Hi Kristina:
I think that you should be okay with non-organic stock. It's best to get 
high-quality stock because it's fruit will have the best natural protection 
against disease/pests. And I think that another important factor is your use 
of organic fertilizers. -- Marilyn
http://attra.ncat.org/attra-pub/fruitover.html
"Sources of Planting Stock


It is important to get clean planting stock. Buying from reputable nurseries 
that provide stock certified by state inspectors to be free of diseases and 
insect pests is best. Organic planting stock is required, if commercially 
available, for certified organic fruit production. If organic planting stock 
is not available, organic growers must document their search for organic 
stock and its lack of commercial availability. Most certifiers interpret the 
organic standards as requiring organic management of non-organic planting 
stock for at least 12 months before harvesting a crop that is to be sold as 
certified organic. With newly planted tree crops, this is a non-issue, since 
they generally grow for at least three years before producing a marketable 
crop. "