last time I wrote about this subject was in the Summer 2009 issue
of The Hosta Journal (Vol. 40, No. 2, p. 67). The opening
What’s both big and small, and getting a lot of attention?
(mini) hostas. They’re big in popularity, and small in size,
Minis are still hot, perhaps even hotter now.
This year The American Hosta Society initiated a new
size definition for a mature mini or miniature hosta:
Leaf blade area no greater than about
6 square inches (39 square cm.)
The previous (2009)
definition was no greater than about 4 sq. in. (26 sq. cm.). Area
is defined as leaf blade length multiplied by leaf blade width.
Leaf length does not include length of petiole (leaf stem).
Mature is defined as at least five years of good
growth from liner or plug size. Liners are the small plants
wholesaled by tissue-culture propagation laboratories.
Note there is no restriction on clump (mound) height
and width. The 2009 mini size also did not have a limit on clump
In March 2010, an ad hoc committee was formed by the
AHS president to clarify the size of mini hostas in the society.
This was necessary to create uniformity in mini size specification
Hosta Show classifications,
Popularity Poll candidates,
Mini Forum (http://groups.yahoo.com/group/minihosta/)
Burns, AHS Hosta Show Classification List Chair,
“Bob” Olsen, The Hosta
George Schmid, AHS Nomenclature Chair and
“Bob” Solberg, American Hosta Growers Association Liaison.
The size of a mini hosta within the AHS was standardized.
Notably, it encompasses the size criterion used for AHS Hosta Show
classifications. (I’ll discuss this in a few moments.)
Prefixed to 6 sq. inches is "about". This gives needed
“wiggle room” to leaf dimensions, especially leaf blade areas.
Hostas are living growing things and highly precise
measurements of leaf widths and lengths (and I’ll add clump
dimensions too) are not practical. Important contributing factors
are the age of the plant chosen for measurement along with
cultural and environmental conditions. Not surprisingly, there
often is bias – sometimes considerable – in which leaves are
selected to describe a hosta’s size.
At best, most leaf size measurements are +/- 1/16 inch,
probably some only +/- 1/8 inch.
And let’s admit too, some dimensions in registrations,
nursery catalogs and even esteemed reference texts are no more
than guesstimates. They’re what someone thinks the dimensions
might be at maturity. Many hostas are registered before they are
mature. No doubt many sports are registered with their parents’
dimensions because the sports were but two or three years old at
the time of registration.
Differing from previous definitions of a mini hosta, the
new AHS mini requirement includes an interesting new concept: H.
‘Blue Mouse Ears’ (E. & J. Deckert - 2000) is the
“biological standard.” This hosta was selected because many
AHS members, who have ‘Blue Mouse Ears’, know how big it
usually gets and consider it a mini.
Compared to the 2009 mini size,
which is considerably smaller, the 2010 definition permits a
larger selection of hostas to be classified as mini hostas for the
AHS Miniature Popularity Poll. Starting with the 2010 poll, this
is the new name of the AHS (Very) Small Popularity Poll, conducted
by The Hosta Journal
and printed in the summer issue for the last couple of years.
is Garden Standard, not Biological
standard reference hosta for AHS minis was Bob Solberg’s
idea and has considerable merit. However, I would not have
chosen the term “biological standard.” I think it is
inappropriate and perhaps incorrect, implying something
the standard is not. “Biological” is much too
presumptuous, pedantic and academic sounding. At most,
‘Blue Mouse Ears’ (frequently called BME and
pronounced bee-mee) is simply a “garden standard” –
and that’s the terminology I’m using. The American
Hosta Society is a gardening society, not a botanical
Nor would I have chosen BME. A prime reason
is its customary, mature leaf size is at the very end of
the limit of about 6 sq. in. In addition, more and more
we’re seeing old clumps of BME with representative
leaves markedly larger than this size. Often they are as
large as 9 sq. in.; in other words, leaves are about 3
inches by 3 inches. Do you think a hosta with leaves 3
inches by 3 inches is a mini? I don’t!
A better choice, in my opinion, would have
been ‘Pandora’s Box’ (H. Hansen - 1996), ranking
Number 2 in the 2009 AHS (Very) Small Popularity Poll. It
is a variegated-leaved sport of ‘Baby Bunting’ (R.
