Reticulata
Iris - Creating A Rainbow
By Alan McMurtrie
Reticulata
Facts
|
bloom starts right as the snow disappears
|
traditionally used in rock gardens
|
produces a wonderful perfume on warm days
|
best if replanted and thinned out every 2
years
|
prevent ink spot by providing good
drainage, particularly when the leaves are dying down
|
from eastern Turkey, Syria, Iran, and
Caucasus mountains where it's very dry in the summer
|
flowers 21/2-41/2 inches tall (6.5-12 cm), typically 21/4 inches in diameter
(6 cm)
|
leaves are square to octagonal in cross
section
|
leaves grow to 18-24 inches (45-65 cm)
by the time they die down in early Summer
|
bulbs have a netted covering (i.e.
reticulate)
|
5 years typically from seed to blooming
plant
|
most are 2n = 20
|
histrioides
and winogradowii are 2n = 16, but
they are genetically different
|
danfordiae,
sophenensis, and the Retic from
Çat, Turkey are 2n = 18
|
I
started hybridizing these wonderful early-blooming Iris in 1983. Since then I have opened up a whole new world
that was never thought possible. I did
this by crossing Iris sophenensis, a
diploid form of Iris danfordiae, and
an unnamed species that I collected near Çat, Turkey. All three species are
notorious for "shattering": producing lots of little rice-grain size
bulblets, along with main bulbs that are too small to bloom the following
year. The new hybrids however, are
showing hybrid vigor, in most cases blooming consistently year after year. As can be expected in any varied population,
there are good doers and poor ones, but fortunately more of the former.
Until now, Reticulata Iris have
mainly been available in shades of blue, violet, and purple. In the 1970s, William van Eeden produced the
near-white 'Natasha', now grown commercially.
Many find it weak, but to-date it is the best white available. The
commercial clone of the lemon-yellow Iris
danfordiae is a triploid, with three
rather than the normal two sets of chromosomes, and thus is sterile. Many rock gardeners grow E. B. Anderson's famous
hybrid 'Katharine Hodgkin', whose parents are the pale yellow I. winogradowii
and blue I. histrioides. Its dark blue spotting on cream ground with
yellow flash is stunning. The cross has
since been repeated, and several other named varieties are now available, such
as 'Frank Elder' and 'Sheila Anne Germany'.
All are sterile even though both parents have the same chromosome count
(2n = 16), so hybridizers can take them no further.
When Wim de Goede, a commercial
bulb grower in Holland, saw my first generation hybrids between sophenensis and danfordiae in 1997, he said they were nice, but "just
blues." I understood what he meant
- that there are already lots of blues in commerce. Now, however, I have moved well beyond
"just blues." Orange for example
is just around the corner. I'd like to
tell you how I got to where I am today, and why. I will give you an overview of my results so
far and the color breaks obtained, along with what I'm doing to make these
varieties available commercially, and finally give you a little cultural
information.
For additional information,
including numerous pictures, visit www.Reticulatas.com
A Door Starts To Open
In 1994 my first sophenensis x danfordiae hybrids (hereafter sxd), started to bloom -16 clones
from 3 crosses. I expected them to be
sterile because they were believed to have different chromosome counts. Nevertheless, I felt I had to try some
crosses. My best chance was
intercrossing them amongst themselves, so I did. To my pleasant surprise, I got 130 seeds from
11 successful crosses.
I knew fellow Iris enthusiasts
like Brian Mathew would be skeptical. Although the seed appeared to be good, it
might die when it tried to germinate owing to lethal genes. For example, out of more than 300 crosses and
more than 4800 seemingly good seeds from diploid danfordiae, only 4 or 5 have produced blooming bulbs (with the
exception of those involving sophenensis,
Çat, and of course selfed danfordiae).
The first F2 hybrid bulbs
flowered five years later, in 1999. 94-HW-1 ('Starlight') is white with lovely
blue accents and a touch of yellow. I
couldn't have asked for anything lovelier.
