Last year Downy Mildew decimated my seedlings and I’m starting to see it again this year. After doing some research, reducing the relative humidity near the seedlings seems the best way to control it. So I set up a fan to create an air flow across the seedlings. I have my lights and fan set up on a timer for 16 hours a day. I probably wouldn’t need to have the fan on that long each day but this way I don’t have to remember to turn it on and off each day manually. Does anyone see any down side to having the fan blow across the seedlings that long each day?
Thanks
As long as you remember to water them as needed I don’t see any downy side…ooops, I mean down side… at all. I would leave the fan on low 24/7. Set it up so it’s blowing fairly gently.
Good luck with the downy mildew. That’s a problem that I haven’t had to deal with yet.
I have a fan just blowing in the basement on low and plant stands in different places and a dehumidifier. In the winter now the dehumidifier doesn’t go on very often and it is pretty cool down there. I might have some downy on a cutting a friend from CA sent me. Some of the leaves dropped and the newer ones are coming out and looking okay. Hopefully I can stop it. I want to keep that special plant. The fan doesn’t blow directly on any plant stand, but just keeps the air gently moving through the basement.
This basement isn’t very damp, not like my last basement where I had to have a de-humidifier running all summer long. I’ll probably take both of your suggestions, move the fan farther away from the plants and leave it on 24 hrs a day.
Thanks
I moved the fan farther away from the seedlings and I’m leaving it on 24/7. After removing infected leaves and/or seedlings they’re looking pretty good. The new seedlings are upwind of the infected plants so I hope that helps the curb the spread of it. It‘s a fine line between keeping the soil moist enough so the seeds and seedlings don’t dry out and dry enough to control DM, so I’ve been watering with less water but a little more often. I still see an infected leaf here and there but I think I have it under control, though it’s early yet.
I’d watch that cutting pretty closely David, that’s how I brought DM in last year, rooting some cuttings of my own plants. I didn’t do anything to control it and it spread to the seedlings with rather disastrous results. Quite a few seedlings died from it while many survived but lost all their leaves and they were just bare sticks when I planted them outside. There were some but very few that weren’t affected by it to some degree.