Bulbs for Continental climates, Upper Midwest--TOW

J.E. Shields jshields104@insightbb.com
Mon, 21 Apr 2003 09:13:46 PDT
Hi all,

This would be the TOW when I am about to leave town!  I'll be back on May 
1st, if there is any hangover from this week's TOW to be dealt with then.

Chicago Botanic Garden seems to have some unique microenvironments that 
allow some fairly dicey bulbs to survive as perennials.  I can't grow all 
the types that they can.  On the other hand, I can grow some pretty 
interesting and attractive bulbs here.

I am in USDA cold zone 5 here in the middle of Indiana, AHS heat zone 
probably 6, and Sunset zone 41.  We get rainfall all year round, totalling 
around 39 inches per year (1000 mm), distributed fairly uniformly though 
all the months.  Elevation is abut 800 to 900 ft. above sea level (ca. 250 
meters above mean sea level).  The Great Lakes are about 200 miles (ca. 300 
km) north of here and the Gulf of Mexico is about 1000 miles (1600 km) south.

Arisaema -- there are loads of hardy Arisaema from China that are just 
aching to be planted in your shade garden.  Out in my woodland garden, the 
Arisaema are starting to come up. AA.
ringens, sikokianum, sazensoo (in bloom), serratum (in bloom), and 
triphyllum are coming up. A. triphyllum was in bloom on Sunday 80 miles 
from here in west-central Indiana. They are all looking fat and healthy as 
they start to come up.  All have survived at least 3 winters here (my 
definition of "hardy").  I am trying more, and will try additional hardy 
sorts as I can find them.

Corydalis are another grossly under-appreciated group.  The trick is to get 
the bulbs fresh!  I personally recommend Mr. Janis Ruksans in Latvia as a 

Corydalis solida is as common as dirt in many places in the world, but not 
here.  Where I tried to naturalize it in a  lightly shaded grassy area, it 
has at best struggled to survive.  Where I planted it in the woods, it is 
thriving.  C. solida 'George P. Baker' (brick red) and C. solida 'Beth 
Evans' (rosy pink) are two very fine named cultivars that are doing quite 
well in my woodland garden.

Corydalis angustifolia 'Georgian White' is available from Ruksans, and is 
doing well in a sunny spot in a sandy loamy bed at the southeast corner of 
my woodland garden.  It is the first to bloom here.   Also doing well there 
are CC. kusnetzovii and vittata.  At the northwest corner in another sandy 
bed with leaf mould in it, CC. paczoskii and  turczaninowii are doing 
well.  "Doing well" means surviving, increasing slowly, and blooming.

Corydalis bracteata with large yellow flowers is just now blooming in a 
raised north facing bed near our front door.  The soil there is heavy black 
clay-loam.  C. bracteata is not thriving, but is hanging on and blooming in 
what is probably not a very good spot.  I think I'll move them to the edge 
of the woodland garden as soon as they go dormant.  This one is a very fine 
plant and highly recommended by me!

Cyclamen are tricky to grow here as hardy bulbs.  In some places outdoors, 
they last a couple years then disappear.  In others, they hang on but never 
bloom.  In one spot, in a sand plus leaf mould bed at the base of a tall 
tree, the Cyclamen hederifolium are doing OK.  They have bloomed the past 
two autumns in this particular spot.

Cyclamen coum is hanging on in a few places but has never bloomed outdoors 
here.  It is much better as a winter blooming plant in the greenhouse.  CC. 
purpurascens, cilicicum, and graecum are also great pot plants in the 
winter greenhouse.  Some people can grow Corydalis purpurascens outdoors in 
the ground in cold areas, but I've not done well with it there.

Crinums grow outdoors in the ground here, if heavily mulched or in a very 
protected spot.  I keep trying new ones.  Crinum variabile is a 
sleeper:  The only South African crinum native to the winter rainfall 
region, it grows well here in summer and survives winter dormant and below 
ground.  If you can find it, try it!

Crinum 'Ellen Bosanquet' seems to be fairly hardy here in a well protected 
spot near a south foundation.  This is a great crinum, and one everyone 
should have.  (No, I do not have C. 'Ellen Bosanquet' for sale, nor C. 
variabile either!)  Be aware that what you get form the mail order mass 
market houses as 'Ellen Bosanquet' is NOT.  'Ellen Bosanquet' has flowers 
of a rich burgundy rose color.

I have found that 2-year old seedlings of Crinum [bulbispermum X lugardiae] 
have survived the past winter lined out in the field and covered with 6" of 
wood chip mulch.  I suspect that most bulbispermum hybrids will be 
relatively hardy in the Midwest if planted deep and mulched heavily in 
winter.  I intend to try [bulbispermum X macowanii] and [bulbispermum X 
graminicola] in future years.

I'll get another installment on this TOW off later today.

Jim Shields
in central Indiana (USA)
Latitude 40 N, Longitude ca 83 W.

Jim Shields             USDA Zone 5             Shields Gardens, Ltd.
P.O. Box 92              WWW:    http://www.shieldsgardens.com/
Westfield, Indiana 46074, USA                   Tel. +1-317-896-3925

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