As an alternative to poring
over the actual peony bloom time data, some summary information is presented
here without all of the details. The article is organized around the idea
that the peony enthusiast can have seven weeks of bloom. Not many of us
will choose to plant for all seven weeks but it is very easy to obtain
four or five weeks of bloom.
Table 1 provides information on the distribution of cultivars
by the weeks in which they first bloom. I took all the cultivars in the
bloom data and asked what percent start to bloom in week one, week two
etc. The answer is in the Table below.
Our data does not contain
every cultivar but I believe that the distribution of blooming time shown
in Table 1 is a reasonable approximation to the cultivars
that are currently commercially available. I have no way to prove that
my belief is correct and you should keep this limitation in mind. If one
considers the set of all named cultivars (whether in commerce or not),
my belief would change.
There are many more older
lactifloras that are not currently available and this would change the
distribution. The percentages in Weeks Five and Six, and perhaps Seven
would be even larger. The percentages in the other weeks would fall although
the pattern, a slow increase across the early weeks, would not change.
There is a huge peak in Week Five when almost one-half of the cultivars
start to bloom. In addition, there are many cultivars that begin to bloom
in the week preceding and the week after the Peak Week. These three weeks,
Weeks Four, Five and Six, contain about 85% of the cultivars and represent
the common blooming period that we are all used to enjoying.
If one wants a very long peony season, one has to select the early blooming
varieties. There are three weeks of possible bloom before Week Four and
only one week after Week Six. It is the long early bloom period that is
attractive to peony enthusiasts.
In Southern Ontario, where I live, the peak, Week Five, would be about
June 4th to 10th. These dates will vary with your location. Colder locations
will have to wait a little longer and warmer location will see the peak
earlier. Week Two will begin here about mid-May.
For each of the seven weeks, I will provide some examples of the cultivars
that bloom during this period. The selections are biassed towards cultivars
that are available and that perform well.
Table 2 provides examples for the first three weeks. Week
One belongs to the species. These are not as widely available in Canada
as in Europe but can be found. At the very end of this week, the Fernleaf
peony and its hybrids, e.g. 'Little Red Gem' will begin to bloom.. A small
number of Saunders' hybrids, such as 'Nova' will also bloom in Week One
||Claire de Lune
|Little Red Gem
||Hana Kisoi (TP)
TP = Tree peony
Week Two continues with further hybrids of the Fernleaf peony, for example,
'Early Scout' and 'Laddie', P. Officinalis and its hybrids also
begin to bloom in this week along with more of Saunders Hybrids.
Although our information on bloom dates for tree peonies is very limited,
some tree peonies will begin to bloom in Week Two and one example is given
in Table 2.
The bulk of the tree peonies
will bloom in Weeks Three and Four with a few starting in Week Five. Because
our data is so limited, we will not discuss tree peonies in any detail.
The volume of hybrid cultivars increases substantially in Week Three.
There are now more gorgeous semi-doubles to accompany the singles. There
are still no lactifloras but there are many hybrid varieties from which
to choose. A few examples are shown in Table 2.
In Table 3, we provide a few examples of the cultivars that
begin to bloom in Weeks Four and Five. The hybrids continue to dominate
in Week Four although the earliest lactifloras will start to bloom by
the end of this week.
||M. Jules Elie
|Mme de Verneville
||Mrs. F.D. Roosevelt
The choice of cultivars is
very large in Week Four and even larger in Week Five. Almost one in six
cultivars begins to bloom in Week Four and almost one in two in Week Five.
In Table 3, I have used two columns for Week Five to increase
the number of examples. These twelve cultivars are only a tiny portion
of the more than 300 cultivars in our data that will begin their blooming
in Week Five.
Week Six continues to offer
a very large range of choice of lactifloras. A few of these are shown
in Table 4.
Many of the best known Japanese
form peonies will bloom in this week. If one wants to have some contrast
in flower form, it will be these Japanese that offset the numerous doubles
There may only be only six and one-half weeks of bloom. Very few cultivars
reliably bloom in Week Seven. You may find, as I have, that cultivars
listed in Week Six bloom later than some of those listed for Week Seven.
The late blooming cultivars are all sensitive to the weather patterns
in a given year. If summer heat arrives early, many of the cultivars in
Weeks Five, Six and Seven may open very close together. With a gentler
climate or a slow onset of summer many of us can enjoy a longer period
of bloom as shown in Table 4.
There are distinct temporal patterns for the different flower forms, single,
Japanese, double etc. During the peak Week Five almost all flower forms
are widely available.
In our data, about 47 percent
of the cultivars are Doubles, 25 percent Single, 14 percent are Japanese
and 14 percent are Semi-Double.
Single blooms start the peony season and are very dominant in Weeks One
and Two. Even in Week Three they are the most common bloom type.
At the other end of the season,
there are no singles in Week Seven and very few in Week Six. This flower
form is still widely available in Weeks Four and Five.
Just as the singles become
rarer, the next form begins to bloom. The Japanese have perhaps the shortest
or most compact bloom period.. There are no Japanese cultivars in the
first three Weeks and only a few in Week Four, for example, 'Jewel'.
Japanese cultivars are concentrated in Weeks Five and Six. There are no
very late blooming Japanese cultivars in Week Seven. Examples of the latest
blooming Japanese cultivars are 'Barrington Belle', 'Shaylor's Sunburst'
and 'Sword Dance'.
Semi-Double cultivars span a longer bloom period than the Japanese cultivars.
There are many early hybrid Semi-Double cultivars whereas there are almost
no Japanese hybrids - 'Jewel' and 'Walter Mains' are hybrid Japanese exceptions.
In Weeks One and Two, Semi-Double cultivars are rare but not unknown.
It is the hybrid semi-doubles of Weeks Three and particularly Week Four
that form the most important season for this bloom type. There are almost
no Japanese hybrids and in contrast there are relatively few Semi-Double
lactifloras. There are some, but Semi-Doubles are rare in Weeks Six and
none bloom in Week Seven..
The most numerous flower type are Doubles. These are scarce during the
first two weeks. The exceptions are 'P officinalis. A few more start to
bloom in Week Three but these are uncommon cultivars that are not readily
The Doubles take over in Week
Four and provide much of the bloom for the remainder of the season. In
the last two weeks, the predominant forms will be the Japanese and the
In my garden, I have the impression that the passage of time brings a
change in the predominance of different bloom colours. This may reflect
my choice of cultivars. I looked at the data to see if my impression could
be supported by evidence. In general, the answer is no or that the evidence
is quite limited.
Hybrids and Lactifloras
The term hybrid peony conjures up images of vivid colours and early blooming.
As noted above, the hybrids (and species) dominate the season from Week
One through Week Four. The lactifloras take over and carry most of the
bloom for the last three weeks.
During Week Five, the hybrids continue to offer their vivid colours although
numerically they are dominated by the lactifloras. During this week, most
of the coral hybrids bloom as well as some Double and Japanese hybrids.
By Week Six, the hybrids are finished and the lactifloras carry on for
the remainder of the season.
This brief summary can not convey the range of choice available. There
is a definite bloom peak and if one grows very few peonies there are excellent
choices at the peak times. As one grows more peonies, it is worth considering
more of the early hybrids and species both for their vibrant colours and
for the increase in the length of the peony season.