FlytrapCare Carnivorous Plant Forums

Good morning.

Seeking advice on how long I should keep the lights on for my germinating seeds. On 22 Dec I planted 25 red mix seeds. On 1 Jan the first seeds germinated, and as of today, 9 of the 25 have germinated. I did a tremendous amount of research (thanks to this forum) and I am pleased with the progress so far.

I have them on a heating pad (82 degrees) with seran wrap to create humidity (airing out twice a day). They are a few inches away from two BRTLX A60 12W E26 LED Bulb 6000k Cool White.

So far I have kept the lights on 24/7. Would you guys recommend keeping them under the lights continuously?

Attached is a photo of my set up.

Many thanks!

I usually use a 16 hour photoperiod for germinating seeds. That works great — 24/7 is not necessary.

You could probably get by with 12 hours if you really wanted to. I’ve had them germinate outside in the summer, which means they get about 14 total hours of light, and maybe 6-8 direct hours.

Well I did not check your specific bulb but I have checked a Sylvania 12 watt LED 5000k bulb with a PAR meter and I would assume the results would be similar. The DLI (daily light integer) the bulb I checked produced a value of 17 four inches directly below the bulb for a 24 hour lighting cycle. A DLI of 15-20 is considered a good value for VFTs. At a 16 hour light cycle I come up with a DLI of 11. Of course the further horizontally you move from directly beneath the bulb the less light will fall on your plants. So taking all that into account you may want to leave your plants on a 24 hour light cycle until the leaves begin to yellow or it is warm enough to put your plants outside.

You have your heating pad set at 82* but my guess is that at the media surface where the seeds are the temps are perhaps only a degree or two above ambient room temperature. The soil surface is where you need to check the temps. Germination will be slow below 85*. I would remove the seran wrap covering in the next week to reduce the chances of mold or green slime developing.

You have your heating pad set at 82* but my guess is that at the media surface where the seeds are the temps are perhaps only a degree or two above ambient room temperature. The soil surface is where you need to check the temps. Germination will be slow below 85*. I would remove the seran wrap covering in the next week to reduce the chances of mold or green slime developing.

Thank you 1cashew. The thermometer that I have has a thermostat probe. I took the probe and placed it in the media at surface level so that I can better control the temperature on the surface of the soil. it did show a difference in temp once I did. I can adjust the temperature accordingly. It goes up to 101 F. I have set it to 90. Let me know if you think that is a good range. I will remove the seran wrap soon. I have taken great pains in trying to keep the container aired out (twice a day with a fan). I boiled the distilled water and rinsed the media in an attempt to try and stay ahead of the slime and mold. Thanks for the help!

Well I did not check your specific bulb but I have checked a Sylvania 12 watt LED 5000k bulb with a PAR meter and I would assume the results would be similar. The DLI (daily light integer) the bulb I checked produced a value of 17 four inches directly below the bulb for a 24 hour lighting cycle. A DLI of 15-20 is considered a good value for VFTs. At a 16 hour light cycle I come up with a DLI of 11. Of course the further horizontally you move from directly beneath the bulb the less light will fall on your plants. So taking all that into account you may want to leave your plants on a 24 hour light cycle until the leaves begin to yellow or it is warm enough to put your plants outside.

That makes a lot of sense. I have the seeds dispersed in eight two inch net pots. I have kept a documentation of their germination progress. The seeds directly under the lights have germinated (quickly), whereas the ones that are not directly under the lights have not. My immediate action is to rotate the net pots so that the seeds that have not germinated are now directly under the lights. I am also looking into ordering marshydro LED growl light 300W to try and get a more even distribution of light. Again, than you!

85* at the surface is for me ideal, 90* is the upper limit and since you are heating from the bottom you risk over heating your roots as they penetrate into the substrate due to the temperature gradients in your germination chamber media.