Plans

I have my tomato seedlings started.  Plus peppers, celery, lettuces, and a bunch of flowers.  More to come fast on the schedule!

But it bothers me that my plant stand only has 2 bulbs over each shelf.  I use daylight and/or plant light bulbs in them, but it seems my seedlings are always "leggy" (long and thin).  So I decided to change to 4-bulb fixtures to increase the light the seedlings get.

The stand for the seedlings is an awkward size.  Prebuilt shelf systems are 4' long.  But the fixtures are a couple inches longer.  So I have to build one to suit the fixtures.  The important considerations were strength, cost, and ease of construction.  I'm fine with general carpentry, so I sketched and priced several designs...

1.  All plywood - I can make it all 1/2" or 3/4" plywood with a good sanded outside surface.  The "pro" is that it is all same size solid pieces.  Stainable.  Three easy 16" wide sides, top, bottom, and shelves per sheet.  And plywood is stable.  Cons:  Would need 1"x3" board attached to the shelves to resist bending under weight.  And lots of ugly (to a woodworker) plywood edges.

2.  1" board - 1" board frame and shelves.  Pro - Easy wood to handle and cut.  Stainable.  Easy to make dado cuts for solid shelves.  Cons - Have to join two 8" boards to get the 16" depth I need for the 4-bulb fixture on all pieces (sides, top, bottom and shelves).  I can do that and it would be strong, but that's a lot of extra work.  And dado cuts into 1" nominal boards have to be shallow.  Boards more likely to be "unperfectly straight" in all dimensions.

3.  2" board - 2" board frame and shelves.  Larger "glue and screw" edges.  More solid in appearance and actuality.  Little support needed.  No concern about shelves bending under weight. Dadoes can be deeper, so more solid.   2" Boards are usually straight.  Cons - Heavier and inelegant.  Wider dadoes needed.  Bulky-looking.

I considered combinations of 1", 2", and plywood cases and shelves, but didn't see any advantage, and the imagined results were practical but ugly.  The cost of all the above ideas turned out to be from $105 to $128 so the cost is not a concern.

I have decided to go with a solid 2" frame and shelf design.  True, I will have to join 8" boards at the edges, but I have a joiner edger machine and biscuits to attach them flush.  Not as easy as plywood or 1" boards, but stronger.  And something I will be happiest with in the long range.  Those 2" boards will never sag under the weight of the 4 fluorescent bulb fixtures!  I built a plant shelf once; I don't want to have to build another!

The shelves will be of graduated heights.  Shelf #1 is 3" below the lights, shelf #2 is 7", shelf #3 is 10", shelf #4 is 13", and shelf #5 is 16".  That lets me move the seedlings to only a couple inches away from the lamps as they grow.  And with 4 bulbs, much sturdier seedlings anyway!

Oh, and the existing 2 bulb fixture plant stand?    I bought 2 new 4 bulb fixtures.  That will take care of 2 shelves.  The 2 bulb fixtures on the old stand will be removed and doubled under the other shelves so there are 4 bulbs under each one.

The old stand is destined to be moved to the Mews Room to become a cat exploration area with cat-sized holed cut out randomly in the shelves...

Pictures to follow as I build the new plant shelves this week!