PBS TOW
Peonies on the West Coast Part 2 by James W. Waddick
Chinese Peonies
There is a single species, P. lactiflora, that is the primary
garden peony around the world. Chinese selections have been grown for
centuries. Chinese and European selections have produced hundreds of
available cultivars. These make up the classic large double-flowered red,
pink or white flowers that are still the mainstay of the peony cut-flower
market. They are northern plants and have specific growth requirements that
have shaped the entire understanding of most gardeners.
They are not always the best garden plants; their large blooms
fall over due to weak stems or in the first wind or rain. Plants are often
big and too unkempt to grow in the perennial border, but are often put
aside as an herbaceous 'hedge' or for foundations. Native to northeast
China, they do not grow well in mid-temperate or milder climates. They need
an extended cold dormancy for successful bloom, but can be cultivated well
into Canada.
All other herbaceous peonies
After all the above have been considered, there are another 20 or
so peony species that are quite variable and offer a range of interesting
possibilities. Some of the more distinctive 'types' are: the fern leaf
peony (P. tenuifolia) with leaves finely dissected into as many as 200
needle-like segments per leaf; the Himalayan P. emodi which gets over four
feet tall with large white Anemonelike flowers; P. mlokosowitschii, an
unflowing name for the only yellow-flowered herbaceous peony from the
Caucus Mountains; and the native European P. officinalis long a staple of
herbal medicines and increasingly endangered due to growing human
populations and environmental decline. These and other species have been
hybridized with each other and P. lactiflora to produce a range of garden
hybrids in a wider range of flower colors, stature and form than found in
nature.
Peonies for warm/mild climates
The group I'd like to emphasize here are a series of species found
on islands and shores of the Mediterranean Sea. These species grow and
flourish in Mediterranean climates not unlike many comparable sites on the
West Coast, Australia and elsewhere. They come from areas with hot dry
summers, fall and winter rainfall and generally milder climates. These have
rarely been used to produce hybrids which might be more easily grown,
tolerate a wider range of growing conditions and produce a range of plants
suited to growing on the Pacific Coast.
The species I have in mind include P. broteroi, P. clusii, P.
coriacea, P. corsica, P. mascula, P. parnassica, and P. rhodia, and some
geographic forms of P. officinalis, P. pergrina and P. daurica. The island
species include P. clusii from Crete (and elsewhere), P. rhodia from Rhodes
and P. corsica from Corsica and Sardinia as well as isolated ssp. from
various Aegean/Greek islands. P. corsica (also known by the unwieldy P.
cambessdessii) is the most widely grown. There are extremely few hybrids
involving any of these species.
These ten species make up more than a third of all known species
and have great potential for producing a new range of garden peonies for
mild and Mediterranean climates. Because most hybrid peonies were developed
in cooler to cold temperate climates, where these mild climate species are
not easily grown, they were never incorporated*. Since there is the belief
that peonies cannot be grown in mild climates, there seem to be few efforts
to grow these species in mild climates and no one actively growing and
hybridizing these mild climate species. Most of these are difficult to
obtain as plants, but seeds are often available from a variety of specialty
suppliers. Some can grow to blooming size in as few as three or four years
and as short as two years.
I believe that a person dedicated to growing a range of these
milder climate species, understanding their needs and following a planned
series of controlled crosses, including these and more northerly species,
could produce a whole new set of plants suited to many mild climates, not
just Mediterranean climates. Plants that did not require long cold dormant
periods would be well suited to Mediterranean climates, Australia, the
American mid-South, South Africa and elsewhere.
Species and cultivar selection are very important to success in
growing peonies on the west coast particularly as you proceed from north to
south. Paige Woodward's Pacific Rim Nursery successfully grows a wide
variety of peonies; slightly south Jane McGary has reported considerable
success. In the interior valley near Sonoma, CA, a new hybridizer has
produced some interesting hybrids between herbaceous and tree peonies;
these intersectional peonies are the plants of the future.
Generally the farther south you are the less likely your success
with P. lactiflora and its many common cvs. I'd be very interested in
learnging who has success with herbaceous and tree peonies and what
Mediterranean peonies are actually grown by PBS members. Does anyone in a
colder climate have success with Mediterranean peonies?
And one important reminder: All peonies do best if planted, replanted,
divided or moved in fall ONLY when dormant. Doing so in spring is likely to
cause stress for all involved and by all means avoid boxed dried up peony
roots in spring. So this is the time to consider planting peonies.
And finally a small commercial plug for the new book 'The Genus
Paeonia' by Josef Halda and myself (Timber Press, 2004), the most recent
complete generic revision. I also recommend 'Peonies' by Al Rogers, now out
of print, but a paper back version due very soon. Appreciate all comments
and experiences.
Best Jim W.
* There are a few exceptions.
--
Dr. James W. Waddick
8871 NW Brostrom Rd.
Kansas City Missouri 64152-2711
USA
Ph. 816-746-1949
E-fax 419-781-8594
Zone 5 Record low -23F
Summer 100F +