Seedling treatment
The fan is oscillating and the grow racks are slowly filling up. Parsley—curly and flat-leaf—are underway, and there’s more lettuce and some herbs… Fanning the seedlings is particularly satisfying because it does a lot for such a simple thing. I forget where I heard about it, probably from a book, and I’ve been doing it since Year 1 or 2. The idea is that plants develop differently when they have to deal with wind, or rain, or otherwise being pushed about. Seedlings raised indoors lead an extremely sheltered life; providing a bit of a breeze toughens them up, and this sort of mechanical stimulation (brushing is another approach) also encourages stockier growth instead of stretching. It makes sense to me—seedlings definitely wouldn’t be so coddled growing out in the field! I don’t follow a particular schedule, just give ‘em at least an hour or two a day, sometimes more, turn the fan on and move it around every once in a while. It’s easy, sounds good, hasn’t hurt! (I couldn’t remember the arcane term for this, so I hunted it down online and wasn’t disappointed: thigmomorphogenesis! While at it, found an interesting article as well.) The fanning also dries the soil surface, which helps prevent damping-off, so you can’t lose!
Somewhat related posts: • Seedling action • Trimming leeks • Cucurbits germinate! • Carrot science • Called for wind
VP said,
February 11, 2008 @ 10:39 am
This is a great idea Mike! I brush my seedlings once a day to do the same thing but I don’t have to do it on an ‘industrial’ scale like you do :)
Gillian said,
February 11, 2008 @ 11:56 am
Will this stop the sprouts from looking so spindly? I tried growing herbs from seed indoors a few years ago and a lot of them - particularly the cilantro - grew so tall and thin that they looked sickly. Many of them died during the transplanting. I am worried that I will have the same problem this year and won’t know how to fix it.
Clemmons said,
February 11, 2008 @ 1:10 pm
Gillian, the fanning will toughen them up and make them thicker and less spindly. I have always used a fan like this and it works. I daily rotate the plants or move the fan around so it isn’t always blowing from the same direction.
Gillian said,
February 11, 2008 @ 3:48 pm
Thanks Clemmons! :)
Mike (tfb) said,
February 11, 2008 @ 7:03 pm
Gillian: The wind should help! You may also need more light. I’ve noticed that some plants like coriander, parsley, and lettuce that stretch in the first week or two from not enough light, will flop down, the stems are too thin to ever pick it up again, and as they grow, you get this tangled, viny mass of stretched stems that’s hard to transplant. So you may want to experiment by giving a few seedlings lots of light right from the start, like, if you’re using fluorescents, keep it only three inches or so from the leaves. Plus the wind! Don’t forget, wind also dries out plants really efficiently, so make sure they’re well watered. Then, see what happens! :)
tech_sam said,
February 11, 2008 @ 7:30 pm
Excellent stuff! We have a ceiling fan, which might be good enough for circulation, but I will set up the clip on fans to stimulate stem strength.
Christine said,
February 11, 2008 @ 8:06 pm
I have been starting seeds indoors for years, and I have never heard of this. Wow, it makes sense, though. Love the pictures of your seedlings.