I want to plant a large area of Siberian Iris - about 30 plants. Does anyone know an economical way to buy them and also when is the best time to plant them?
Debrajeanette, I usually divide mine in late summer / early fall, but you can also plant in spring. This is a good guide from the UoM:
The most economical way to 'get' them is to find someone who is dividing a large clump. Otherwise, look for sales at the nurseries or buy from reputable dealers online (I recommend checking out Garden Watch or The Scoop on... for reviews)