I walk by a home with some beautiful landscaping in the front, including lots of aucuba. The only way I have seen this shrub is with variegated leaves. Its colors really do create a splash in the landscape. I used to have some of it in my front yard Longview in East Texas. I liked my last house in Longview because I could mow the front yard in 30 minutes. The back yard was larger and took much longer to mow, but it was easier to let it grow unabated because the only people who saw it were me and the neighbors on either side. At any rate, the yellow-spotted leaves of the aucuba stood out in my front yard landscaping. Let’s find out more about it.
According to Wikipedia, aucuba is a genus of three to ten species of flowering plants, now placed in the family Garryaceae, although formerly classified in the Aucubaceae or Cornaceae.
Aucuba species are native to eastern Asia, from the eastern Himalayas east to China, Korea and Japan. The name is a latinization of Japanese Aokiba. They are evergreen shrubs or small trees 2–13 meters tall, similar in appearance to the laurels of the genus Laurus, having glossy, leathery leaves, and are among the shrubs that are mistakenly called laurels in gardens.
The leaves are opposite, broad lanceolate, 8–25 cm long and 2–7 cm broad, with a few large teeth on the margin near the apex of the leaf. Aucubas are dioecious, having separate male and female plants. Flowers are small, 4–8 mm diameter, each with four purplish-brown petals; 10-30 are in loose cymes. Fruit are red drupes about 1 cm in diameter.
Cultivation
Sowing Seeds. Clean the outer fleshy pulp from the seeds, which may be sown as soon as the fruit ripens in the autumn. Can be planted in pots. Soil should be sandy and around 50-55 degrees Fahrenheit.
Cuttings. Perhaps the best way to propagate is by taking cuttings in the spring. Cuttings will grow roots in a few weeks.
Where to Plant. Aucubas may be planted outside but starting in zone 6 plants should be kept in sheltered locations. Does well beneath trees as it thrives in shade and dry areas. No special feeding is required, and plants tend to grow into desirable bush shapes with very little pruning. For the best crop of drupes, plant a male plant among every six female plants.
Some species
Aucuba chinensis
Aucuba chinensis is a shrub or small tree, native to southern China, Taiwan, Burma and northern Vietnam. Typically, it grows to 6 meters tall, though it can be larger. The leaves are thick, dark green above and light green below, sometimes with teeth along the margins.
Aucuba japonica
Aucuba japonica, commonly called spotted laurel, Japanese laurel, Japanese aucuba or gold dust plant — in the U.S., is a shrub 3.3–16.4 feet tall, native to rich forest soils of moist valleys and thickets, growing by streams and near shaded moist rocks in China, Korea and Japan. This is the species of Aucuba commonly seen in gardens — often in variegated form. The leaves are opposite, broad lanceolate, 2.0–3.1 inches long and 2–5 cm (0.79–1.97 in) wide. Aucuba japonica are dioecious. The flowers are small, 0.16–0.31 inches in diameter, each with four purplish-brown petals; they are produced in clusters of 10-30 in a loose cyme. The fruit is a red drupe approximately 0.39 inches in diameter, which is avoided by birds.
The variegation, considered by some to be an attractive property, is caused by 'Aucuba bacilliform,' a putative species of virus in the genus Badnavirus.
Cultivation and uses
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 of 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". 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. Today numerous cultivars are available from garden centers. The most popular cultivar is 'Variegata,' with yellow spots on the leaves; 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'
- 'Golden King'
- 'Rozannie' – A self-fertile variety not requiring a pollinator, produces deep red berries against solid green, glossy foliage.
Other cultivars include:
- forma longifolia.
- 'Mr. Gold Strike' – Male plant with leaves heavily speckled in yellow.
- 'Picturata' – Female plant with yellow foliage fringed with green.
- 'Petite Jade' – Variety with narrower leaves than other species, slender, and serrated. Solid green, growing to 6 feet tall, can reach 10 feet after 20 or more years.
'February Star' – Female plant with narrow leaves and sparse dots of variegation.
Aucuba planting and care advice
According to the article “How to Plant, Fertilize, Prune & Water Aucuba Plants in the Ground or Containers” in Wilson Bros Gardens Advice Blog at https://wilsonbrosgardens.com/planting-and-caring-for-aucuba.html, aucuba, commonly called Japanese laurel by some, are prized for their bold foliage and adaptability to shade, dry soil, pollution and coastal conditions. When planted right and in the right spot, they are exceptionally easy to grow and care for. Their tropical-looking evergreen leaves make aucuba plants a perfect choice for bringing a flare of the tropics to your landscape. You can also grow them indoors as a houseplant.