I had expected sophenensis'
veining would be a dominant "feature" that would take generations to
eliminate. To top it off, 94-HW-1 is
proving to be a good doer. The second
hybrid was 94-GU-1, a small pale blue with a bit of yellow influence.
The next year, more of the 1994 F2s bloomed, along with a
couple from 1996. Surprisingly, many of
these were whites with a similar pattern to 94-HW-1. I often refer to this group as
"white-blues" or "white with blue accents." The white of 96-DZ-1 is absolutely pure
white. When light hits its petals they
glisten just like fresh snow on a bright sunny day. I also like the soft blue on its style arms,
and the way the blue veins merge with very pale yellow around its fall
ridge. Unfortunately it doesn't appear
to do quite as well as some others. That
year my first yellow hybrid also bloomed, appearing rather like a more
green-spotted danfordiae. Most amazing of all was a beautiful new
pattern that I'm calling "spotted light blue-green," coming from a
back cross to danfordiae. 96-BN-1 is breathtaking: large blue-green
spots on its fall blade, with a predominant yellow blotch in the middle. The style arms have a blue ridge, with the
inner portion being light yellow-green.
If you look carefully, you will see a pattern similar to Katharine
Hodgkin's.
In 2001 another 13 new F2s
bloomed, many of them yellow-blue combinations.
One of special interest was 94-AT-2: its falls are dark brown on a rich
yellow background. The yellow shows
through mainly around the similarly colored central ridge. Its style arms are several shades of dark
blue.
In 2002 the number
of new F2 sxd hybrids jumped by 36, bring the total to 57. Of particular interest were: 97-CQ-1, which
is sea green in color, becoming intriguingly bluer just as the flowers finish;
three more "Spotted Light Blue-Green" (one without any yellow, making
it a gorgeous spotted powder blue); and two cream hybrids without much blue
influence. In addition, there were three
special 2nd generation clones involving the yet unnamed new purple
species I collected near Çat, Turkey.
One of these I've tentatively named 'Storm' (98-NP-2) because its falls have
dense black veins over a bright yellow background, and its style arms are dark
blue. In sharp contrast, a sibling is
cream with bright yellow around the fall ridge. The third clone is a slightly
lighter yellow than danfordiae with
black (or very dark green) markings on the fall and dark green style ribs
(97-VS-1).
Colour Breaks Involving Çat
Last year 68 new F2 sxd hybrids
bloomed, and then this year there were 100 more. Most amazing was the number of colour breaks
that occurred. In the past I wrote, "I
would classify my second most promising line as involving Çat x danfordiae: 88-AX. I believe their biggest potential is in
intercrossing with sophenensis x danfordiae hybrids." 98-NP is realization of that potential. There are now eleven amazing clones covering
a range from white, to plum, to pale yellow, to rosewood, and there's even one
I can only describe as "chameleon."
All are gorgeous, and of pretty good size too (50 to 60 mm from the tip
of one fall to the tip of another) - gratifying because both the Çat parent and
Iris danfordiae are small. And on top of all that, they all appear to be
good doers. I have to keep pinching
myself to make sure I'm not dreaming!
The potential is also embedded in
about a dozen other crosses that have had a significant number of blooms
to-date. In these cases the only
drawback is the clones are on the small side.
This means they are great for rock gardens. For the mass market, where it seems
"bigger is better", it just means a few more bulbs are need for a "big",
showy, display.
Of particular interest is the
fact several of these hybrids are half way between yellow and orange. According
to the RHS colour chart they are 23A (Yellow-Orange group). In many cases the colour lightens toward yellow
as the flowers age. The most steadfast
is 98-ND-2, who's fall is unmarked other than by a few light dots near the fall
ridge. It's quite striking, and especially so blooming along side the bright
yellow 98-ND-1. If you want something
along that same line that is more than just a pure colour, then 98-00-4 fits
the bill. Its falls are heavily marked
with lots of dark brown dotting, as well as veining towards the outer
edge. It, like most of the yellow-orange
hybrids to bloom so far, has nicely complementing reddish-brown style-rib
stripes. I personally quite like
98-OO-6, which is less orange, but has lovely dark-green style ribs, and nearly
black variable-sized spots on its otherwise evenly colored fall blade.
