Tag Archives: aucuba

Aucuba collections at the JC Raulston Arboretum

A selection of almost 80 Aucuba from the JC Raulston Arboretum to be displayed at the NCNLA Winter Trade Show.

A selection of almost 80 Aucuba from the JC Raulston Arboretum to be displayed at the NCNLA Winter Trade Show.

I like to think of Aucuba japonica as the Rodney Dangerfield of plants.  Despite a long history of success in the garden, it still just gets no respect.  In fact, at a recent international meeting when I mentioned that the JC Raulston Arboretum was developing a significant collection a woman from the UK good-naturedly called it a parking lot plant while folks from various other countries nodded in agreement.  Since only the toughest of plants can grow around parking lots I consider that as a mark in favor of the plant and not a knock against it.

Aucuba chlorescens has conspicuously bullate foliage and is found in northern Vietnam and Yunnan.

Aucuba chlorescens has conspicuously bullate foliage and is found in northern Vietnam and Yunnan.

Aucuba has traditionally been placed within the dogwood (Cornaceae) family but in a rare show of respect has also been occasionally placed in its own family, Aucubaceae.  Most recent treatments including the Angiosperm Phylogeny Working Group have grouped Aucuba with Garrya in the Garryaceae family.  Aucuba is a group of about 10 or more species although the genus is still in some flux and there is likely several as yet unnamed species.  All the members of the genus are evergreen trees or shrubs with separate male and female plants.  Both sexes are generally necessary for fruit production on the females but there are a few selections of Aucuba japonica which will often fruit without a male nearby.  Interestingly, there is a very long period – often several weeks – between pollination and actual fertilization in the genus.

Showy fruit on a green leaf female aucuba.

Showy fruit on a green leaf female aucuba.

John Graeffer first intoduced the Japanese aucuba (A. japonica) to the west in 1783.  It represents one of the rare occasions when a variegated form of the species is introduced before the non-variegated type.  His introduction, ‘Variegata’, was the typical spotted “gold dust” plant that is still so common in the south.  Although the introduction was a female, it was not until a male was introduced over half a century later that the ornamental value of the fruit was known in Europe.

Male flowers are easily identifiable on Aucuba japonica with their 4 yellow stamens.

Male flowers are easily identifiable on Aucuba japonica with their 4 yellow stamens.

W.J. Bean in his excellent Trees and Shrubs Hardy in the British Isles (2nd ed.) in 1916 has nothing but positive things to say about Aucuba japonica and noted that it was valuable for its tolerance to the dry shade found under lindens, horsechestnuts, and beech.  By the 1976 revised 8th edition of the classic reference book it was noted that Japanese aucuba was also quite tolerant of urban conditions including smoke and other air pollution but the intervening 60 years between these 2 editions necessitated the comment “Today the aucubas… are out of favor, but the pendulum has swung too far.”  The pendulum has never really swung back though and while many thousands of aucuba are produced and sold each year they are still considered a somewhat plebian plant perhaps simply for growing so easily.

Aucuba japonica makes an evergreen shrub to about 8’ tall if left unchecked.  In the wild it can be found both as a solid green-leaf plant or speckled with gold.  The glossy thick-textured leaves are held opposite on the stems and leave conspicuous leaf scars after they fall.  The upright rounded form is made up of a many erect, often little branched stems which are typically quite thick, smooth, and bright green.  Male plants bear terminal spikes of burgundy flowers in early spring which are quite attractive on close examination but won’t stop a car driving by.  Female flowers are somewhat less showy and are carried in the leaf axils.  The bright red fruits ripen in the fall and stay showy often through the winter and into spring.

An impressive collection of aucuba in Japan at Garden Kinosata

An impressive collection of aucuba in Japan at Garden Kinosata

The JCRA has begun accumulating aucuba in earnest and now has about 95 selections and species.  There are likely duplicates since many Japanese selections have been re-named over the years and much confusion exists in the literature.  We have propagated most of our collection and plan to plant them out together in order to compare them side by side for variegation, growth habit, and fruiting show.  Over time, we hope to clear up some of the confusion that currently exists and select the best of the bunch for promotion.

Aucuba, especially A. japonica, are easy to grow and as noted tolerate dry shade, pollution, and significant root competition from larger trees.  Female selections will fruit best if planted in a relatively bright spot with male forms nearby.  They will grow in full sun situations but will often have a somewhat washed-out appearance and are really at their best with some protection from harsh afternoon sun.  Aucuba are easy to propagate from cuttings at almost any time of year from softwood or hardwood cuttings and will form thick vigorous roots often within a week of being stuck.

There is a canker that can affect aucuba especially in overly wet locations.  It girdles the stems and will turn entire branches and occasionally the whole plant black.  When this dieback is first noticed, all affected parts should be pruned back well into healthy wood.  The pruners used should be sterilized with a 10% bleach solution after each cut to avoid spreading the disease.  Severely affected plants should be removed, bagged, and thrown away to prevent becoming a source for infection of other aucuba nearby.

A few selections of Japanese aucuba that have impressed us in recent years include:

 ‘Hosoba Hoshifu’ – A form with yellow spotted, narrow leaves.  This selection has exceptionally glossy foliage and bright red fruits.  In a group that often looks interchangeable, this form really stands out.P1130071

 ‘Ooba Nakafu’ – This form has huge leaves with a bright gold center.  In heavy shade, the gold fades to a pale green but is still quite attractive.  We expect this to become a fairly large plant.

