This photo was taken 10 days ago. I now have 4 shelves of salad greens on my outdoor shelves. The shelving unit is actually the innards of this portable greenhouse, bought in February 2016.
For growing salad greens on the shelves this spring and summer, I slid the plastic zip-up cover off of the shelf frame, and set the cover aside until fall rolls around. Because tall, narrow, and somewhat lightweight things tend to not stay upright in our gusty winds, here, I've secured this to the siding of our house with large hooks and bungie cords at the top and bottom of the unit. I did need to replace the bungie cords this season as the previous ones wore out. It's pretty secure against winds.
I'm growing the greens in the bottom halves of 1-gallon plastic milk jugs, the same "pots" I used indoors under lights this winter growing radish greens. I reused the soil from the radishes, stirring in fresh organic fertilizer specifically for greens to boost the nutrients for my little lettuce "patch".
I can add one more shelf of 2 rows of salad pots, when I have more empty milk jugs. That will give me 40 pots of lettuce, spinach, and parsley.
I have staggered the seed starting dates, so that we will have a continuous supply of fresh salads through spring and into summer. The lettuce in this photo should be ready for the salad bowl in about a week. I will begin more heat-tolerant greens in early June so we don't lose our salads altogether when the weather warms up in July and August.
Although 3 rows of pots will fit on these shelves, I've only set up 2 rows, as the back part of the shelves doesn't receive the amount of light needed. As it is, I rotate the pots from front to back and back to front once per week, to ensure all of the plants are getting enough sun.
Growing my lettuce vertically on shelves leaves the garden bed space free for larger plants, as well as keeps my lettuce out of the pathway of hungry slugs. In addition, growing vertically in this way has a much smaller footprint than growing 40 pots laid out side by side on the deck floor.
Besides, I like the look of my vertical lettuce patch on shelves. There's something visually appealing about the tidy little rows of pots lined up on shelves, one shelf above another.
