In past years, I have found that germination of impatiens was really hit & miss. I have only had one variety that germinated over 60%.
This year, there were new instructions that I had not seen before. Apparently with some colors and also with some varieties germination is hindered by the "red spectrum" in both artificial and natural light. It is advised to cover the tray with blue plastic for germination.
I have some larger zipplock storage bags for cheese that are blue and taped them on the dome over the seed tray. Last Saturday I had seeded Envoy Orange Star Impatiens and the entire tray has germinated. I will be using the blue plastic for all my impatiens.
Impatiens are surface sowed. Press seed into the soil. I find that misting them daily and keeping the dome on until after the 2nd set of leaves are formed works well. Temperature for germination is between 21ºC & 24ºC, which is 70ºF and 75ºF