Soil preferences in the landscape
Aucuba adapts to a wide variety of soil types provided the soil is well-drained. It prefers growing in a well-drained soil rich in organic matter. As with so many other types of ornamental plants, constantly soggy or wet soil can cause root rot and other harmful plant diseases. So, make sure to plant them in a well-drained site. Heavy clay and other compacted soils should be amended with organic matter to improve drainage.
Soil preferences in pots & other containers
Aucuba grows best in a very well-drained damp to somewhat dry soil. Therefore, when planting and growing them in containers, use a premium potting mix or potting soil, or a 50/50 mix of the two, in a container that has a drainage hole(s).
How to test soil drainage
If you are uncertain about soil drainage in the area you intend to plant, it's well worth taking the time to test the drainage before planting. To test soil drainage, dig a hole 12" wide by 12" deep in the planting area. Fill the hole with water and let it drain. Then, after it drains, fill it with water again, but this time clock how long it takes to drain. In well-drained soil the water level will go down at a rate of about 1 inch an hour. A faster rate, such as in loose, sandy soil, may signal potentially dry site conditions. A slower rate indicates poor draining soil and is a caution you need to improve drainage, plant in a raised mound or bed or look for plants that are more tolerant of wet or boggy conditions.
Soil pH
Aucuba tolerates a wide range of soil pH between 4.5 to 8.0 on the pH scale. That said, it grows best in a moderately acid to neutral soil ranging between 6.0 to 7.0 on the pH scale. Most average garden soils fall between a pH range of 6.0 to 7.0.
Soil pH is a measurement of the alkalinity or acidity of soil and is measured on a scale of 1-14, with 7 as the neutral mark. Any measurement below 7 indicates acid soil conditions, and anything above 7 indicates alkaline. If you're unsure about the pH of your soil and whether or not it's suitable for growing aucuba, it's a good idea to test the soil pH in the planting area. You can quickly test soil pH with an inexpensive soil pH tester probe. To raise the pH or make it more alkaline you can add pelletized limestone to the soil. To lower the pH or make it more acid you can apply soil sulfur, aluminum sulfate or chelated iron. Adding organic compost to the soil or using compost as mulch can also help to increase acidity and maintain acid soil conditions.
Light preferences
Aucuba grow and look their best in full shade to part shade. Morning sun is okay but direct afternoon sun can and often will scald leaves.
Planting aucuba in the ground
1. Start by digging your planting hole at least two to three times as wide and only as deep as the height of the rootball of your plant. The wider the hole the better. Place native soil removed from planting hole around the perimeter of the hole, in a wheelbarrow or on a tarp.
2. Depending on the type, fertility and porosity of the soil in the planting area you might need to mix in a soil amendment to the native soil removed from the planting hole. When planting in dense clay or other poor draining soils it is beneficial to thoroughly mix in some good organic matter such as bagged topsoil and/or a good planting mix at a 25-50% ratio with the soil removed from the planting hole. When planting in very sandy or quick-draining soil, mixing in some topsoil, peat moss and/or compost will help to retain moisture in the soil.
3. Remove your aucuba plant from the nursery pot. Be careful not to damage the plant when removing it from its pot. If the rootball is stuck in the pot, cut the container away. After removing the plant from the container, use your fingers to carefully loosen some feeder roots around the surface of the rootball.
4. If you are planting in well-drained soil, which is a must for aucuba plants, set your plant in the planting hole so that the top edge of the rootball is at or just slightly above ground level to allow for settling. If your soil is moderately drained — meaning it drains slowly after rain — the top of the root ball should be 2 inches or more above ground level, as shown in the illustration above. If necessary, add some backfill soil mixture to the bottom of the hole to achieve proper planting height.
Note: If the soil is poorly drained i.e., constantly soggy or wet, take measures to improve drainage or select a different plant species tolerant of wet soils.
5. After setting your aucuba in the planting hole, use one hand to hold the plant straight and your other hand to begin back-filling your soil mixture around the root ball, tamping as you go to remove air pockets. When you have filled the hole to the halfway point you can soak the soil. Then continue back-filling to the top edge of the root ball. If you are planting the root ball higher than ground level, as shown in the illustration, taper your soil mixture gradually from the top edge of the root ball to the ground level. To avoid suffocating your plant, avoid placing any soil on top of the root ball.
7. Deeply water the planting area, including the rootball, to a depth equal to the height of the rootball. For an extra boost, you can water your newly planted aucuba with a solution of root stimulator, which stimulates early root formation and stronger root development, reduces plant shock and promotes greener, more vigorous plants.
