I had really good luck with impatiens this year. I do have a greenhouse, but i don't think it had much to do with them germinating.
I simply threw seeds on damp soil, and kept it damp. The seeds started germinating in about 2 weeks. I have gotten hundreds of seeds to germinate like that.
The seeds were fresh from my plants last summer, but this has been super easy.

I find that the seeds germinate best with constant temperature around 75F and high humidity. I have found that seedlings at the radicle stage are killed by cool night temperatures, anything below 60F-65F depending on the variety.

I agree,super easy.Just sow on moist soil,put under lights and keep moist.Mine are in a room that is around 60 degrees and very dry,so I don't understand all the talk about bottom heat and humidity.I never do this for any seeds and grow hundreds of plants from seed every year with no problems.Why make things complicated,keep things simple and they will grow.

wdc,

Now is a great time to start your impatiens from seed. I started mine super early and already have blooms under lights. Surface sow seeds with something over the top to keep in humidity until after germination. A little bottom heat will speed up germination. Impatien seeds need light also to germinate. They are fairly easy seeds to start but will start off slow but won't take long to get going with good lighting.
I don't know what part of MD you are in but we usually put out impatiens mid to late may which gives you 10 weeks. Mine were blooming within the 10 wk period.

Best of luck.
Dott

I've had the best luck germinating these in coffee filters. Make sure they're in a light area and bottom heat helps.

Deanna