Okay, fluorescent bulbs aren’t exactly rustic. But for those of us transitioning to a life on the land, this may be your only alternative to a greenhouse. Some plants, like tomatoes, have to be started indoors unless you only want a single fruit somewhere in late August. Others, like cabbage, can be started indoors to give you a spring and fall harvest. Whatever the case may be, it’s not always financially feasible to construct a well-insulated greenhouse. So lights are a great alternative.
The first rule of growing under lights is not to listen to people trying to sell you expensive bulbs meant for growing plants. I have no doubt that these work, but at $30 a bulb, they can keep them. Instead, go to your local hardware store and pick-up a simple hanging light fixture that fits tube fluorescent bulbs.
You will need one at least two bulbs wide, but four or more is better. As for length, that all depends on how much room you have to work with, but make sure you rig the thing up so that you can raise and lower it as the plants grow or you put new seedlings in. A couple of slip knots should do the trick.
Next, you want to buy an equal number of “cool” and “warm” colored bulbs. Each of these bulbs puts off a different wavelength of light. The sun puts out these, everything in between and beyond, but something in the 5000K area and another in the 3000K area should be fine. The more extreme you can go on either end the better.
Unfortunately, I didn’t know how much of an issue this was until my plants refused to grow past 1 inch last year. Lesson learned: don’t just buy two cool colored bulbs. And if you have four bulbs, make sure that you alternate between the cool and the warm colored bulbs for maximum coverage.
A cheap timer from Home Depot keeps you from having to turn the thing off every night and on every morning. Give your plants a good 12 hours of artificial sunlight each day.Once you have your lighting rig set-up, you can go about planting. Go ahead and make fun of me, but I love the Jiffy starter kits with the little dehydrated peat tablets. Just add water and presto! You’ve got a self-contained ball of starter soil for your seedlings.
Tear open the top and fluff it up a little with a fork once the pots are fully hydrated. Then go about planting 3 seeds per pot. Don’t forget to label or you’ll never remember which tomatoes were paste and which were brandywine until mid-July. Then cover with the nifty little plastic greenhouse and lower the lighting rig.
At this stage, you want to keep the lights about an inch above the plant leaves. In my experience, tomato plants that are allowed to get too close to the lights get scorched (not by the heat, because this is minimal, but by the light itself). You don’t want to move the lights too high up because then your plants won’t grow as well. It’s a balancing act.
More issues arise as brassicas and tomatoes tower over your tender lettuces and herbs. You can help alleviate some of the stress by plucking out all but the strongest sprouts in each pot. However, once survival of the fittest sets in, it’s really time to start thinking about giving your plants some lebensraum.
Tomatoes should get their own larger pots, where they will wait until the last frost.
1 Seed Packet = $2.00. That’s the price of one plant at the garden outlet.
The brassicas (cauliflower, broccoli, Brussels sprouts, etc.) need to get hardened off and planted in the ground to get in that much-coveted spring crop. I recommend taking everything out of the trays except the brassicas and lettuce and giving it its own pot or a separate tray. Then, take the Jiffy tray with just the cold-hardy plants and start setting it outside. Start with one hour, and then work your way up to a full day by increasing their time out there one hour a day. If you don’t do this, your plants will shrivel and fail to thrive when you finally do plant them. And to give them a little extra protection, it doesn’t hurt to put them in a mini-hoop greenhouse.
Another good idea is to plant everything in succession. Start another Jiffy two weeks later, so that you get a consistent harvest rather than everything at once.
This obviously becomes difficult with older plants taking up more of that premium space under the lights, but do the best you can, and have hope, because one day, you’ll have a big, compost-heated greenhouse, and you’ll never have to worry about lights again (run-on intended).
So… Little… Space… Yes, I resorted to an incadescent for a little extra coverage towards the back. This works (kinda), but it wastes electricity and doesn’t really cover the cool end of the spectrum.
Have you tried growing under lights before? Is this your first year? Share your thoughts, tips, and stories below! We’re still learning ourselves, so advice is always appreciated.