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Breeding Hostas
Each year I talk to more and
more hosta growers that want to try their hand at breeding, so I thought I
would stick my neck out with some thoughts, recommendations and factoids
about breeding hostas. I want to state in the beginning that I don't
consider myself anywhere near the top echelon of hosta breeders, and
that's not just false modesty, it's a fact borne out by the number of years
I've been doing it and the hostas I have introduced.
Collecting and starting hosta
seed is not breeding. Breeding involves choosing the parents and
making the crosses by hand. There is nothing morally wrong with
collecting and starting seed from plants that the bees have pollinated, but
the bees are the breeders, not you. That would make you the bees'
technical assistant. Being the breeder is much more rewarding than
being a bee's flunky.
There are two basic reasons to
try breeding. The first is just to see what happens and learn more
about hostas. The second, to try to produce a hybrid that is good
enough and special enough that other hostaphiles will want one too. The
first is easy and fun, the second is hard and fun.
As close to perfect as our
hostas are, there are many ways that we might improve on near perfection.
I sell quite a few hostas, so I know that people like variegation and huge
leaves. Since most of the largest hostas are not variegated, it seemed
obvious to me that larger variegated plants would be one reasonable goal for
my breeding program. The flowers are another obvious opportunity for
improvement. Without gene splicing we will never get flowers like the
dahlia, or even the more closely related daylily, but there are many
improvements in shape, size, color and fragrance that may be within reach.
There are many other
traits that breeders are trying to attain, improve or combine in their
seedlings: red pigment in the veins, scapes, petioles, and maybe someday the
leaf tissue; pie-crusted and serrated leaf margins; ever larger or tinier
leaves; slug resistance; sun tolerance; and just about anything else we can
think of that someone considers desirable and possibly attainable.
Even with the mind boggling variety already out there, there is always room
for improvement.
Making Crosses
For those who know nothing about
the process, let's talk about baking. About ten or fifteen thousand
years ago, someone mixed flour and water and baked it and got flat bread.
That's Hosta 'Lancifolia', filling and useful, but not very exciting.
But over the years, different people had different ideas and they kept
playing with the flat bread and adding other things to the mix and through
trial and error, probably mostly error, one day we got pizza! Then pepperoni
pizza! OK, that's Hosta 'Blue Angel', a great hosta. It isn't going to
excite too many of today's hosta gourmets, but it will probably always be in
their gardens.
Then a whole bunch of people see
how much fun this is and they start experimenting. They start with a
good pizza and add new ingredients, trying everything they can think of to
come up with something new and better. The more people working on it,
the better the ingredients we use and the more thought we give it, the
better chances we have of coming up with something really good.
Chicken Marengo pizza! Unfortunately, even though we use the best
ingredients, we don't always get what we're looking for, like my Cajun
sausage, Szechuan sauce and blueberry pizza. It's got a lot of good
stuff on it, I really like Cajun and Chinese food, and how can you go wrong
with blueberries? But somehow, it just didn't work. That's about
ninety percent of my seedlings.
OK, enough pizzas. If you're
still with me it's obvious you really want to learn about breeding and have
nowhere else to turn. It's a snowy day in February and I have nothing
else to do.
Making the Crosses
First the basics. There is
nothing more to breeding hostas than taking the pollen from one plant,
and putting it on the flower of another (crossing), or even on the same
plant (selfing). At the same time, you need to make sure that the bees
aren't helping you. There are many ways of physically making the
crosses, applying the pollen with paint brushes, swabs, or whatever. I
simply remove the pollen bearing anther from one plant and rub it on the
stigma of the other. To make sure that the bees don't get there first,
or put unwanted pollen on with mine, I remove the flower petals and the
anthers the evening before the flower opens, leaving the bees no place to
land in the morning.
The photo is not great, but it's
the best I have right now. The parts of the flower we use are the six
male stamens, which have the pollen bearing anthers on the end, and the
single female pistil, which has the stigma on the end which accepts the
pollen.
 In the evening, the buds that
will open the next morning, (A), will swell and are relatively easy to
identify by their size. I simply remove every thing but the pistil
(B). The bees get up earlier than I do, but on this flower, even if
they try to get into the throat, there's no place for them to land and they
usually won't get any pollen on the stigma. In the morning, I simply
remove the stamens, which can be seen on flower (C) and rub them on the
stigma to transfer the pollen. You can see that unlike the stigma
above my finger, which the bees pollinated, the stigma on flower (B) has no
yellow pollen on it. (I had already pollinated the unmarked flower at
the top when I took the picture.) I sometimes leave the anthers on if
I want their pollen, but it is safer to take them off. Others use various
means to keep the bees away from the flowers entirely, which is certainly
more foolproof, but I am not a perfectionist.
