I spent a few days last week planning this year's vegetable garden. I have BIG plans!! I'm even going to try my best to start most things from seed this year. I've tried many times before, and for various reasons it has not worked well. Like watering, for instance. Did you know that plants don't grow if you don't water them? I can't tell you how many flats of seeds I've set on top of the refrigerator and forgot about. Not watering is not good. Last year I invested in a seedling heat mat and it worked quite well. I was able to leave the flat on the counter in the laundry room, where I actually saw it, and remembered to water it. Things were looking up! Then, apparently the next flat I used had a small hole in it. After a few days, I wasn't seeing much condensation build-up on the inside of the plastic dome. I lifted up the flat, and the mat was sitting in a puddle of water. Cold. Damn. I'm lucky I didn't burn the freakin' house down!
So, when I decided that this was the year I was going to make my seed-starting a success, I started looking at seedling mats again. They're danged expensive! A one-flat size mat is $30. And I had already decided that it wasn't big enough and needed one that would warm two flats. $50 bucks. Then I found this. I could make that! So, I gathered what I could, went to Home Depot for the rest (a piece of plexiglass and a sheet of foam), and got to building.
First, I built a small wooden box out of some thin, light weight wood I had. The piece of plexiglass was 18x24, so I made the box 17.5x23.5 to avoid last year's debacle with pooling water. I used wood glue and finishing nails to hold it all together.
|The finished box|
Next, I cut a piece of foam to fit the inside dimensions of the box.
Then, I cut the sides and glued all the the foam pieces to the inside of the box.
|I used clothespins to hold it all together|
Then, instead of using rope lights, I decided to use Christmas lights. I don't know why I thought of it, maybe because I've been stepping over THIS since Thanksgiving...
The broken strands of lights that have been sitting in a pile on the dining room floor since I decorated the tree. I was going to sit down, inspect each one, and replace the broken bulbs to make them work again. You can see that hasn't happened yet. One of the extra-long strands in the pile had about half its' lights working. The rest went in the trash.
|The finished box, on my kitchen counter|
I still needed to test the temperature, though. I had no idea how many Christmas lights I would need. So I set a thermometer on top of the box and kept watch.
|64 degrees! Yay!|
However, 15 minutes later this is what I found...
|80 degrees! Too hot!|
So I set up my little greenhouse flat and put the thermometer inside to get a truer reading of what the soil temperature will end up being.
|74 degrees - Just Right.|
And there you have it! A two-flat heat mat for $11 instead of $50. Gotta love it.