaves with yellow spots; Aucuba Japonica picturata, whose central leaves have a yellow spot; Aucuba Japonica crotonifolia, with yellow streaks that occupy most of the leaves.

Aucuba Chinensis: it is a shrub species that can reach six meters in height, the branches are covered with short and simple hairs, while the leaves have a light green color in the lower part and darker in the upper one, elliptical in shape and serrated outlines , they can be up to twenty-five centimeters long. It develops spontaneously in the forest areas of Asia. Like the Aucuba Japonica, this species also has some varieties: angustifolia, obcordata, subintegra.

Aucuba Himalaica: this species comes from the Himalayas, has oval-shaped leaves with rinds without indentations and mottling.


Soil and cultivation techniques

The soil most suitable for Aucuba is deep, rich in humus, acidic and very well drained in order to avoid the formation of water stagnations which are very harmful for this plant; it is able to withstand even dry soils and periods of drought. The repotting operation should be done every two or three years; in the case of open field cultivation, organic matter will be added to the soil to favor the luxuriant development of the plant. The ideal arrangement of the Aucuba is in an area of ​​partial shade, if grown in an apartment it will be placed in a fairly bright and cool area, the soil must be mixed with peat, not calcareous. A very important operation, if you grow the plant indoors, will be to clean the leaves to avoid the formation of dust that would make the plant suffer; when the temperatures are pleasant, place the Aucuba outdoors.


Multiplication

The multiplication of Aucuba occurs by cutting or by seed, the latter technique, as mentioned several times, presents the problem of the uncertainty of obtaining new seedlings equal to the mother plant; if you had this purpose it would be better to choose multiplication by cutting. The best time to take Aucuba cuttings is October-November, they must be about twenty centimeters long; we will proceed with a clean cut below the knot with a sharp and clean knife. Once the cuttings have been taken, they will deprive themselves of the lower leaves and will introduce themselves in a powder that favors the development of the roots and, subsequently they will be placed in a soil mixed with peat and coarse sand that favors the drainage of excess water. he will water the soil until it dries up. When the first sprouts appear, the seedlings will have taken root and will be ready to be transplanted and cared for as adult plants.

The sowing process can be done in pots or seedbeds in October, the soil must be composed of fertile substance and coarse sand. The seeds are small so they will not be deeply buried, about half a centimeter will be enough. After sowing, the container must be placed in a shaded area at a temperature of about fifteen degrees, making sure to keep the soil at the right humidity. At this point we will cover the container with plastic so that it maintains the right temperature and the soil does not dry out too quickly. When the seedlings are sprouted, the plastic will be removed from the container and placed in a brighter area. By the time the new shoots have reached a height of about six centimeters, they will be ready to be gently transplanted.


Fertilization and Irrigation

The Aucuba must be fertilized in spring and summer during the vegetative development while in the cold season it is not necessary; the fertilizer must be of the liquid type containing all the substances and elements essential for a correct and healthy development of the plant: nitrogen, phosphorus, potassium, iron, manganese, copper, zinc, boron, molybdenum. The fertilization operation must be carried out about once a month, taking care not to overdo it with the addition of fertilizer because it could cause a weakening of the plant. Although we have previously said that this plant tolerates drought periods well, normally, during the hot seasons, the Aucuba needs to be watered abundantly, always taking care not to overdo it and to let the soil dry before proceeding with a new watering. , while in winter the water intake must be decreased.


Pruning

In most cases, a pruning is enough to eliminate the parts of the plant that are dry, weakened or damaged; however, when the Aucuba has reached a few years of age, it would be advisable to proceed with an aesthetic pruning operation that will provide it with a more regular and harmonious posture.


Diseases and Parasites

The Aucuba is a rustic and very resistant plant, however it can be subject to the attack of some pests and diseases. Below we will talk about the main attacks it can be the victim of and the possible remedies. For example, if you notice that the leaves seem burnt, this will certainly be a symptom of too long exposure to the sun, promptly remedy by placing the plant in an area richer in shade.