It's incredible that
yellow-orange has been accomplished in just two generations. The question is no longer "is orange
possible?" Its, "how soon will
we have a large flowered orange?"
Other unusual things starting to
show up are: very dark colours, such as solid dark violet with yellow in the
areas around the fall ridge that would typically be white. There's also a grey, yellow, black
combination that I refer to as 'Evil' (98-GZ-3). You really need to see a picture to truly
appreciate it and ensure you're not visualizing something different. As well, there are several different patterns
of fall dotting, as well as dotting and veining.
Sophenensis x danfordiae Colour Breaks
I have been looking forward to
the day when I could say with a certainty that danfordiae's lemon yellow is actually made up of a number of
different carotenes. This would increase
the range of expression possible in the offspring. We know pale yellow is possible in Reticulata
Irises because of I. winogradowii,
but I want more. To increase the color
range requires the genetic capability to produce the chemical compounds that
give the other colors, along with the genes ("switches") to turn
those expressions on (or off). You can
cross two blue or two purple Reticulatas until you are blue in the face but
you'll never get a yellow, because in all parents the yellow switches are
off. Even though yellow is theoretically
possible, it never has the chance to express itself. This is why my goal has always been to shake
up the genes as much as possible by working with widely varying clones from the
wild. To truly shake everything up and
pull out recessive characteristics takes more than two or three
generations. Then it's a matter of
working to open the secrets which are locked away / hidden (to pull out the
recessive characteristics). We'd all
like to create the 'piece de resistance' right away, but I'm quite pleased with
what I've achieved so far.
Carotenes are fat-soluble
pigments in cell walls that give the yellows, oranges, and pinks we see. It seemed that a number of my hybrids hinted more
was possible, but it hadn't come out and clearly hit me until last year. One of the first to do so was the ameona
98-MN-1. It's styles and standards are
white (with pale greeny-yellow style markings), and it's fall is pale
yellow. This isn't the rich colouring
that will draw you all the way from one side of the garden to the other to see
what it is, but it is lovely. There are
only a limited number of colours / shades that will do this. Ones that are vibrant and vivid, like orange,
or red. Yellow would also be included,
but we already have danfordiae.
98-JI-2 bloomed this year and is
similar. Its flowers have a slightly
different shape, are smaller, and its falls have more dotting. As you might guess, I intercrossed the two and
was rewarded with 54 seeds (an unusually high number).
97-CN-2 is pale yellow with blue
accents: style-arm stripes and fall veining. It's small, 45 mm tip-to-tip, but
has reasonable size standards (2/3 normal height) that narrow to a wisp. For a number of reasons it will probably just
be for breeding purposes. It is striking
and does increase well.
One other colour break that
didn't involve the Çat Retic was 97-BG-1.
Its overall colour is dark reddish brown. This contrasts nicely with its lemon-yellow
ground, which shows on the fall between veins of the overall colour. It's of typical size, with standards that are
half the normal width (4 mm). They are
dull yellow, veined and shaded with the overall flower colour. This nicely accents the flower. The coloring and form are gorgeous, and it
appears to be quite a good doer. I
certainly hadn't been expecting anything like it.
Note Worthy
98-OK-1 (91-FC-1 x danfordiae) was the 6th "spotted
light blue-green" to bloom. This
pattern only occurs occasionally in back crosses to danfordiae. When my wife
Lynda saw it she said it's "icy green." This lead me to giving it the name 'Green
Ice', which rolls off the tongue easier than either 'Icy Green' or 'Ice Green'.
Hopefully it conjures up ice cubes with pleasing green tones in them.
