Iris--TOW - shade

Diane Whitehead
Thu, 11 Mar 2004 14:53:53 PST
My half-acre garden has become increasingly shady over the last 35 
years, and some irises have ceased flowering as a result.

35 year old bearded of all different sizes still thrive as foliage 
plants, and will flower the year after I do major tree pruning in 
their area.

Siberians also require sun, but not just for the flowers.  Eventually 
the leaves start to grow weakly.

Louisianas have never flowered - too cool in summer, probably, though 
I have them in a sunny spot. We're zone 8 for winter, but most 
summers have 0 "degree days" which I think is days above 30C (?), and 
in the rare years that we do get such a torrid day or two, the nights 
will be much cooler.

I. cristata and unguicularis do OK in shade from deciduous trees, as 
does japonica.

Pacific Coast hybrids and Oregon species thrive and flower in any 
conditions. I am developing ones with up to nine flowers per stem, 
some that bloom in April and again in midsummer, and some that are 
small enough for a rock garden trough. It is exciting every spring to 
see what the new seedlings will be like.

Reticulatas have to be watched assiduously or the slugs will have 
them disappear as soon as the buds emerge.

Diane Whitehead  Victoria, British Columbia, Canada
maritime zone 8
cool mediterranean climate (dry summer, rainy winter - 68 cm annually)
sandy soil

More information about the pbs mailing list