Once again, our broccoli seeds didn't need near the 7-10 days predicted on the seed packet to sprout. Within about 3-4 days of planting, several of them had already popped up out of the starting medium. When that happened, we turned off the heat mat and needed to add light. There is a window nearby, but at this time of year in Iowa there isn't near enough sunlight. When that happens, the seedlings literally have to reach for the light, growing tall and spindly.To augment the natural light, we decided to rebuild our grow light from last year.
If you haven't already seen it, the grow light we built is a simple PVC pipe structure. Anyone can build one just like it with minimal tools and a few dollars expenditure of pipe. Here are all the pieces laid out on the floor.
We have three pieces of 1" PVC pipe that are just a bit longer than our light fixture, vertical pieces a few feet long to suspend the light, and two side assemblies that gave us enough width to accommodate seed-starting trays. Those were just made of two shorter pieces joined at a T-fitting. The only slightly tricky part was cutting the pipe; we borrowed a special pipe cutting tool from a friend, but it could have been done with a saw, too.
Here's the grow light frame all put together. We simply pushed the lengths of pipe into fittings (6 elbows and 2 tees) so it can easily disassemble for storage. The top piece of pipe has a couple hooks screwed into it at the right spacing to match the chains from the light fixture.
Our light fixture is a regular 4 foot T8 fluorescent hanging shop light. It holds two light bulbs, and if you really wanted to go nuts, you could buy special (i.e. expensive) full spectrum bulbs designed for growing plants. But you can achieve almost the same effect by using one "warm" and one "cool" white light bulb. This gives the plants nearly all of the light spectrum that they actually use, and doesn't cost a fortune. For just starting seeds, it's a good way to go.
The light should be hung just above the plants, again to prevent them from having to reach for it. Since our light is on a chain, we can raise or lower it by hooking different links to the top bar. These babies need a lot of light, so rather than relying on our memories to turn the light on and off, we've got it plugged into a basic timer to provide 16 hours of light a day. All that leaves us to do is keep the little broccoli plants well watered and they should be fine until we need to transplant them.
For now, the plants seem to be doing pretty well! It's a long way from edible, but it's a start!