Here's what I see in one germination database (not from experience):
- 30-90 days to germinate. Slow and irregular germination.
- Needs light. Sow on surface.
- Germinate at 65-75F in peaty medium.
On the other hand, Tom Clothier says this:
Nerium oleander , Sow at 23ºC (73ºF), germination in about two wks
You may have to wait for a useful answer from someone with a clue.
>> "in my greenhouse so it was plenty warm and there was quite a bit of moisture on the plastic top but I was still misting a couple of times daily if needed"
My first thought was that it sounded wetter than ideal. With the kinds of seeds I'm used to starting inside my house, if the humidity dome gets drippy, the soil mix is too wet. I think the idea humidity level just fogs it a little, sometimes.
But I understand if "on the surface" needs more humidity than seeds sowed 1/16th inch deep.
Also, a hot environment like a greenhouse can make "steam" from damp potting mix and a plastic dome. Maybe the greenhouse PLUS the plastic humidity dome are making the soil hotter than is idea for the seeds?