If dark, almost black spots appear on the leaves, it could be a symptom of too dry or compact soil, in this case, always paying attention not to cause water stagnation, proceed with an increase in water supply.

The presence of dark spots on the underside of the leaves could be a symptom of an attack by the brown scale insect. As mentioned several times, this parasite infests plants creating colonies, to eliminate it a cotton swab soaked in alcohol will be sufficient or, if the plant is already adult and in pot, it will be washed with soap and water and at the next rinse. In case of persistent infestation proceed with the administration of specific products. Instead, it will be a symptom of an attack of mealy cochineal if you notice spots with a consistency similar to cotton on the underside of the leaves, in this case proceed with the treatment explained for the brown cochineal. In addition to suffering damage caused by nature and our inattention, to parasite infestation, this plant can also be the victim of diseases caused by fungi. White mold, for example, is caused by a fungus, Botrytis, which manifests itself with the appearance of dark spots on all parts of the plant, making them soft and consequently leading to rot. This fungus is very dangerous, in case of infestation proceed immediately with the elimination of the attacked parts and administer a specific product. To prevent the proliferation of this fungus, it will be advisable to never overdo the intake of water during watering and to maintain the right degree of humidity in the environment.



About Aucuba japonica (Japanese Aucuba, Spotted Laurel, Japanese Laurel, Gold-Dust Plant)

Aucuba japonica is a dependable evergreen shrub with attractive glossy green foliage dotted with golden-yellow markings. It is also referred to as Japanese aucuba or spotted laurel - and sometimes referred to by its common misspelling, 'acuba'. Native to Japan, the aucuba, as with many other popular Japanese plants, have a prominent but quiet presence in Pacific Northwest gardens. The variegated leaf reminds me of the tropical Codiaeum croton shrub common in warmer regions. These tips on how to grow and prune aucuba will guide in keeping your shrub healthy and looking great in your garden.

The aucuba is highly adaptable for a sunny location or shady site and almost most garden conditions, including coastal exposure and challenging dry, shaded areas. Perfect for sprucing up a dark corner or an all-green landscape. The aucuba shrub is low maintenance, cold-hardy and easy to care for. It can be used for hedging or as a specimen plant. And looks great planted in an outside planter at the entrance.


Contents

Aucuba japonica was introduced into England in 1783 by Philip Miller's pupil John Graeffer, at first as a plant for a heated greenhouse. It became widely cultivated as the "gold plant" by 19th-century gardeners. The plants being grown were female, and it was a purpose of Robert Fortune's botanizing trip to newly opened Japan in 1861 to locate a male. It was located in the garden of Dr. Hall, resident at Yokohama, and sent to the nursery of Standish & Noble at Bagshot, Surrey. The firm's mother plant was fertilized and displayed, covered with red berries, at Kensington in 1864, creating a sensation that climaxed in 1891 with the statement from the Royal Horticultural Society's secretary, the Rev. W. Wilkes, "You can hardly have too much of it ". [6] A reaction to its ubiquitous presence set in after World War II.

This plant is valued for its ability to thrive in the most difficult of garden environments, dry shade. It also copes with pollution and salt-laden coastal winds. It is often seen as an informal hedge, but may also be grown indoors as a houseplant. [7] Today numerous cultivars are available from garden centers. The most popular cultivar is 'Variegata', with yellow spots on the leaves [8] this is a female clone, a similar male clone being named 'Maculata'. The following cultivars have gained the Royal Horticultural Society's Award of Garden Merit:

  • 'Crotonifolia' [9]
  • 'Golden King' [10]
  • 'Rozannie' - A self-fertile variety not requiring a pollinator, produces deep red berries against solid green, glossy foliage. [11]

  • formlongifolia[12]
  • 'Mr. Goldstrike '- Male plant with leaves heavily speckled in yellow. [13]
  • 'Picturata' - Female plant with yellow foliage fringed with green. [14]
  • 'Petite Jade' - Variety with narrower leaves than other species, slender, and serrated. Solid green, growing to 6 ft. tall (can reach 10 ft. after 20 or more years). [15]
  • 'February Star' - Female plant with narrow leaves and sparse dots of variegation. [16]


How to Grow Aucuba Shrubs

Aucuba plant care is easy if you select a good location. Here is a list of ideal aucuba growing conditions:

  • Shade. Deeper shade means brighter leaf color. Plants tolerate partial shade, but leaves turn black if they get too much sun.
  • Mild temperatures. Japanese aucuba plants survive winters in USDA plant hardiness zones 7b through 10.
  • Well-drained soil. The ideal soil is moist with a high organic content, but the plants tolerate most any soil, including heavy clay, as long as it is well drained.