97-DZ-8 is a lovely white with
green and blue accents, plus bits of yellow veining. It has a wide fall blade, but the flower
doesn't open as much as it could; the falls and styles tend to be held upwards
at high angle. As a result the flower
only measured 47 mm from tip to tip. If
it was flatter, another 10 mm could easily be added to its size. Of particular note, its flower had quite good
substance. It remained fresh for quite a
number of days; much longer it seemed than other Retics starting at the same
time. I do hope this characteristic
continues. It would be valuable for both
its commercial success, and for use in hybridizing.
A couple of my yellow-blue
hybrids are particularly interesting.
One I call Tiger (97-AG-6), since it has nice dark green stripes on a
lemon-yellow background. Not quite the
black stripes on orange ground you might have been thinking, but close
enough. There are green dots around the
fall ridge, and the arm portion of the style arms is wholly dark green. Another of interest is 94-AT-2. Its falls are a lovely dark brown on a rich
yellow background. The yellow shows
through mainly around the similarly coloured ridge in the middle of the
fall. Its style arms are numerous shades
of dark blue. Perhaps most interesting
of all is Sea Green (97-CQ-1). I expect
you are either going to love it, or hate it.
It is an evenly coloured blue-green with yellow tones. The area beside the fall ridge is bright
yellow with dark blue-green dots. Its
style arms are much bluer. Just as the
flower finishes it becomes bluer.
Without question it's quite unique.
Bulblets, etc.
As mentioned in the first
paragraph of this article, a common characteristic of Irises danfordiae, sophenensis, the Çat Reticulata, and their hybrids, is that each
bloom-size bulb typically produces about 8 bulblets. If left alone many of these will simply die
because they can't get their leaf above the soil surface - they use up all
their energy trying. It's best to
replant the bulblets close to the soil surface.
In four years they will bloom.
Thus, they can be used to increase a given clone faster than most other
Reticulatas. The problem with the
species themselves is their main bulbs bulbs (which dwindle to almost nothing
during the flowering phase of their annual cycle) don't regenerate large enough
to bloom in subsequent years. This is
why people say danfordiae
"shatters": they find only bulblets and medium-size bulbs (at best)
when they dig up ones planted in previous years. What's needed is plants that regenerate
bloom-size bulbs year after year. The
optimum practice is to plant several bulbs widely spaced, leave them to form
clumps. These would reach an equilibrium
giving perhaps 5 or 6 blooms year after year.
This is exactly what happened with one of my F1 hybrids left behind in a
replanted seedling patch. When I finally
dug up the clump in 2001, it contained 6 bloom-size bulbs, 5 medium, 23 small,
and 163 bulblets.
Occasionally the number of
bulblets produced by a bloom-size bulb can be as high as 25. The main difference between Holland and
Toronto is bulblets get up to bloom-size much faster. They will bloom in just three years, with
some in just 2 years depending on the size of the bulblet. Rate of increase of a given hybrid is not really
an issue in your and my garden - the clone just needs to give consistent bloom
year after year. Before you know it, a
couple of years have gone by and now you have a nice large display. Rate of increase is an issue for a new hybrid
when you want to have enough bulbs to give some to a Dutch bulb grower for
testing, and still have enough for use in hybridizing. It is also an issue if you want to have some
for entry in a show. It is much more of
an issue if you want to build up stock to be able to sell a variety
commercially; especially on the scale of Dutch bulb sales where I hear 25,000
bloom-size bulbs are needed before starting sales.
Some of you may have noticed the
standards are "missing" on some of the sxd hybrids. If you look carefully you will see them, it's
just that they've been reduced significantly in width: 0.3 to 3.0 mm, verses
typical Iris reticulata standard
width of 7 to 10 mm. Two F2 hybrids have
8 mm widths. In terms of length, most F1
standards are 30 mm in length compared to a more typical ~40 mm. Some are only 20 mm. F2 hybrids are much more variable: from 5 mm
to 35 mm. This is of course due to danfordiae, which only has short
bristles for standards. The tips of few
F2 standards narrow to a wisp. Personally I don't really care whether a flower
has standards or not; I'm more concerned with how it looks overall.
Other Hybrids
97-DG-1 is a unique purple with
blue tones. What makes it so striking is
a blue flush around its yellow fall ridge.
