Bulbs for Continental climates, Upper Midwest--TOW

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
source.

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
Member of INTERNATIONAL CLIVIA CO-OP