The lights are angled 45 degrees (in a loft on the ceiling/ wall) and are close, from 1-4" away depending on seedling height. They are on for about 18 hours a day. I do have a fungus gnat problem that I’ve been trying to solve with sticky pads and have captured many, but they are still present.
I have used ground up mosquito dunks in my water and on the top of the soil to try and kill fungus gnat larva. My home depot is out of Mosquito pellets.
The leaves are crispy on some of the plums. Growth has slowed or stopped and the leaves that are growing are small. I could take them outside during the day time when it warms up a bit.
Further details
Leaves are browning at the edges first. Some are still green but crispy/ dry and papery. Crispy leaves are mostly near the top, though some are in the mid story. There is not really curling, but the small new ones that are crispy do appear twisted.
I’m using miracle grow potting mix mixed with pearlite. The pots are plastic. I haven’t been feeling the pots weight regulary but have been sticking my finger in the first inch of soil to see if it feels wet. I have tried to not overwater. I do not see roots sticking out the drainage holes. I haven’t fertilized at all. Only what is in the potting mix.
Room is between 64-78 F. Heat vents are not close. I have a humidify on my furnace so my humidity in the room is about 30-40%.
Could be potassium deficiency.
Probably a combination of light intensity and low humidity. If you back the lights way off and almost double the humidity, it will probably help a lot.
Im sorry im still figuring this app out. I didnt see your response until now. When i say back the lights off i mean physically pull them away from your plants. They are being fried. Just imagine a wild plum seedling in the woods, it would be surrounded by thick organic mulch which retains moisture. The dew from the morning would linger because of tree canopy cover. This canopy gives the seedling sunlight but not much direct sunlight.
Plums are fast growing and recover well so you should be good regardless.
Misting the plants will temporarily increase humidity but the lights will dry everything up within minutes. Those lights put out a lot of heat that dries the fresh green growth.
Keep the lights schedule the same, just put some distance between the lights and the seedlings and humidify the room, youd probably need a humidifer, but pulling the lights away will give you a higher relative humidity anyway.
If you want to do this every season consider switching to LED panels, specifically Samsung LM301H diodes. 2, 120w panels should do the job. They are dimmable as well. Kingsbrite is a good brand and can be bought from alibaba(chinese amazon) or off amazon for a little more.
Thanks for your response! I just placed my thermometer right next to the lights and I’m only at 80 F. The lights are LEDs, so they run pretty cool.
Chat gpt said it is salt build up in the soil causing osmotic problems; stated with the confidence of an ignorant AI, which I don’t trust.
I lost seven hybrid pluots to them. I never grew them again. I’m still bummed about it. Maybe next year. One had very cool red leaves. What a shame lost forever.
O nice! I forget they make leds for every bulb now days. Best of luck im sure its not nute lockout. They’ll probably grow to be strong tree/rootstocks. Harsh conditions weed out the weaklings anyways.
Just an update for everyone. Turns out my fungus gnat problem might be more serious than I thought. I’ve implemented a plan of bottom watering, thick layer of play sand on the top, and eventually Mosquito bits (when they arrive). Wish me luck on my campaign of destruction.
Thanks so much for the tip! I have 3-4 seedlings in each pot. Should I pot them up when it’s warm individually and grow up for the season or do you think they would do okay out in the field with heavy mulch and drip irrigation?
