Minggu, 20 April 2014

Plant of the Month (April) : California coffeeberry - Frangula californica (Rhamnus californica)




California coffeeberry (Frangula californica): two year old plant in Mother Nature's Backyard






Most
gardens, even those of modest size, need a shrub or two; and California natives
can be a good choice.  Many are
water-wise and most have interesting flowers, fruit or foliage.  Of importance to busy gardeners, many are also
quite easy to maintain (once they’ve been coaxed to an attractive shape in
adolescence).  Gardens in our area are
continually enriched by their inclusion of native shrubs.






One
point to be aware of is size.  Native
shrubs come in all sizes – from small to very large.  Before choosing a shrub, seriously consider
its mature size. Yes, it really will
get that big – maybe even a little bigger. 
And it will likely be difficult to keep it smaller.   Choose
the right size shrub for your space; then you and your shrub will be happy for
years to come.






California
coffeeberry (
Frangula
californica
; formerly Rhamnus
californica)
is one of the better native shrubs for the home garden.  The species itself is large – to 8-12 ft tall
and about as wide under favorable conditions. 
This is big, although it can
be hedge-pruned to somewhat smaller if you’re willing to do the work.   Fortunately,
there are several smaller cultivars (discussed below) which may be just right
for your space and garden design.






Coffeeberries are members of the Buckthorn family (Rhamnaceae) which includes the
Ceanothus, the Redberries (genus Rhamnus)
and other plants more common to the sub-tropics and tropics.  The plants are known for their flowers, which
grow in parts of 5 (occasionally 4) and have a distinctive star-like shape. Many
of the  California species are used as
garden shrubs.






California coffeeberry is native from southern
Oregon to Baja California, Mexico.  It grows
in the Santa Monica and San Gabriel Mountains of Los Angeles County, and even
occurs in the foothills of Nevada and Arizona. 
It’s most often found at lower elevations (below about 3500 ft.) but extends
to 5000 ft in some locations.  In the
northern parts of its range, Coffeeberry usually grows on drier slopes.  In warmer regions like S. California, look
for it on north-facing slopes and in shady canyons, often near streams. 






Coffeeberries grow in areas that experience
periodic fires.  They have specially adapted
root-crowns that contain dormant buds. 
These buds sprout after a fire (or after the plant is coppiced (cut down
nearly to the ground) allowing them to recover quickly after a fire.   The post-burn growth rate can be amazingly
fast!






There are several subspecies of California
coffeeberry, including three from Los Angeles County.  The more common Frangula californica ssp. californica  has a statewide distribution in western
California (including the northern California coast) and is the most common
type sold in native plant nurseries. It’s well-loved by gardeners for its
shiny, evergreen, medium-green foliage.  Subspecies
californica grows in a number of plant
communities including
Chaparral,
Coastal Sage Scrub, Coastal Strand, Mixed-evergreen Forest, Northern Coastal
Sage Scrub, Redwood Forest and Central Oak Woodland.






Frangula californica ssp. tomentella  is found occasionally in the Santa Monica,
San Gabriel and Tehachipi mountains as well as in California’s Central/Northern
coastal foothills and those of the western Sierras.   The leaf color in this subspecies is an  attractive, matt (not glossy) blue-green; the
leaves are usually more elongated and the undersides are densely hairy.   This
subspecies is often available in nurseries, though it’s less common than subspecies
californica.






The
less widely distributed
Frangula
californica
ssp. cuspidata
grows in desert chaparral, desert scrub and woodlands of the eastern Sierra,
Tehachapi, San Jacinto and Transverse mountain ranges of Central and Southern
California.    This desert-adapted
species also has leaves with short dense hairs (primarily on the underside) and
a gray-green appearance.  It is occasionally
offered by local native plant nurseries, particularly those that cater to
clients from desert areas.