The purple and blue contrast is quite distinct. This characteristic comes from a Reticulata I
collected near Van, Turkey. On other
hybrids the effect isn't nearly as intoxicating since the main flower colour is
typically only a slightly different shade of blue or violet.
One colour break outside sxd
breeding was 98-YS-1. It's an ameona:
white standards and styles, with coloured falls (in this case light blue with a
medium blue halo). The YS row was 1998's
catch all for crosses with 3 or less seeds (which typically don't germinate),
or ones orphaned while being counted. A
number of other outstanding hybrids have bloomed over the past 3 years. I can't possibly take time or space to
describe them all here, nor could words do them justice. I would encourage you to take a look at www.Reticulatas.com
A Goal for the Garden
My goal is to create interesting
new hybrids that do well in many North American gardens. I've often heard people complain that they've
bought named varieties, only to have just a few leaves come up after a couple of
years. I've now just about lost 'George'
again, after buying 25 bulbs in 1999. More than six years ago I bought a dozen
bulbs each of danfordiae and I. reticulata hort. (that is, the purple
clone sold under the species name) from a local garden centre. As expected they all bloomed. The following year they each produced 24
flowers. In the third year, and
essentially every year since, there have been only about 6 flowers of reticulata hort., and none of danfordiae. This might seem good from a bulb growers'
perspective because it essentially means people have to buy more bulbs, but in
truth it isn't. Buyers likely end up
disappointed and won't buy more irises; instead, they'll buy something else
that lasts longer.
I really don't know exactly where
I'm going with all of my crosses. I just
know the general direction (actually directions, since there are a number of lines I'm pursuing). It takes 5 years to go from a seed to a
flowering bulb, so, like the captain of a huge cargo ship, I need to make course
corrections well in advance of when I want them to happen. If I wait, it will be too late. This is why I make the number of crosses that
I do. Of course you could easily make
thousands upon thousands of crosses and get absolutely nowhere. The key is to know the theory behind the
practice, then work in several directions at once; you never know exactly which
is going to be the most important.
Starting with widely different clones from the wild is critical. Currently available commercial clones are too
similar to one and another genetically.
Working with two parents that are widely different is like opening up the
potential expression of a 2-dimensional plane, as shown in Figure 1. If the two parents are species, then the
first generation progeny will all be very similar (the "X" in
between) because each parent's genes are essentially uniform. In the second and future generations, by
intercrossing the children plus backcrossing to the parents, the possible range
of expression is the whole plane. It's
up to skill of the hybridizer to bring out this full expression. For example, a recessive gene from one
species and a dominant gene from the other will always give a dominant
expression in the first generation. In
the second generation there's a 1/4 chance the recessive characteristic will be
expressed. In the case of sophenensis x danfordiae, the first generation hybrids are all "just
blues." The second generation
yielded whites, yellows, blues, yellow-blues,
and "spotted light blue-greens."
Now other expressions are starting to appear such as pale yellow
(98-MN-1, 98,JI-2, 97-CN-2), and brown (97-BG-1).
With three widely different
species, the range of expression opens up tremendously. Comparatively speaking, it's 3-dimensional,
as illustrated in Figure 2. These
simplified models give you some idea of how much more is possible using three
species instead of just two. Now if I
could find a fourth species with the same chromosome count (2n = 18), yet
distinct from the others...
Flower Size
Until last year I hadn't ever
paid attention to flower size when I was hybridizing. It wasn't a characteristic I was concerned
about. My highest priority has always
been to work with clones I thought were the most interesting or had the
greatest potential, especially with regard to flower color. After that I would look around to see what
other crosses I should make. If the
flowers were a bit small that wouldn't have stopped me from working with
them. Last year I did specifically
intercross some of the larger clones (85 mm tip to tip). I don't really expect much from those
crosses. They will likely give large
hybrids looking similar to existing ones.
