zone 5.. is a vast territory ... where are you more specifically ...

with a frost tender perennial in MI.. your target date is 6/1 .. usually bullet proof ...

i suspect z5 kansas city to be much earlier

i personally would tend to later is better.. you want to wake them up a few weeks early.. not be 6 inches tall on transplant ...

another way of thinking about it.. is to figure out when your soil will be warm enough for such ... one would suspect.. with a little googling.. you could predict soil temps at planting level ...

ken

Hmmmm, mine have been sitting, invisibly, in a pot in the greenhouse for over a month. They will get shuffled further to the back or ends of the staging (or underneath) to join the many other pots with various things growing (or not). Sometimes pots can be sitting therefor years, when, out of the blue, a shoot will appear. To be honest, not often though. Mre likely, they will sit, forlornly until I need the space....or the pot....or I have just got bored. Of course, any label will have vanished long ago (during the endless shuffling about), making it something of a crapshoot. I still get pissed with myself for throwing a pot of dormant tulips (the really special T.sprengeri) that had been grown from seed.
Still, back to the ranunculus - these, along with anemones (not the woodsy ones, but the mediterranean types) are usually fails for me. I sometimes get the odd flower but there must be some method which eludes me because, much as I desire these cheerful plants, they rarely survive long under my merciless regime (even when they get the rare 'special' treatment - that is, will actually attempt to follow rules for cultivation).
None of this whingeing is much help to you, Freki - for which I apologise, but,given my dismal record with these plants, I would be passing onto the next post at top speed.

now that campy reminded me.. i too failed twice ... and that was that ... or as they say: and bob's your uncle ....

ken

ken, Lake Ontario (Golden Horshoe). You know the drill... freezing now, mid 20s (70s if you're still using Farenheit) by May. The frost date here was traditionally May 24, but we've been able to plant earlier for the last 5 years. I just don't know how fast these guys start, assuming everything is to their liking. They'll be indoors unless it's over 15 (60 F). They'll winter dormant in a dry pot in my cold cellar.

campanula - my summers are easily hot/sunny enough enough for mediterraneans. IMO UK summers aren't harsh enough for some plants (I lived in Cumbria for a while, where the sheep are mossy :-D )

I planted my bulbs about a month ago ( fretfully upside down!) And they're already 4" tall. We've had 85 degree weather down to high 30's in the last month.