On chilly mornings, the pollen
may not ripen until it warms up a bit. When ripe, it is usually bright
yellow and fluffy, and it rubs off easily. At around the same time,
the tip of the stigma gets sticky so the pollen will stay on. Later in the
day, especially when it's hot, the pollen will dry up, so there is an
element of timing involved.
That's all there is to it, you
just have to wait for the seeds to develop, except sometimes they don't.
There are numerous factors that determine whether a cross will actually lead
to seeds, but to begin, all you need to know is that usually it works, but
sometimes it doesn't.
Choosing the Parents
We have to assume that the
objective is to get new hostas that are in some way an improvement over
what's already available. To do that, given the fact that there are
many people who have been doing this for many years, it would seem logical
to use their successes as a starting point, or, much more difficult, to
think of something to try that all those other people haven't thought of
yet. If you think that you might get something interesting using
sieboldiana 'Elegans' as a parent, you have to realize that everybody else
has already been there, done that. Yes, you'll get a lot of blue
hostas that you can plant in your garden, and you might even get a great
plant, but unless you cross it with something very unusual, your chance of
getting something entirely new and different is rather small.
But if you take an introduction from one of the best breeders, and
maybe cross it with one of the species plants that hasn't been in wide
circulation for very long, well then you may be trying something that hasn't
been done before and you might even get something great. Or maybe not.
Just to make things more
interesting, if you are hoping to get variegated seedlings - and just about
everybody is - you don't begin by crossing two variegated hostas. As
logical as that would seem to anyone who has a rudimentary understanding of
genetics, it rarely produces variegated seedlings. To produce
variegated seedling with any efficiency, the mother (pod) plant has to be
streaked. If you are not familiar with streaking in hostas, it's a
subject unto itself, and you can learn a little bit about it and see what it
looks like here. Beyond
the fact that the mother plant has to be streaked, everything else is pretty
much the same.
Picking the parents simply gives
you the means to have some influence on the resulting plants. Other
than variegation, just about any trait in either parent can show up in the
offspring. I'm not going to get into genetics, but if you are going to
try breeding, and don't have at least an elementary knowledge of how this
stuff works, I suggest you get a book or look at some of the articles on the
subject in past issues of the Hosta Journal. I'm sure there is plenty
of information on the web too.
The process of pollinating the
flowers is simplicity itself - it has to be in order for plants to survive.
The art of hybridizing, on the other hand is not so simple.
Hybridizing involves choosing parents and, hopefully, producing offspring
that are in some respect an improvement over the plants that are currently
available. Some hybridizers set out with specific goals in mind and choose
the plants to cross that they hope will contribute the characteristics they
are seeking. Sometimes it takes many generations, involving numerous
parents, to reach the desired results. Others, as one well known
hybridizer puts it, cross "pretty with pretty" and hope to get
something even prettier. Either way, the art is in choosing the
parents, and the better parents you use, the better offspring you are likely
to get. It also involves a lot of luck.
Selecting the "Keepers"
A serious hybridizer can easily
germinate 10,000 seeds in a single year, and might cull them down to a
hundred or fewer plants to grow on. Out of the keepers, several may be
good enough to grow to maturity. Culling is an art in itself. Those
with limited space have to learn to be brutal and quickly discard the
unlikely in order to keep the promising. Even with all the space we
have here, we have to quickly discard at least ninety percent of the plants
that germinate. Unless you are breeding for an easily identifiable
trait, culling is probably the hardest part of the process. Hostas
take years to mature, and some characteristics like puckering, pie crusting,
even leaf size and shape are not always easy to judge until the plants are
several years old. If you are breeding for blue hostas and a seedling
is yellow, you can safely say that it's not what you are looking for.
But if you get a lot of blue seedlings, you have to make an educated guess
as to which one's are likely to be the best four or five years from now.
Several years ago I crossed one
of my plants, 'Uncle Albert' which has unusually large flowers, with
plantaginea, looking to increase the flower size further. While none
of the first generation seedlings had larger flowers, I kept a number of
them to cross among themselves, hoping that the larger flowers would come
out in succeeding generations. It was two years before I found that some of
the seedlings had turned out to be quite promising, despite the fact that
their flowers are not all that big. If I hadn't saved them on the off
chance that they might be useful in further breeding, they would have been
culled when I realized that they didn't have the larger flowers I was
looking for. I suspect that I have thrown out many plants that I'd
love to have back if I could have seen them after two or three years.