I did manage to measure about 100
of my hybrids last year (a sampling of these are shown). Normally I'm too busy taking pictures and
hybridizing to have time for something like that (I need to retire). However I felt it was important. Bob Pries had asked me the previous summer
what size the flowers were. This was for
several descriptions, but I couldn't tell him because I didn't know. Now I have the grounding to say which hybrids
are indeed small (35 mm tip to tip),
which are typical (50 mm), and which are large (85 mm). This translates to diameters of 40 mm, 58 mm,
and 98 mm respectively. Interestingly three
small flowers would fit in the area of one large flower. As alpine plant growers will be the first to
acknowledge, larger is not necessarily better, its all a matter of proportion. Small flowers are daintier, and simply
require more to fill the same space.
One thing to keep in mind about
flower size is that it does vary somewhat.
The main factor is bulb size.
Bulbs that are borderline as to whether they large enough to bloom or not,
understandably give the smallest flowers.
The figures quoted are for the largest flowers. Generally bulbs that are of a reasonable size
will produce flowers of that size. Since
I was measuring many of my newer hybrids, in a lot of cases I had only one
flower to measure, in others there were no more than three. It was in populations such as 94-HW-1 which I
have more bulbs, and hence a wider variation in bulb sizes, that differences in
flower size could be observed.
|
Çat
ANM2175
|
Danfordiae
ANM2325
|
Danfordiae
hort.
|
sophenensis
|
histrioides -
collected
|
Diameter tip to tip
|
38
|
33
|
45
|
70
|
68
|
Standard - width
|
6
|
-
|
0.5
|
9
|
10
|
Standard - length
|
30
|
-
|
5
|
55
|
43
|
Style lobe width
|
8
|
11
|
17
|
15
|
12
|
Style arm length
|
30
|
25
|
35
|
43
|
35
|
Fall blade width
|
9
|
11
|
13
|
15
|
16
|
Fall length
|
35
|
29
|
35
|
51
|
43
|
Flower - highest point
|
90
|
75
|
95
|
110
|
100
|
Flower - base
|
58
|
50
|
60
|
65
|
60
|
Leaf (longest)
|
60
|
25
|
20
|
55
|
50
|
winogradowii
|
J.S.
Dijt
|
White
Caucasus
|
87-BB-1
|
94-HW-1
(Starlight)
|
97-CQ-1
(Sea
Green)
|
97-DZ-8
|
97-DG-4
|
70
|
50
|
60
|
70
|
60
|
50
|
47
|
60
|
14
|
8
|
7
|
10
|
0.5
|
<0.5
|
<0.5
|
10
|
45
|
45
|
30
|
45
|
15
|
20
|
7
|
45
|
20
|
10
|
10
|
|
15
|
13
|
20
|
13
|
40
|
38
|
35
|
40
|
40
|
35
|
35
|
35
|
21
|
12
|
13
|
16
|
19
|
14
|
16
|
13
|
53
|
45
|
40
|
45
|
45
|
38
|
40
|
43
|
115
|
140
|
85
|
150
|
80
|
85
|
110
|
125
|
55
|
95
|
55
|
100
|
50
|
55
|
80
|
80
|
70
|
80
|
100
|
120
|
45
|
30
|
75
|
95
|
|
97-EQ-3
|
98-MN-1
|
98-NP-4
|
98-NP-10
(Chameleon)
|
98-OK-1
(Green
Ice)
|
98-OO-1
|
Diameter tip to tip
|
85
|
45
|
55
|
50
|
47
|
45
|
Standard - width
|
15
|
3
|
8
|
5
|
<0.5
|
-
|
Standard - length
|
50
|
25
|
30
|
33
|
10
|
-
|
Style lobe width
|
20
|
15
|
16
|
9
|
20
|
13
|
Style arm length
|
45
|
31
|
35
|
35
|
36
|
27
|
Fall blade width
|
20
|
15
|
17
|
14
|
16
|
10
|
Fall length
|
55
|
32
|
45
|
42
|
36
|
30
|
Flower - highest point
|
120
|
85
|
100
|
95
|
100
|
65
|
Flower - base
|
75
|
55
|
65
|
60
|
65
|
35
|
Leaf (longest)
|
125
|
45
|
55
|
90
|
50
|
25
|
Flower Measurements in mm
About 12 years ago, when I had
only a few hybrids, I had time to sketch their flower petals, look them under a
microscope, etc. Now I have a hard time
keeping up, even if I stay up to 1 or 2 in the morning. I now understand why as the bloom season
progresses I get further and further behind.