Savory - 1992). There are several other variegated sports
of ‘Baby Bunting’, but ‘Pandora’s Box’ is the
I did a quickie survey involving two dozen
keen hosta gardeners in summer 2010, mostly at the
exciting FIRST LOOK 10 meeting in New Jersey in June,
asking them: Which would be the better garden standard for
a mini hosta, BME or ‘Pandora’s Box’? All grew both
cultivars. Twenty said ‘Pandora’s Box’.
But to give it its due, BME ranked Number 1
in the 2009 AHS (Very) Small Hosta Pop Poll, and it was
the 2008 American Hosta Growers Association’s Hosta of
the Year (HOTY), a noteworthy, flag-waving achievement.
Most important too, BME is a good grower; it mounds up
nicely and fairly quickly. In fact, it frequently outgrows
the mini site originally allotted to it, especially in
troughs and rock gardens.
Further, to be fair to BME, I need to mention
that some gardeners report difficulty in growing
‘Pandora’s Box’. However, when ‘Pandora’s Box’
likes its site, it’s a showstopper.
Another BME advantage: a dozen or so sports
have been found, some now heavily in the marketplace.
Variegated-leaved BMEs are today’s sought-after mini
hotties. I’m told sales interest in plain-leaved BME has
markedly leveled off: If you’re a hosta fancier, BME is
already in your garden. If it’s not, it isn’t because
you don’t know about BME or can’t find a source.
It’s simply because you don’t want to grow it (for
of the two
BME really a mini?
Another paramount factor for selecting BME as the AHS mini’s
garden standard, I suspect, is BME has a much larger leaf than
‘Pandora’s Box’: maybe twice the size. By having the mini
garden standard at the very upper end of the AHS mini size limit,
other hostas in this dimensional range will be recognized as being
Hosta leaves can have strap, lance, egg, heart (cordate)
or round shapes. A mini size defined only by leaf blade area may
be satisfactory for round and egg- and heart-shaped leaves, but
not always O.K. for certain strap- and lance-shaped leaves. BME
(and ‘Pandora’s Box’ too) have cordate or heart-shaped
foliage. Might having the garden standard for a mini with this
leaf shape imply that minis cannot be strap- or lance shaped too?
Of course this is not intended.
Here are a few outstanding minis not having BME’s
leaf shape. H. ‘Lemon Lime’ (R. Savory - 1977), with
registered leaf dimensions of 3 inches by 1 inch, is Number 8 in
the 2009 AHS (Very) Small Hosta Popularity Poll. H.
‘Alakazaam’ (R. Livingston - 2008) has registered leaves 5
inches by 3/4 inch. Leaves of ‘Bitsy Gold’ (R. Savoy - 1985)
also are 5 inches by 3/4 inches. H. ‘Curly Fries’ (R. Solberg
- 2008) leaves are 5.5 inches by 3/4 inches and ‘Itsy Bitsy
Spider’ (G. Johnson - 2004) leaves are 2.3 inches by 1/2 inch.
Leaf Blade Length: No
may have noted that the new mini size definition has no
restriction on leaf blade length. The 2009 definition
restricted leaf-blade length to no greater than 4.5 inches (11
The problem is paramount for hostas
with very long, very narrow leaves. Here’s a hypothetical
example: Picture a hosta with leaves 11 1/2 inches long and
1/2 inch wide. The new size definition permits this hosta to
be a mini because its leaf blade area is not greater than
about 6 sq. inches. However, I seriously doubt any one would
consider such extreme foliage to be a miniature hosta.
The fix would have been to put a cap
on leaf blade length. A leaf blade length of less than 6
inches would seem to be a good limit, though somewhat less or
more might be O.K. too.
Let me add that there would be a
secondary benefit for a limit on leaf blade length. It also
would limit clump (mound) height. There is this dichotomy: As
long as leaf blade area is no greater than about 6 sq. in.,
technically the height of a mature, AHS mini clump can be any
|| Clump size brings up a very “touchy” – and unresolved –
subject. Mature mound height is used for defining hosta sizes. It
is well recognized that from a practical gardening and landscape
design perspective, this is a much better criterion for defining a
hosta’s size than leaf blade area. That includes minis. Some
hosta reference sources classify hostas by mound sizes, not leaf
blade areas, as do many nurseries for descriptions in their
catalogs and listings
Notable is Mark Zilis’ now classic The
Hostapedia (Rochelle, Illinois: Q & Z Nursery. 2009). It
defines a mini hosta as <8.0 inches mound height, citing H.
venusta as archetypical. (Yes, this highly regarded hosta
authority did not cite either ‘Blue Mouse Ears’ or
‘Pandora’s Box’.) Zilis defines a small hosta as having
mound height of 8 to 12 inches.