California coffeeberry (Frangula californica) at one and two years after planting as a 1-gallon plant









In
this posting we’ll focus on
Frangula
californica
ssp. californica,
as it is routinely available at native plant nurseries and we have two of
them in our mixed hedgerow in Mother Nature’s Backyard.
 California coffeeberry is a
large shrub or occasionally a small tree.   Under favorable conditions it can grow fairly
quickly to 4-6 ft tall and wide, then more slowly to 8-12 ft.  The photo above shows one of our Coffeeberries
at one and two years after planting as a one-gallon plant.   As can
be seen, it has already developed a nice, rounded shape with very little
pruning.






The leaves of Frangula
californica
ssp. californica are
evergreen, simple and pleasant to the eye. 
Leaves are 1 ½ to 4 inches long, alternate, and shiny above, with edges
that may be straight or slightly serrated. 
The leaf margins roll under slightly when the plant is drought stressed.
 As seen in the photo below, new leaves
are a very light green; older leaves become darker.   This shrub makes a nice green backdrop for
colorful flowers and plants with light colored foliage. 















Coffeeberry is many-branched, forming a dense
rounded form, particularly when clipped occasionally (by wildlife or
gardeners).  The young bark is usually
red-brown, becoming gray with age.  The
dense growth habit makes it an excellent candidate for a hedge/hedgerow shrub
or foundation planting. Plants reach their maximum size in 15-20 years.  In the wilds, plants are often long-lived –
to at least several hundred years old.


 














Coffeeberries bloom in spring over much of their
range.  In our area, they bloom as early
as March and can continue into May.   The
flowers are inconspicuous.  In fact the
first thing you may notice is a cloud of pollinators swarming around them!  Coffeeberry flowers are perfect (contain both
male and female organs), small (~ ¼ inch) and pale yellow-green to white (see
photo above).  The flowers are in parts of
5, typical for the Buckthorn family.






Coffeeberries, like the Ceanothus, are insect
pollinated.  They attract a great number
and range of pollinators including European honey bees, native bees (usually
the smaller species), pollinator flies and others.   The pollinators are a joy to watch – and the
show goes on for 3-4 weeks.  In our
experience, the pollinators are so focused on the flowers they pretty much
ignore passing – and even photo snapping - humans. 















While Coffeeberry flowers are inconspicuous, their
fruits are anything but!  Coffeeberries
produce rounded, berry-like drupes (fleshy fruits with a stony pit) that are ¼ to
½ inch in diameter.  Fruits are green in
late spring, turning to yellow, red and almost black through summer/fall as
they ripen.  Fruits of several colors at
the same time are common, making for quite a show!  Fruits contain two hard-coated seeds which
resemble coffee beans (hence the common name). 
  Contrary to their appearance, they don’t make a great coffee substitute.






Although occasionally eaten by Native Californians,
the fruits have strong laxative properties are not really edible for humans.   But birds - even animals - eat them with
gusto.  Birds are the primary seed
dispersers and they do a good job; in the wild, few seedlings develop near
parent plants.  Robins, Finches, Towhees,
Mockingbirds and Jays all eat the fruit.  In fact, one of the reasons we included
Coffeeberry in our hedgerow was to attract these bird species. Plants begin
producing at 2-3 years of age, so you’ll have fruits within several years of
planting. 






Coffeeberry is quite adaptable to garden
conditions.   It thrives in most local
soils, from sandy to clay, as long as it’s watered properly.  It can be grown in full sun to part-shade and
is fairly drought tolerant once established.   Coffeeberries, including the cultivars, are
good choices when a part-shade tolerant shrub or groundcover is needed; for
example under tall trees or to the east or north of large trees or walls. In
our warmer S. California gardens, Coffeeberry is often at its best under such
conditions.








Mature California coffeeberry (Frangula californica): Rancho Santa Ana Botanic Garden, Claremont, California









In our area, Coffeeberries benefit from occasional
deep watering during summer (Water Zone 2 is probably best; see http://mother-natures-backyard.blogspot.com/2012/04/water-wise-gardening-tip-save-water.html
).  Be sure that the soil is dry at a
depth of 4 inches before watering – and water during a cooler spell, in early
morning or late in the day.  
Coffeeberries like an organic mulch (see 
http://mother-natures-backyard.blogspot.com/2012/07/understanding-mulches_23.html
for more on mulches). 






