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Sunday, April 1, 2018

Early spring, or is it late winter, tour?

It's snowing right now.  It's not going to snow much, but still, it's April for God's sake. Last weekend, it snowed 3 inches.  Sure, this will be gone tomorrow, but. . . it's April.  The temperatures will be whipsawing from cold to tolerable for several more days.  The mean temperature for March in this area was 41 F, for February 39 F.  Only 2 degrees difference, and February had a few days over 70 F, which March never got near.  At least it has stopped raining.

There's a set of brassicas under the lights that I'd like to get into the beds, but they will have to wait until later this week.  I'd put then in the cold frame, but there's no room in there.  In spite of the bad weather, things are getting accomplished.  The two beds that will get peppers and tomatoes were lightly hoed and seeded with a cover crop of oats and field peas, and a layer of compost was spread over them.  That was two weeks ago and the cover crop still hasn't sprouted.    The large squash bed was seeded with the same cover crop, but no compost.  Today I spaded over two more beds.  One gets brassicas, the other onions, parsnip, carrots and whatever.

Mostly this is about how the seedlings are doing under the LED lights.  So far, not too bad.  The onion seedlings seemed to do OK but they weren't under the lights long enough to draw any conclusions, before they went into the cold frame.  Same with the first batch of lettuce.

Some observations about the lights.  The light spreads out very little, leaving a dead zone for seedlings that are between the lights.  When I moved a pack of lettuce that was in that dead zone to a spot more directly under the light, the plants went under stress and the leaf edges curled.

This is an educated guess about what caused this.  Each light has 2 (out of 225) UV LED lights, and they are both near the center of the light unit.  The manufacturer really should put the UV lights in a different reflector, one that spreads the light over a wider area.  Anyway, I think the lettuce got too much UV and it wasn't happy about it.  Another thing to keep in mind - the plants look very dark under these lights.  That's because most of the lights are red or blue, which is absorbed by the plants.  It's the green and yellow light that passes through.  Anyway, the lettuce, once transplanted into the Earthbox in the coldframe, has been doing fine, albeit growing slowly in these cloudy days:

The solution for the leaf curling problem:  get the lights as far above the plants as possible to allow mixing of the different LED's.  I gave up on the old rope and pulley system used with the fluorescent shop light and fixed the frame that I made for the lights directly to the top shelf of the rack.  When seedlings were started under the T8 fluorescents the light was lowered by two ropes until it was within an inch or two of the seedlings.  That won't work with the LED's because the different lights won't mix that close.  I made some larger reflectors with Reflectix insulation taped to pieces of 1/2" foam board.   I'm hoping the reflectors will contain and bounce around the light so it reaches the lower leaves of the plants. 

Even with the lights that high, the light intensity at the plants is still weaker in the center between the lights and at the ends.  I ordered another light from Growstar to add to these two (hey I'm in it this far, there's no turning back now).  I'll have to remove the light frame and modify it, then install all three lights side by side.   That should eliminate any dead spots for the plants and increase the total intensity for all the plants.  If that doesn't work then I'm out 90 bucks.

Here's another view of the seedlings.  The first set of cole crops has gotten spindly and really needs to go outside.  I don't know that they are any worse than cole crops grown under the T8's.  I'm hoping that the addition of a third light will cure this, if not I may try a small fan to move some air over the plants. Today I seeded tomatoes, eggplant and another set of cole crops, which has filled these two trays.  In about ten days when I transfer the tomatoes and peppers into large pots then space will be at a premium.  I'm hoping that the three lights with the new reflectors will be adequate for four trays side by side.

A closeup of the most recent set of cole crops, lettuce and peppers. The peppers just starting germinating a few days ago.  Yes the plants look very dark but put them in 'normal' light and they look fine.  The lettuce just doesn't seem to like these lights, but I only start lettuce inside to get it to germinate quickly, then move it to the Earthbox.

I haven't discarded the fluorescent light unit.  The shoplight is still there in the bottom half of the seedling rack with the ropes to raise or lower it.  I plan to use it to start seedlings when there's no more room under the LED's.    

Here's another view of the seedling rack.  I had to remove one of the shelves to make way for a two light setup.  After building this rack, my one regret is that it should have been about a foot taller, which would allow for more storage space.  Still, that top shelf can hold a lot of stuff.

I'll end with a picture of the onions in the cold frame.  These are Ruby Ring, Pontiac and Cippolini.  I'm hoping they can go out into the beds in about ten days.

2 comments:

Margaret said...

When you have a new setup, it's all about trial and error, isn't it? I'm sure you will figure out what works best soon enough & hopefully the extra light will help out with that dead spot.

I discovered that I could (and in fact should) position the T5's much higher than the old T12's - 8-12" above the plants vs. a couple of inches. I really like the fact that moving the lights up and down is minimized and it also gives me easy access to the entire tray without having to move it off the shelf.

D2 Bet said...

hopefully the extra light will help out with that dead spot.


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