Planting a 27-day salad box

I taught my "Growing Food on Rooftops" workshop at Brooklyn Public Library's Greenpoint Branch last Thursday, and encouraged people to plant cut-and-come-again salad greens in old salad containers. The idea behind cut-and-come-again is to grow vegetables (typically leafy greens) from which one harvests the young outer leaves. By harvesting before the plant begins to make seed, you are able to come back over and over to enjoy the fruits of your labor.


It's already August, and I know it feels soooo late in the season to be starting crops. But now is actually a great time to plant out a salad box and start seeds for cool weather crops—I'll talk about the latter in detail in a later post. The salad box I planted will be ready to harvest in a little under a month. 

To plant this salad box, I took the plastic container in which some baby kale from the grocery store came, washed it and poked about 8 holes in the bottom. I set the lid of the bin aside—I'll want this later. Next, I filled the container to the brim with an organic seed starting mix. Seed-starting mixes, by the way, contain a combination of soil medium, mycorrhizae and other soil amendments that create a nutrient-rich environment ideal for seedlings. I love seed-starting mixes because they are so packed with the nutrients seeds need and because they are usually quite light and airy, enabling plenty of water and oxygen to get to seeds. One mistake I see people making when they start seeds is to do so using top soil, or soil from a garden that hasn't been amended in any way. When watered these mediums get heavy and become the consistency of wet concrete. Seeds will drown and rot in that environment. Taking the time to buy or make a seed-specific blend is absolutely worth it. 

I filled the container to about half an inch below the brim with seed-starting mix. With a spray bottle of water I spritzed the surface of the soil until, looking through the sides of the container, I could see the color of the soil turn dark with moisture. Next I mixed a little over a quarter teaspoon each of Johnny's Seeds Ovations Greens mix (one of my favorite salad mixes), Hudson Valley Seed Library arugula and Baker Creek Heirloom Seed Company's Tronchuda kale. These are all organic seeds. I dispersed the seeds over the surface of the soil by grabbing a pinch and distributing it evenly, as if I were sprinkling seasoning over a pot of stew. I hope that makes sense ¯\_(ツ)_/¯

I then took a small handful of seed-starting mix and sprinkled that on top of the seeds. Not to bury them, but to lightly cover them and stop the seeds from being washed to the sides of the container when watered. The soil having settled over my seeds, I gave a nice, moderate spritzing with the water bottle. 

Going back to the lid I had set aside, I placed this under my planted-out salad container and set it in the sun. You want seeds to have as much sun as possible while germinating. I have a sunny window ledge on my fire escape, where I put most of the vegetables I grow at home, including my salad box. As the seeds germinate, I'll be vigilant about checking them in the morning and afternoon (especially on hot days) and spray them with water when the container feels especially light (indicating all water has evaporated/been absorbed), or when the soil looks dusty.

I should have fresh salad greens in one month!