Aucuba japonica 'Ooba Nakafu' 001 Hawksridge 2-13-08

‘Hime Kikufurin’ – This form has a bright gold margin to the leaf that is much deeper in color than some of the older selections.  It should ultimately be somewhat smaller than the similar ‘Limbata’.  So far it has held this color quite well even in deep shade.DSC_4739

 

‘Natsu-no-kumo’ – This is a patented selection discovered by the Japanese plantsman Seiju Yamaguchi.  The new growth emerges pure white in spring before turning green.  A full size plant is quite a sight in the garden.DSC_3452

 ‘Daisuke’s Tiger’ – This is mostly gold around the margins and tips and spotted with green while the green centers are speckled with gold.  Quite a distinctive plant discovered by Daisuke Muramatsu in Japan and introduced by Asiatica Nursery.DSC_6380

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UK Travel 2013 – Part 3, National Collections and the National Gardens Scheme

A portion of Linda Eggins' main aucuba collection.

A portion of Linda Eggins’ main aucuba collection.

7/23/2013

The JC Raulston Arboretum has been slowly creating one of the most significant collections of Aucuba in the US (about 75 taxa currently) with the thought of possibly becoming a national collection via the North American Plant Collections Consortium (NAPCC).  We already hold a NAPCC Cercis (redbud) collection and are part of a multi-institution magnolia collection.  To that end, I decided to visit the UK’s national aucuba collection held by Linda Eggins in the Midlands of England.

The UK’s National Collection Scheme is run by Plant Heritage (National Counsel for the Conservation of Plants and Gardens) whose mission is to:

…conserve, grow, propagate, document and make available the amazing resource of cultivated plants that exists in the UK.

Unlike the NAPCC program in the US which relies on public gardens with high curatorial standards and a proven track record, the UK’s program utilizes both public gardens and individuals.  Linda Eggins’ aucuba collection is an example of why working with individual gardeners can be so beneficial.

Not an aucuba to be found in this portion of Linda's garden.

Not an aucuba to be found in this portion of Linda’s garden.

Linda has an excellent collection of Aucuba japonica with a focus on some of the older cultivars although new ones exist in her garden as well.  She has undertaken a trip to Japan to see aucuba in the wild and in gardens and has done extensive research on the earliest introductions and catalog listings of aucubas from the late 1700’s to see if current cultivars can be matched to the old descriptions.

As we walked through her lovely garden looking at her aucuba and the rest of the garden which she crafted with her late husband, it was gratifying to see that she took her part in the National Garden scheme so seriously.  With a few cuttings of older selections to match up with ours and some newer ones – I’m very excited about ‘February Star’, a Great Dixter cultivar and Linda’s own ‘Clent Wortley Hall’ – we retired to the house to look into the research she had compiled.  I’m looking forward to potential future collaborations.

Aucuba japonica 'February Star', a selection made at Great Dixter.

Aucuba japonica ‘February Star’, a selection made at Great Dixter.

Another UK wide program is the National Gardens Scheme (NGS).  This program encourages people to open their gardens on specific days with the proceeds (generally 5 pounds per garden) going to support a range of charities.  John Grimshaw took me to visit the open garden of Matthew Pottage in Withernsea on the east coast of England near Hull.  Matthew is a young phenom who was hired a couple of years ago at age 25 to be the garden manager at RHS Wisley, one of the premier gardens in the world.

Matthew's back garden with several members of the public taking advantage of his open garden day.

Matthew’s back garden with several members of the public taking advantage of his open garden day.

Technically the garden is at his parent’s house but his mother assured me that the garden was all Matthew’s since he did not have his own yard to garden.  The Wisley flair for combining unusual plants in beautiful ways and creating lovely palettes of color was in ample evidence.  The small suburban garden had its own tiny walled garden, a wild garden, vegetable garden, shade and water gardens as well as a more typical English cottage garden with climbing roses and masses of color.  There was even a touch of the formal to the garden.

The brilliant use of color is one of the hallmarks of Mathew's garden.

The brilliant use of color is one of the hallmarks of Mathew’s garden.

The sky is definitely the limit for Matthew and I’m hoping we can convince him to come visit us for a lecture or workshop in the not too distant future.

Matthew educating one of the many visitors to his garden.

Matthew educating one of the many visitors to his garden.

Follow me at @jcramark because life is too short for boring plants.

Lush borders and winding paths make the garden seem much larger than its actual size.

Lush borders and winding paths make the garden seem much larger than its actual size.

Woodies, herbaceous perennials, and tropicals are expertly combined.

Woodies, herbaceous perennials, and tropicals are expertly combined.

The touch of formality near the house offsets the exuberance of the rest of the garden.

The touch of formality near the house offsets the exuberance of the rest of the garden.

Even the hedges are delightful.

Even the hedges are delightful.

 

Check out all the happenings at http://www.ncsu.edu/jcraulstonarboretum

Pic of the Day – Aucuba japonica ‘Hosoba Hoshifu’

Aucuba are great for dry shade.

Aucuba are great for dry shade.

The JC Raulston Arboretum holds a significant collection of Aucuba, over 70 taxa at this point and growing steadily.  This form, ‘Hosoba Hoshifu’ is quickly becoming a favorite.  Long, narrow leaves are heavily serrated and covered in bright gold spots.  The lanceolate foliage gives a distinctive look to this speckled aucuba.  Spikes of small maroon flowers give rise to large, bright red fruits if there are male forms around to pollinate it.  ‘Hosoba Hoshifu’ is a slightly more compact form but will slowly grow to near 6′ over time.  Aucuba are great plants for growing in dry shade where they will tolerate the difficult conditions well once established and the variegation will brighten the gloom.

The narrow foliage is distinct on this selection.

The narrow foliage is distinct on this selection.