Unfortunately, in the nursery trade,
there is no standard mini clump height. Naylor Creek Nursery in
Washington State defines a mini hosta as having height of 3 to 4
inches. Marco Fransen’s Nursery in the Netherlands defines a
mini hosta as having an average clump height of 4 to 8 inches. In
addition Shady Oaks Nursery in Minnesota defines a mini hosta as
having mature clump height of <6 inches.
(While on my soapbox, I’ll complain
that the American Hosta Growers Association has not standardized
on specific mound height sizes for minis and other hostas,
encouraging its members to utilize these designations uniformly
and consistency in descriptions. I would think this would greatly
assist the entire hosta nursery industry; it certainly would
greatly assist gardeners.)
Then there are nurseries that entirely
avoid the issue of what’s a mini size by listing clump and
leaf-blade length and width dimensions without defining size
categories. The purchaser decides if the plant is a mini.
Exemplary is Tony Avent’s Plant Delights Nursery, which
describes hostas by clump height and width, sometimes carefully
prefixed with “at least.”
Since an AHS Hosta Show primarily
features cut leaves, it naturally would follow that their
classification is based on leaf blade dimensions. Obviously, a
classification system based on clump height would be impractical,
probably impossible. Only at AHS Region One’s highly regarded
FIRST LOOK events are entire clumps judged. Most entries are new,
unregistered seedlings and sports. Though preferred, entries do
not need to be mature plants.
You might ask about clump width being a limiting size criterion.
Although the height of mounds more-or-less usually maxes when the
hosta develops maturity, clump width continues to increase with
increasing years of growth. The classic example is H. venusta.
There are clumps estimated to be more than 20 years old that are
greater than several feet in width yet, clump height remains about
Hosta Show’s <6 sq.
The AHS Hosta Show classifies hostas according to registered leaf
dimensions. Leaf blade dimensions in the official registrations
are used to determine whether hostas are classified as mini,
small, etc. The show’s definition of a mini hosta is: leaf blade
area <6 square inches.
Quickly let me say here that
technically “<6 sq. in.” is not the same as “no greater
than about 6 sq. in.” The former excludes leaf blade areas that
are 6 sq. in.; the latter permits leaf blades areas that are 6 sq.
In other words, if a hosta’s leaf blade
length multiplied by its width is 6.0 sq. in. (or greater), it is
not classified as a mini for AHS Hosta Shows. For registered
hostas, Section V is the show’s mini category and all hostas in
Section V have leaf blade areas 5.99 sq. in. and less. (That’s
not 6.0 sq. in. but 5.99 sq. in.) Registered hostas with leaf
blade areas of 6.0 sq. in. and greater are classified as small
hostas, and are Section IV category. The size designation for
Section IV is: leaf blade area of 6 to <30 square inches.
You might better appreciate the
importance of the left-pointing carat, <, prefixing 6 sq. in.
with this example: For AHS Hosta Show classifications, a hosta
with leaves 3.0 inches long by 2.0 inches wide is classified as a
small hosta, while one with leaves 2.9 inches long by 2.0 inches
wide is a mini hosta. Yes, this is “hair splitting” but there
is a numerical divide.
Now let’s be open (or transparent in
today’s political jargon) about this: If anyone thinks that a
leaf designated as 3.0 inches long is significantly – or even
meaningfully – different from one designated as 2.9 inches long,
he or she never has measured any hosta leaves. Or maybe he or she
is “puffing the magic dragon.” However, there has to be some
demarcation between mini and small, and the AHS Hosta Show’s
system has worked O.K. for many years. It ain’t broken; no fix
it needed. I advocate no change.
Simply keep this in mind: All hostas
classified as minis for AHS Hosta Shows comply with the 2010 AHS
mini size criterion, but all AHS mini hostas may not comply with
the AHS Hosta Show mini classification. I suspect it’s only a
few. If they happen to be outstandingly significant in the world
of hostas, they always can be treated as exceptions.
It must be recognized and accepted
that show classification folks cannot be expected to make
pragmatic judgments on the correctness of dimensions recorded in
registrations. They cannot be expected to change dimensions in the
official registry. Nor can they be expected to use dimensional
information from other resources. They are locked into what’s
recorded in the registrations. Arithmetically, with consistency,
they use the formula of leaf length × leaf width = leaf blade
area: those with values of <6 sq. in. are mini hostas for AHS
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