8. To conserve moisture and suppress weed growth, apply a 1 to 2" layer of cured, shredded or chipped wood mulch or pine straw around the planting area. Avoid using freshly chipped wood for mulch until it has cured in a pile for at least six months; a year is better. Avoid placing or piling mulch directly against the base of your plant as this could cause the bark to rot.
Fertilization
To maintain good health and appearance, Aucuba will appreciate fertilizer. Feed Aucuba plants in late winter or early spring before new growth begins to emerge.
In the landscape fertilize aucuba growing in the ground at rates recommended on the product label with a slow-release shrub & tree type fertilizer that contains iron and/or sulfur for deep greening. Alternatively, you can feed plants with an organic plant food. If plants look like they could use a second fertilization, you can feed them again in mid to late summer. To avoid frost damage to new growth stimulated by fertilization, cease feeding plants two months prior to the first frost date in your area.
Note: If the foliage of your aucuba plants develop chlorosis or fading of foliage, this could be an indicator of a high soil pH or alkaline soil. To acidify soil and for deep greening, simply apply iron or soil sulfur at rates suggested on the product label.
Shrubs feed themselves from their root system. The feeder roots of established shrubs are found at and beyond the outside perimeter of the branch system, what many professionals call the "drip line." Therefore, this is where most of the fertilizer should be spread.
How far outside the drip line you spread fertilizer will depend on the age and size of the shrub. As a general rule, spread the fertilizer under the plant and 3-4 inches beyond the drip line for each 12 inches of shrub height. For example, if a shrub is two feet tall spread the fertilizer about 6 to 8 inches beyond the drip line.
In pots or containers feed as directed on product label with a slow-release or water-soluble plant food listed for use in containers.
How to water aucuba
Young plants will need some water to develop a root system, but not too much. When established, aucuba are exceptionally drought-tolerant plants. Here's some tips for watering them.
Immediately after planting, deep-soak the soil in the planting area to a depth equal to the height of the plant’s root ball. For an extra boost, to stimulate early root formation and stronger root development, you can also water your newly planted aucuba with a solution of root stimulator, which reduces transplant shock and promotes greener, more vigorous plants. When planted during the winter, dormant season plants will require less water. So, be extra careful not to overwater during winter!
In average garden soil you should not have to water your newly planted aucuba every day. More often than not, this causes soggy soil conditions that can lead to root rot and other harmful plant diseases. In the absence of sufficient rainfall, water only as needed to keep the rootball and surrounding soil damp to moist.
Keep in mind that deep soaking less frequently and allowing the soil to dry out somewhat before watering again is much better than splashing just a little water on the plants every day.
During prolonged periods of drought aucuba will appreciate some water. If during a drought you see leaves wilting or falling from the plant or new branch tips are drooping, this could be a sign your plants could use a good, deep soaking.
Note: When watering with an automated irrigation system, it's best to set your timer to water during the early morning hours and not in the late evening or at night, which can lead to the onset of fungus and other foliage diseases. During the first few weeks after planting, check soil moisture often and adjust irrigation time, if necessary to keep the soil moist, not wet.
Pruning aucuba plants
Aucuba do not require pruning but respond very well to almost any amount of it. Older, healthy plants that have outgrown the space they were intended to fill can be pruned back almost to the ground and will usually grow back.
Pruning to shape or remove stray or damaged branches can be performed any time from early spring to late summer. If at any time a branch dies, remove it immediately by cutting at a point several inches below the dead part.
Heavy pruning, to substantially reduce the size of the shrub, should be performed in late winter or early spring before new growth begins to emerge. Cease pruning two months prior to the average first-frost date in your area.
Pruning on young plants may only require a thumb and forefinger. Pinching off tip growth will help promote bushiness.
For general shaping and to keep your aucuba plant tidy, you can use a sharp pair of bypass hand pruners to prune branches that have outgrown the rest of the shrub and are spoiling the shape of the plant. Make your cuts an inch or two above a leaf. To reduce the height of the shrub, prune the growth to the next growing point for best results.
Note: Hedge trimmers are not recommended for pruning aucuba as their blades cut into the large leaves leaving an unsightly appearance.
If you have an Aucuba plant that has outgrown the space it was intended to fill or is looking old and tired, a hard or rejuvenation pruning may be in order. This type of pruning is performed in late winter, when the plant is dormant and before new spring growth begins to emerge.
Rejuvenation pruning is a drastic form of pruning in which the entire shrub is cut back to a height of 6 to 12 inches above the ground. After cutting back a healthy shrub it will usually start growing new branches and foliage in spring.
Note: While aucuba plants typically respond well to rejuvenation pruning, there are no guarantees your plants will survive it. That said, if your plants are dying from disease or old age what do you have to lose? Even sickly plants sometimes are rejuvenated by this drastic type of pruning.
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