Thanks for the question.

I need some more information.  Where are you getting your seeds?  Are they from a seed distributor or are they ones that you harvested from previous plants?  How old are the seeds?  Finally, why are you covering things with cellophane?

After hearing back from you, I should be able to make a better assessment of your situation. Many thanks. 

Hi there!
These are wild harvested seeds. I harvested them in September. I cover all my flats when I germinate seed. It creates a consistent humid environment. It's basically a poor man's germination chamber. I hope that helps!

Thank you!

Hi there!
These are wild harvested seeds. I harvested them in September. I cover all my flats when I germinate seed. It creates a consistent humid environment. It's basically a poor man's germination chamber. I hope that helps!

Thank you!

Thanks for the initial question and your subsequent response. I think that I can help you or at the very least, give you some things to think about.

In looking things over, I note that on 12/6/23 you asked a question regarding the propagation of hoary puccoon. More specifically, you were concerned about the curling of leaves on germinating seedlings. The answer provided suggested either a deficiency of water or hot grow lights. I think that the latter was more likely and, assuming that the growth conditions for the hoary puccoon are the same as what you are using for the Gentiana, there might be a common cause.

I would suggest that your lighting is too intense for good seed germination. With respect to light, PAR can stand for two different things: photosynthetic active radiation or parabolic aluminized reflection. The first term refers to a range of wavelengths whereas the second term is expressed as a single number. Assuming that you are using “PAR” in the second context, it generally is a measure of the bulb’s diameter. One PAR unit is equivalent to 1/8^th inch diameter. With a PAR of 162, this would suggest a bulb diameter of about 20 inches. A bulb this size is rarely used to seed germination. It is more associated with lights associated with, among other things, photography. Compounding your situation is the use of cellophane. This can create a “greenhouse effect” for your plants and lead to a growing temperature that may be too severe for new seedlings. Although I could not tell for sure, I suspect that you had considerable condensation on the underside of the cellophane. In short, I would suggest that this was the cause of your current problem and that which you saw with the hoary puccoon. While such conditions would not necessarily prevent seed germination, they certainly would have a detrimental effect upon subsequent plant growth.

In shorter words yet. Get rid of the LED lights and cellophane. Instead use a shop light fixture using normal fluorescent or grow lights. See:

https://extension.umn.edu/planting-and-growing-guides/lighting-indoor-plants - types-of-grow-lights-2651610

With respect to the Gentiana, they are notorious for difficulty in growing from seed. At the very least, the seeds which you harvested last fall would have needed to be exposed to refrigerator temperatures for two to three months before planting. This is a procedure termed stratification. See:

https://www.bhg.com/gardening/plant-dictionary/perennial/gentian/ - :~:text=Gentian is tough to start,with moist seed starting mix.

https://www.prairiemoon.com/gentiana-puberulenta-downy-gentian-prairie-moon-nursery.html

https://www.illinoiswildflowers.info/prairie/plantx/pr_gentianx.htm

One final comment. I would be curious to know if your current “poor man's germination chamber” has successfully worked for you with other plants. If so, then my suggestion of lighting problems may not be a complete answer to your question. Please look over the sites I suggested, give things some thought, and get back to us with further comments.

Good luck. Thanks for consulting us.

Thank you so much for the thoughtful reply!

I’d be happy to fill in a few more details. I’ve used this general method for years to germinate thousands of plants. In fact, the downy gentians I have still covered are looking happy and healthy. The ones that I uncovered are now all but dead.

You are correct with the stratification requirements. This seed was cold moist stratified for 90 days.

As for the lights, I was using PAR value in the first sense that you mentioned, photosynthetic active radiation. I even regularly grow bottle gentians under them with no issues. I’ll attach a photo of a first year bottle gentian here, just for fun. But these downy gentians don’t like something. It still might be the lights. I will try to construct something to filter the light over them to see if that helps. Thank you again, and I remain open to any further things I should consider!

Thank you so much for the thoughtful reply!

I’d be happy to fill in a few more details. I’ve used this general method for years to germinate thousands of plants. In fact, the downy gentians I have still covered are looking happy and healthy. The ones that I uncovered are now all but dead.

You are correct with the stratification requirements. This seed was cold moist stratified for 90 days.

As for the lights, I was using PAR value in the first sense that you mentioned, photosynthetic active radiation. I even regularly grow bottle gentians under them with no issues. I’ll attach a photo of a first year bottle gentian here, just for fun. But these downy gentians don’t like something. It still might be the lights. I will try to construct something to filter the light over them to see if that helps. Thank you again, and I remain open to any further things I should consider!

Thanks for your response.

Please keep me apprised about your situation. I can’t really think of any other variables at this time. I do believe that the use of cellophane could create too high of a germinating temperature, especially if a heating pad is also involved.

Thanks for using our forum.