Seriously, it’s not that hard to grow salad all winter long. Enjoy fresh, tender, delicious salad greens indoors in recycled plastic containers under a couple of inexpensive fluorescent shop lights. It’s fun to grow edible plants—plus, no weeds or pests! Here’s how to use grow lights for salad in winter.
Growing Lettuce Under Lights
Last year, I purchased grow lights to start seedings in early spring. They’ve never been used in winter so growing salad in winter is a perfect match!
If you don’t have grow lights, you just need cheap florescent shop lights. My fixture is suspended by chains and S-hooks from the ceiling of my living-room alcove. (You could also put the grow lights in an upstairs bedroom since heat rises.)
It is not necessary to invest in the very intense lighting systems that hydroponic growers use, because vegetable and herb seedlings live indoors for but a few short weeks, and regular florescent lights are ample for their needs. Besides, once seedlings are up and growing, gradually exposing them to more sunlight is the best way to prepare them for life in the garden.
Ideally, you want the light to be less than 2 inches from the tops of plants, but some seedlings gain height faster than others. Raising the slower growers by placing them atop books or boxes is often the easiest way to get them closer to the light they crave.
For planting containers, I used some of the recycled polystyrene (both foam and transparent) containers I collect for starting my spring transplants, filling them with a mixture of half soilless sterile potting soil suitable for seeds and half compost.
Photo: Margaret Boyles
Which Salad Greens To Plant?
The simple answer: almost any type of salad or cooking greens—the faster-growing the better—and leafy herbs.
During my first experiments, I mixed together seeds left over from my spring–summer garden, dividing them into three categories with similar germination and growth habits:
- Oak-leaf lettuce and various leaf lettuces work well for cut-and-come-again harvesting where you can remove a few leaves every week, extending production over a longer period:
- Kale, arugula, and leafy Asian brassicas (bok choi, mizuna, tatsoi, etc.)
- Spinach, chard, and beets (for greens).
- Arugula is always good to add a delicious flavor to salad mixes.
If you’re buying new seeds for winter planting, I suggest one of the fast-growing mesclun or braising mixes (also called stir-fry mixes) sold by most seed companies.
I scattered the seeds thickly across the soil surface, covered them with a bit of compost, and watered them well with a small watering can.
Credit: Margaret Boyles
Care and Harvest
Once the seeds germinated, I turned the lights on when I got up each morning and shut them off around supper time. I watered them every couple of days, when the top of the planting medium felt dry. Every week to 10 days, I watered with a weak solution of seaweed and fish emulsion (available at garden stores).
It’s important to keep the seedlings well watered and use high-quality compost or admendments to supply ample nutrients.
Equally important is thinning out the plants. I started thinning the plants as soon as they’d developed two or three sets of leaves, about three weeks after germination. I cut out any plants that were closer than an inch apart, snipping the plants just above soil level (to avoid disturbing neighboring seedlings), rinsing them, and tossing them into soups and cabbage salads.
As the plants grew bigger, I harvested the outer leaves and left the rest to grow. Alternatively, you can clip greens from throughout the whole container with fingernail scissors, making sure to leave the growing tips to produce another crop.
Be sure to raise your lights so that the plants do not get scorched. As a general guide, lights should be kept 4 inches above the highest leaf.
After 5 weeks of growth, six to eight containers of greens began producing robust, two-person salads three or four times a week for about 6 weeks, as well as quite a few handfuls of greens to toss into our frequent winter soups.
Photo: Margaret Boyles
By the way, producing winter salad greens under lights makes a wonderful project for children of any age. Great science project possibilities, too.
Plus, there aren’t any weeds or critters eating your greens!
The alcove where I keep my containers is also home to my stationary bike, which I ride almost every day or evening all winter long. Good food and good exercise: What a combo!