It's not just simply due to the cumulative effects of getting a bit more
behind each day. It's also because of the additional daylight hours, which
translate into working outside longer, resulting in less time to process
digital pictures, update my web sites, send E-mails, etc.
Genetic
Switches
Now that I have a reasonable
number of F2 sxd progeny, I can start to analyse the high level genetic
switches that are at work. If I had
tried this earlier, I would have come to the wrong conclusions. Fundamentally flower colour is made up of
anthocyans (blues and purples), which are water soluble pigments in each cell's
vacuole, and carotenes (yellows, oranges, and pinks), which are fat soluble
pigments in the cell's walls. True red
is also an anthocyan. Unfortunately it
doesn't appear that Iris have the capability to produce the chemical compounds
that reflect fire-engine red back to our eyes (such as in Geraniums or Roses) -
specifically, the compounds Paeonidin (crimson), Pelargonidin (scarlet), and
Rosinidine (crimson). Reds of a sort are possible in bearded Iris; these maroon
or brownish reds come from combining the right shades of purple and
yellow. To our eye, they combine and
give the illusion of red. This is what
makes 94-AT-2's falls appear dark brown.
It's interesting to look at a fall petal under a microscope to see this.
Moreover, various shades of blue
and purple contribute to the exact colouring we see. Each is controlled by one or more
switches. Think of the flower as a
chemical factory. The genetic switches
control what compounds are produced, and hence what colours are reflected back
to our eyes, from light to dark blue light waves, to violet, through various
shades of purple. Similarly with
yellows, there are a number of switches at work, though with danfordiae's yellow-orange being so
dominant one might think there was only one.
It's a nice colour, but I'm now starting to break its dominance so I can
get at the others. A beautiful pink
Reticulata or rich orange would certainly be nice (perhaps I'm dreaming, but it
turned out to be possible in bearded Iris).
If these anthocyans and carotenes don't combine just the right, you end
up with a muddy mess. I'm amazed every
time I think of all the beautiful things I've created so far.
Detailed analysis of my hybrids
has shown that 2 dominant genes are required to turn blue on, and a recessive
gene is required to turn yellow on:
sophenensis
|
B1B1B2B2
YY
|
danfordiae
|
b1b1b2b2 yy
|
This doesn't explain why three of
the 56 F1s had a reasonable amount of yellow on their falls. Is there a second
path for synthesising yellow involving several genes? At some future point hopefully I'll be better
able to understand what's behind the 'spotted light blue-green' pattern, as
well as the yellow streaking or blotching effect seen on some clones. Of course by that time there will be other
mysteries.
The velvety effect that seems to go along with some Reticulata colours,
particularly dark ones, is due to papilla-shaped epidermal cells (figure
3). It is a physical, not a chemical
phenomenon. If you take a velvety fall
blade such as bakeriana's and turn
it, it shows pure colour at every angle.
You never see any solid white light bouncing off it as you would if the
surface were flat. With Iris petals, you
do see a glistening effect when each of a multitude of cobblestone-shaped cells
reflects white light. The glistening on
the back of a fall is noticeably dull; by comparison, the front of the fall is
"alive". This is due to the
fact that the depth of the cobblestone cells is less on the back of the fall,
where as the front has "hills".
Additionally, the light we see is saturated with colour. Before reaching our eyes it has been bounced
around several times due to the papilla-shaped cells, in the process
"picking up" more and more colour.
This can be seen by the fact that the intensity of colour changes as you
change the angle of the blade.