Coffeeberries have a nice natural shape and appear
pruned even without any pruning.  They
can be shaped for hedging – just a light trimming during the growing season to
create a semi-formal hedge.  The more
open cultivars – like ‘Bonita Linda’ – can even be trimmed up to make an
interesting small tree.  Of course the most
common use for Coffeeberry is as a background or accent shrub in water-wise
gardens.  It is a good alternative to commonly
used non-native shrubs like
Carissa, Cotoneaster,
Elaeagnus
angustifolia

(Russian olive), Myoporum laetum (ngaio tree);
 Ligustrum,
Myoporum, Oleander, Photinia,
Pittosporum
, Raphiolepis and
Xylosma.















Coffeeberries can
be combined with other native shrubs that share similar water requirements.  Some good companion shrubs/trees include
Chaparral whitethorn (Ceanothus leucodermis), Toyon (Heteromeles arbutifolia), Sourberry (Rhus trilobata) and the Redberries (Rhamnus crocea).  The more drought-tolerant cultivars – and the
species – can even be grown under native oaks like coast live oak (Quercus agrifolia).


 













Several excellent cultivars are available.  The smallest of these is Rhamnus
californica

‘Little Sur’, a very dense, compact
(dwarf)
shrub
that grows only 3-4 ft tall and wide. 
This is probably the best choice for smaller hedges and for
containers.   It is particularly well suited to coastal
areas.  Cultivars ‘Seaview’ and ‘Seaview
Improved’ are very low-growing (to about 2 ft.) and spreading.  They make an interesting groundcover shrub.


 








 






Several cultivars are only slightly smaller than
the species – but enough so to make them good garden candidates. Rhamnus
californica

'Eve Case'
is widely available in California
native plant nurseries. 
 ‘Eve Case’ grows more slowly than the species,
becoming 6-8 ft. tall at maturity, but more commonly about 6 ft. tall and
wide.  It is very drought tolerant, does
well in coastal gardens and is probably the most commonly garden Coffeeberry.  It has all the good attributes of the species
and has been used in gardens since the 1970’s.






Rhamnus
californica

'Leatherleaf'
is a 6-8 ft cultivar with
very dark green leaves and a mounded growth habit, becoming broader with age. It
takes a bit more water and likes a little shade in our area.  
Rhamnus
californica

'Mound San Bruno'
also has a mounded
shape.  It grows to 4-6 ft tall and 8-15
ft. wide; it makes a good tall groundcover under trees and on north-facing
slopes.  Both of these cultivars are less
frequently available in Southern California nurseries.






Rhamnus
californica

'Bonita Linda'
is a large cultivar (8-10
ft tall and wide) with a more open growth habit and gray-green foliage.  It is used like the species – for large
background shrub or as a screen or hedge. 
It is probably the best candidate for pruning up into a small tree.   It
does well in S. California gardens and can be watered several times a month in
summer if desired.  It is commonly
available in S. California native plant nurseries.






Native Californians used a preparation from the
bark of California coffeeberry as a laxative. 
It is very powerful and requires careful preparation and use.   While not well known as a dye plant, the
foliage can be used to make a golden dye, which is more intense when plant materials
are collected in fall. 






In summary, California coffeeberry is a wonderful
shrub with great habitat potential.  It
looks like a garden shrub, is evergreen and water-wise.  In addition to the species, there are
cultivars that range in size from small to large.   We hope you’re inspired to consider this
wonderful native shrub in your garden. 
And do take a look at ours when you come to the garden.






 






For a
gardening information sheet see:
http://www.slideshare.net/cvadheim/frangula-californica


















Coffeeberry in MNBY - 2014 (2 years old)

 




Coffeeberry in MNBY - 2016 (4 years old)




 


Five years growth in Mother Nature's Backyard

California coffeeberry - Frangula californica










 






We
welcome your comments (below).  You can
also send your questions to:
mothernaturesbackyard10@gmail.com




 

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