Seedlings stack up

Grow racks packed with seedlings

With the cold snap about to break, the final potting up is fully underway, a few days later than last year, but no worries. Even with the new, fourth grow rack, things are tight, with four trays to a shelf instead of the ideal two—better to give ’em all an equal ration of light for a couple of days until the first wave is out in the greenhouse, than leave some of them on unlit tables. At the same time, started the cucurbits: several varieties of cucumber and summer squash, with melons, winter squash and pumpkins soon to follow. The rain so far has been good, over an inch (25mm) in the last couple of days, and a bit more apparently to come. OK, cool. Then, bring on the heat!

11 thoughts on “Seedlings stack up”

  1. You have So many seedlings! Looks like a lot of work, but also very exciting, expecially when one is trying out new plants. I wish I had equal germination rate in my trays =) Good luck with handling everything further =)

  2. We’re not much farther ahead of you this year, what with a relatively cool spring and some hail which set the garden back a month…but soon its off to the races!

  3. Good Lord I’m jealous of your seedling room.  You should call it ‘the hatchery’ :).  We picked our first ripe tomatoes on Friday, so I shouldn’t be all that jealous, but I am.  I want your lighting system!

  4. I just finished reading the blog from start to finish.  I have to say I really like it and found it very useful. 

  5. Hi!

    I love your blog and this photo is spectacular. I am just beginning a community gardening blog for Columbus, Ohio, so I have you on my google homepage and blog as a source for ideas, inspiration and knowledge. Thanks for writing and posting. If you get a second to check out my blog and offer any advice or comments,  I would be very appreciative!

    Thanks again!

  6. I appreciate this is a really old post but I thought it wouldn’t hurt to ask a quick question in case you had a moment before the late winter/spring workload kicked in. I noticed you were running 4 trays under each light. I appreciate that you mention that 2 would be ideal, but I was curious how this worked out in the end. Leggy plants? or all fine? Every year there are so many starts, and it would be nice not to fire up another 20 lights. Any advice? Thanks for taking the time to put all this together.. quite a journal to look back on!

    • Yeah, exactly: that good ol’ make-do feeling! Not “cheapness,” just kinda common sense, given the economics of it all – get the most out of everything. :)

      Putting four trays under a pair of regular 48″ fluorescents has been effective enough for me. It takes extra work, that you may or may not find “a lot.” The main trick is keeping a close daily eye on every tray, how each different crop and start date is doing, and rotating accordingly.

      Rotating the trays is critical. Literally every inch further from the light and the intensity goes down quite a bit – I bought a light meter and measured! With the old T12 fluorescents, the fatter ones, they’re actually more intense at the middle of the tube, so you are rotating around the center of the shelf, not just from the outside edges lengthwise. The T8s are much more energy-efficient all around and the light even along the tube, so it’s worth adding T8 fixtures when you can. And you can align the trays lengthwise across, as in the pic, and also lengthwise along the length of the shelf, so everyone gets a shot at the best light.

      You have to figure out the frequency of rotation for yourself, by keeping an eye on things. Daily is probably a good start. And you only want to be doing this for as short a time as possible. This post is in May, it’s already quite warm outside, so these guys can head out to the unheated greenhouse pretty quickly. Meanwhile, they can be put out in the sun daily on warm enough days (carried or wheeled, these racks have wheels, although carrying onto big tables is better, more even light…and more work!).

      I also pay attention to the location of the shelf: depending on the room, it can be a few degrees warmer 5′ up on the top shelf than down near the floor, so I keep the smallest seedlings on the top shelves.

      Another tip: The separation between the two tubes makes a difference. If you notice the second fixture from the top on the left, it is one of the old style with the lamps 4-5″ apart – much better than the usual shoplight with the two close together. With my motley assortment of fixtures, I actually have the “better” ones that I favor specifically for some crops (who knows hahaha).

      The final consideration: Are your seedlings getting off to the best start possible? Given that plants just wanna grow, when your results seem good, unless you are carefully measuring and comparing everything every season, and comparing that to performance elsewhere, it’s easy to ignore that changes in your methods could result in significantly improved results. Like, you may think your veg are healthy, tasty, nicely sized, but then find that changing some factor could get you say 25% bigger or faster or more nutrient-dense. So, you pick your battles and your benchmarks.

      Summary: IMHO, use four trays to two fluorescents only when the seedlings can get out in real sunlight pretty quickly, even daily. WATCH CLOSELY and rotate often. And perhaps move trays between shelves when you feel there are better conditions for a particular tray, like a shelf that’s higher/warmer or closer to a window. Fanatical detail stuff. Fun!

      I suppose this could be measured down to a science, which I certainly haven’t done (even with my lil light meter), and some would say it’s not worth the effort, just build more racks or get higher intensity lights, or heat the greenhouse. All options as well, for sure! There are many ways. :)

      Hope that helps!


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