Silverhill Seeds, hardiness

J.E. Shields
Sat, 07 Feb 2004 08:33:58 PST
Joe, Ken, and all,

Good points.  I am most interested in the hardy and almost-hardy 
bulbs.  After all, I have a lot more space to grow things outdoors than I 
do under glass and plastic.

Hardiness outdoors here in mid-zone 5 is very important to me.  However, 
zone 5 in Indiana is a wet zone, with almost 40 inches of precipitation (as 
liquid) each year.  We get at least 2 inches per month, and obviously we 
often get more than that.  The plants from arid and semi-arid climates are 
more likely to suffer from the moisture here.

We cannot grow Kniphofia hirsuta, citrina, sarmentosa or stricta out in the 
open.  They seem to survive in protected spots outdoors, such as next to 
the southeastern corner of one of the greenhouses.  the stricta and the 
citrina seem to bloom sometimes there too.

Kniphofia caulescens survived several years and bloomed once outdoors on 
the south side of a very large Colorado Spruce tree.

Kniphofia northiae survived several years but never bloomed out in the wide 
open spaces of a fully exposed, raised rock garden bed.

I have not tried the K. uvariae hybrids yet.  I planted some K. 
linearifolia outdoors in a raised sandy bed, but I don't think they 
survived.  I'll check again next season to be sure.

Other unexpectedly hardy South African bulbs here are Crinum variabile as 
well as CC. bulbispermum and x-powellii, and [bulbispermum X 
lugardiae];  Gladiolus oppositiflorus salmoneus (but this depends greatly 
on the specific site) while G. dalenii has not survived.  Dierama 
dracomontanum and latifolium survived outdoors in the ground for several 
years in a reactively dry bed.  Morea galpinii has done better than other 
Morea outdoors here, but it is not able to bloom.

Zantedeschia have not survived outdoors in the open ground 
here.  Nevertheless, I keep trying and hoping.  I have one large plant of 
Z. aethiopica 'Green Goddess' planted up against the outside of the south 
wall of one greenhouse, between a couple of surviving crinums.  Maybe it 
too will survive.......    I had numerous seedling pots of Zantedeschia 
seedlings that had survived two winters in a cold frame die last winter in 
the same cold frames.  It was unusually wet last winter, and the 
temperatures stayed below freezing for long periods without any 
thawing.  Too cold and too wet apparently did them in.

I'm always looking for more potentially hardy bulbs to test here.  Do you 
have any you would like me to try here?  There is lots of room out in the 
nursery beds.

Best wishes,
Jim Shields
in central Indiana (USA) where our coldest temperature so far this winter 
was -8 F (about -22 C)

Jim Shields             USDA Zone 5             Shields Gardens, Ltd.
P.O. Box 92              WWW:
Westfield, Indiana 46074, USA
Tel. ++1-317-867-3344     or      toll-free 1-866-449-3344 in USA

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