Plant the shrubs 2 to 3 feet (0.5-1 m.) Apart. They grow slowly, and the area may look sparse for quite a while as they grow to fill their space. The advantage of the slow growth is that the plant rarely needs pruning. Clean up plants as necessary by snipping off broken, dead and diseased foliage and twigs.

Aucuba shrubs have moderate drought tolerance, but they grow best in moist soil. Water often enough to keep the soil moderately moist using cold water. Hot water from a hose that has been left in the sun can encourage disease. Spread a 2- or 3-inch (5-7.5 cm.) Layer of mulch over the roots to help the soil hold moisture and prevent weeds.

Although they are rarely bothered by insects, you may occasionally see scales. Watch for the raised, tan spots on the leaves and stems. Scale insects leave deposits of sticky honeydew that become infested with black sooty mold. You can remove a few scale insects by scraping them off with a fingernail. Treat infestations by spraying the shrub with insecticidal soap or neem oil in early spring before the insects settle down to feed and develop their hard outer shells.

Note: Aucuba is toxic if eaten. Avoid planting aucuba in areas where children play.


Complete genome sequence of aucuba ringspot virus

A new badnavirus, aucuba ringspot virus (AuRV), was identified in plants of Aucuba japonica showing mild mosaic, vein banding, and yellow ringspot symptoms on the leaves. The complete nucleotide sequence of the AuRV genome was determined and found to be 9,092 nt in length, and the virus was found to have a genome organization typical of members of the genus Badnavirus. ORF3 was predicted to encode a polyprotein containing conserved movement protein, coat protein, aspartic protease, reverse transcriptase (RT), and RNase H domains. Phylogenetic analysis suggested that this virus is most closely related to codonopsis vein clearing virus but belongs to a distinct species, based on only 69.6% nucleotide sequence identity within the part of ORF 3 encoding the RT and RNase H domains. The vector of AuRV is unknown, but based on phylogenetic relationships, it is predicted to be a type of aphid.

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Watering The Gold Dust Plant

The aucuba japonica is easy to water. The soil should always remain a bit moist and during the growing season, make sure to water the plant once weekly. In hotter climates, you can water the plant twice a week or every three days to prevent the soil from getting dried out. A well-draining organic soil will ensure the right amount of moisture is maintained for the roots without getting too soggy.

You can add the gold dust plant to your indoor garden or even your patio with a dramatic effect. Use containers that have plenty of drain holes in the bottom to prevent root rot from stagnant water.

On the topic of watering, it is best to water this plant by pouring tepid water directly on the soil. Watering the top of the leaves can encourage fungal growth such as leaf spot. Too much water can lead to root rot and the eventual death of the plant. Along with well-draining soil, make sure there are plenty of drainage holes in the bottom of the pot.

A mature gold dust plant can grow as tall as a house and live for up to two decades. They love healthy soil and shaded spaces, so consider planting them on the side of your home that doesn't face the sun. In soil that is well-drained the plant will thrive without becoming dehydrated, but make sure that it is watered often enough that the soil remains slightly moist.


Picturata

Aucuba japonica 'picturata'

Description

An excellent accent for shady situations. Broad-leaved evergreen shrub valued for the showy dark green leaves with bright golden yellow centers. Bold upright stems. Well-drained soil enriched with organic matter.

Growth

Slow growth rate to height of 4-6 'and width of 4-5'

Light

Borders containers houseplant woodland garden specimen


Video: AUCUBA: Aucuba japonica


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