How you cull also depends on how
critical you are. We probably germinate 10-20,000 seeds a year, and
have been for about 10 years. That's a lot of seeds. So far, as
of 2003,out of all those seedlings, we have introduced ten of our seedlings.
We have many others that we have high hopes for, but we try to resist the
temptation to name a plant unless we are sure that it is worthy of
introduction. Of course, beauty is in the eye of the beholder.
Some might think we were crazy for throwing out some that we did, and others
might wonder why we introduced the others.
A case history
H. hypoleuca 'Maekawa'
Our hosta 'Uncle Albert' is the
result of a cross of two hosta species, hypoleuca, a form of which is
pictured above, and kikutii var caput avis (sorry, no picture yet).
I use hypoleuca a lot because it often gives us very large
seedlings. It is known as the "white backed hosta" because it has a
white powdery coating on the backside of the leaves. Aside from the fact
that it is an interesting breeding hosta, I wouldn't consider it a great
plant for the average garden. The other parent, caput avis, is known
as the "bird's head hosta" because the shape of its flower bud is said to
resemble the Japanese crane. Its leaves are dark green, long and
pointed, deeply veined, with a low spreading habit. Again, it's interesting
but would not induce drooling in the average gardener.
So, we have two species of
hosta, each with very different characteristics. And what was I expecting to
get when I crossed the two? I had no idea. About the only thing the
plants have in common is that their flower scapes grow horizontally, keeping
the flowers below the foliage, which is not a good thing. But it
seemed that the plants were so different, that their children might be
interesting. Sort of like crossing a poodle with a bulldog.
Well, no, that would be disgusting.
The seedlings were grown for two
years for evaluation, and frankly, were nothing special.
'Uncle Albert' was a result of this cross and it wasn't terribly exciting.
And then, it bloomed.
It had the largest flower head I've ever seen on a hosta.
'Uncle Albert' flower head
compared to 
typical hosta flowers.
So, we got something
different and we named it 'Uncle Albert'. It wasn't a plant that had
much commercial potential. The flowers weren't fragrant, and the
large, tight ball of flowers only lasted a week or two before it started to
elongate and lose its nice shape. But it is an interesting plant with
unusual flowers, and crossing it with other plants might lead to hostas with
large flowers with better foliage, or with even larger flowers, or maybe
huge heads of fragrant flowers. And those might be valuable. (When I
speak of valuable, I don't necessarily mean that money is the objective of
all this. But from my viewpoint, if none of my customers want a plant,
it's a pretty good indication that I haven't accomplished much.)
So, we crossed 'Uncle
Albert' with several different hostas and, lo and behold, we got some of the
most interesting seedlings we've seen here in a long time. The two
below are our favorites, but there are quite a few more that show promise.
Maybe they'll impress you, and maybe not, but look at them in the context of
choosing parents. Neither of these plants have flowers as large as
'Uncle Albert', which was what we were looking for, and neither of them look
anything like the original plants we started with. After just two
generations, using a total of four plants as parents, we have:
tentatively called 'Mustang Sally'.
Sally has gorgeous large, shiny,
deep green leaves on dark red petioles, with wavy edges and nice veining.
I know it's just a green hosta, but I think it's one of the best greens I've
seen. And it's only two years old in this picture.
We also got
which we have named 'Purple Rain'. Medium size blue leaves on
dark purple petioles, nicely cupped with wavy edges. Could be a
winner, but it's been a slow grower for us so far.
They're still young, and of
course they're not variegated, but I think they both have potential.
For those that have to know, 'Mustang Sally' is a hybrid of 'Uncle Albert' x
H. 'Fall Bouquet' (I think). 'Purple Rain' is 'Uncle Albert' x
'Halcyon'. As a frame of reference, they are in three gallon pots.
If you know the parents we
started with, you can see some of their characteristics in the seedlings,
but if I hadn't told you, you probably couldn't guess the parents by looking
at the plants.
Here are a few more plants we
got using 'Uncle Albert' as a pod parent:
We are just starting to
introduce these 'Uncle Albert' hybrids. Those that are currently
available are listed in Our Introductions.
'Big Bopper'
'Dreamboat Annie'
'Miss American Pie'
'Peggy Sue'
So, what have we proven?
That you just never know.
And for those of you that can't
get that bulldog poodle thing out of your head, what you'd get would be a
poodog, and it wouldn't be pretty.
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