column covers his picks of the most exciting new hostas soon to be
Chemically Induced Tets:
A Sure Fire Method for Success?
an already popular hosta cultivar and intentionally double its
ploidy. Seems like a sure fire method for success. Such was the case
at the 2010 AHS convention as a trio of chemically induced
tetraploids was unveiled in the vending area. In fact if you
blinked you may have missed them as they all sold out very quickly.
They were “hot” indeed.
The three plants all come from Dutch plantsman Marco
Fransen. The parents of these three sports are all well known and
widely grown: ‘Orange Marmalade’, ‘Paradise Island’ and
‘Praying Hands’. Each of these cultivars has enjoyed a quick
rise in popularity since introduction owing to their unique
characteristics. ‘Orange Marmalade’ adds a new color to the
hosta color palette. ‘Paradise Island’ not only offers red
petioles that contrast nicely with the brilliant yellow spring
foliage, a narrow green margin also frames the yellow foliage
making it even more vivid. And ‘Praying Hands’ is one of the
most unique hostas of all time with its narrow upright folded
In 2007 Marco had the vision to ask a simple question:
“What would these popular cultivars look like if they were
converted to tetraploids?” He also had the industry connections to
make this happen, or at least attempt to make it happen. A lab in
Holland that had prior experience with making lilies tetraploid for
the cut flower business was employed by Marco to attempt the
conversion. While there were no absolutely guarantees of success,
the lab was able to produce a number of selections for each which
Marco could pick from.
Fransen at Trompenburg photo
used to induce polyploidy in plants (like colchicines – derived
from the Autumn Crocus, Colchicum) are often highly poisonous to
humans and must be handled very carefully in the lab. Alternately,
less toxic pre-emergent type chemicals (like Treflan and Surflan)
have been used. Plant exposure to the chemicals yield a wide range
of results - stunting, twisting, changes in foliage color and
variegation. Sometime they die immediately. Sometimes there is no
obvious change at all. Near term survival of many of the resulting
plants can be very short owing to very confused, mixed up
chromosomes. However you are only looking for that one plant that
exhibits the stable characteristics of a tetraploid.
In hostas we usually associate tetraploids with
increased substance, a wider margin with variegated hostas,
stiffer petioles yielding a more upright growing habit, and
slightly larger (wider, not longer) flowers as compared to its
diploid counterpart. That is what Marco was looking for. He made
the final selections based on uniformity to what he had hoped to
achieve in a tetraploid form of the parent plant.
After growing these
selections on for another year, combined with the experience he
already had with the parent plant, he decided these new plants
were ready for introduction. Ben Zonneveld of Holland subsequently
measured all three cultivars using flow cytometry and confirmed
they are all fully tetraploid while the parent in each case is
And so without further adieu let me introduce you to
this trio of titillating tets:
‘Forbidden Fruit’ is tetraploid sport of
‘Orange Marmalade’. It maintains the same unique yellow-orange
color as its parent, but with a wider blue-green margin. With a
little more green in the leaf overall vigor is increased even as a
‘Hands Up’ is a tetraploid sport of ‘Praying
Hands’. It is shorter, stiffer and more upright than its parent.
The yellow margin is more defined and obvious than its parent.
‘Volcano Island’ is a tetraploid sport of
‘Paradise Island’. A wider green margin makes for an even more
striking contrast with the vivid yellow center. A more upright
growing habit helps to really show off the red petioles.
With the investment
Marco has already made in these three new cultivars, it comes as no
surprise that he has also applied for plant patents in both the United
States and in Europe. He is also working on AHS registration. Look
for them all to be more widely available in 2011.
With the success of chemically induced tetraploids, could
an octoploid hosta be far away?