Currently there are over 40
hectares of Reticulatas under cultivation in Holland, which produce some
50,000,000 bulbs for sale annually. In
1989 there were only 27 hectares, with over 10 hectares each of danfordiae and Iris reticulata hort., followed by 'Harmony' with 31/2. Iris reticulata
hort. has dropped below 6 hectares, while Harmony is about 12, followed by
William van Eeden's 'George' at just over 6.
Pauline and Purple Gem account for another 31/2. My understanding is sales for cultivation in
pots has become a significant portion of the market, and hence separates the
varieties that sell in large numbers from those that sell significantly less.
I now have 6 Dutch bulb growers
testing my hybrids. One is solely interested
in Juno Irises, which I also experiment with -a hobby gone overboard,
effectively a second job. It would be
nice to get something back for all of my hard work and expenses. Following the 2003 bloom, Wim de Goede
proposed to introduce four of my hybrids.
It will still be a few years before enough stock is built up to begin
sales. It will then be a number of years
beyond that before you'll be able to buy my hybrids in your local nursery, but
one day you will be able to!
Did you know that in Holland
large bulbs tend to give two blooms per bulb?
Some of my F1 bulbs I got back from Wim in 1999 were even large enough
to give three, though the third flower was much, much smaller than the first
two. In my own garden I find I get just
one flower per bulb. There was a
point-in-time when I did get two blooms per bulb from some of my typical
Reticulata hybrids. These days my bulbs
are planted too close together, plus I never give the soil a rest from growing
the same the same type of bulbs over and over.
I don't have the space to practice crop rotation. In Holland Reticulatas are planted in the
same soil about every seven years.
I'm pleased to announce my pure
white Reticulata was registered last year as 'White Caucasus' (photo, p.
XX). It's from the lake Sevan region of
the Armenian SSR, hence the reference to the Caucasus mountains. The typical form is purplish; I tend to refer
to it as pinkish-purple since various clones contain differing hues and tones. It will still be a number of years before there
is enough stock to introduce my lovely white form commercially. In order to make this happen sooner, rather
than later, I started increasing it in a lab late in 2002. A few hundred bulbs were delivered at the
beginning of this year, with an additional 2-3,000 ordered for early next year.
Reticulata Culture
Reticulata Irises like
well-drained soil (e.g. sandy loam / sandy topsoil), with lots of moisture in
the early Spring (in the wild and in the colder parts of North America, this is
provided by snow melt). However the soil
should be fairly dry around the time the leaves are starting to turn
brown. They should have at least half a
day of sun. It's a good idea to replant
them every two years or so, and it's best if it's into a new spot in the
garden. In Holland they are treated as
crops, and only planted in the same area every 10 years. This is a luxury I can't afford.
In Toronto Canada Reticulata Iris
generally start blooming at the end of March.
They last for about three and a half weeks, with individual flowers
lasting seven days or longer, depending on temperatures. Sophenensis
x danfordiae hybrids tend to
bloom at the beginning of the season.
If your garden has reliable
winter snow cover, I suggest planting several varieties both where snow first
melts, and in a shaded area where it's the last to leave. That way, you'll extend your bloom season,
and even get to enjoy each variety twice.
Remember, the bulbs need to
regenerate, so the last thing you want to do is disturb them while they're in
growth. Some people find daffodil leaves
messy so they either cut them shorter or tie them up. I certainly don't advise that for
Reticulatas. Wait until the leaves start
to turn brown, then do what you will.
Otherwise you're only ruining next year's bloom!
A little bit of low nitrogen
fertilizer at the beginning of the bloom season is good for bulb
regeneration. Robin Bell would advocate
even more fertilizer.
To Find Out More
Visit www.Reticulatas.com Which are your favorites?
Which
would you like to be able to one-day pick up at your local garden centre?
Alan lives in
Toronto, Canada and has been hybridizing Reticulata Iris for more than 20
years. In 1985 and 1986 he traveled
extensively in Turkey studying both Reticulata and Juno Irises. Alan is an Electical Engineer with more than
25 years experience in computer software applied to the Electrical Utility
industry. During the summer he can be
found canoe camping in Algonquin Park with his two sons.