They do seed like crazy! But they are not particularly weedy. Think of them as being similar to Iris stylosa but flowering over summer and you have some idea of the conditions and root type.

A fairly loose, even stony, soil with some added compost to hold moisture(not too rich - leaf mould is great) and good sunlight. If you have a continental type summer with dry conditions and high temperatures you may find that some shade over the mid day is appreciated, and some water.

In this zone the plant stays evergreen over winter so you can't count on full dormancy to carry you over the darker and colder days. We usually get a lot of rain over winter, too - far more wet days than frosty. Day temps are usually above 8C.

If you can manage to keep the plant cool-ish, freely drained but with reliable moisture/humidity and, perhaps, enough lighting to give around 6 hours during the day.

If you're growing in a pot do your best to avoid letting it get rootbound. They seem to take ages to 'leave the pot' and grow on in the ground otherwise.