Part 4: Growing Greens Indoors All Year
It's way easier than you might think...!
Reporting on my 2+ years of attempting to grow food indoors. Skeptical? I was too, but I ended up being pleasantly surprised at how easy it was.
Questions to contemplate:
How much space do you have?
How quickly do you want to harvest?
What’s your budget?
How much natural sunlight do you have access to in your space?
How much time do you want to spend each day growing food?
What do you like to eat?
I’ll summarize first the growing methods I’ve tried; then further down, I’ll make some recommendations based on the questions above.
Sprouts:
Love them. Easy to grow. Very nutritious -- especially broccoli and lentil sprouts.
Here’s a no-nonsense video demonstrating how simple they are to grow (courtesy of the Painted Spoon youtube channel):
Recommended materials: any mason jar + stainless steel mesh caps that don't rust. Here’s what I use: https://www.amazon.com/Rings-Screens-Inserts-Mason-Sprouting/dp/B09GXZ9VHP
Seeds: I buy mine from the good folks at Johnny’s Seeds. They also offered some helpful insight regarding the difference between sprouting seeds vs. microgreen seeds / regular planting seeds.
“Sprouting seeds and microgreen seeds do differ slightly. Mostly that sprouting seeds undergo more testing to ensure they are free from the presence of E.coli and salmonella bacteria. Sprouting seeds are also handled as a food product and stored as such because there is opportunity for folks to eat the seed casing. The sprout itself is still the entire contents of the seed. Seeds have all the energy and nutrients needed to mature to sprout stage, that is why no soil is needed to sprout seeds. Both type of seeds are selected to perform well to the harvest stage, so sprouting seeds may not perform well to the microgreen stage of harvest. I also would not advise growing microgreen seed as a sprouting seed because it does not go through the same testing and handling.”
So, can you use regular planting or microgreen seeds for sprouting? Yes, but it’s recommended to soak them in mild dishwashing liquid (e.g. Dr. Bronner’s) for 10 minutes followed by multiple rinses before letting them stand to drain.
If you’re sprouting beans, lentils, or sunflower seeds (unshelled), you can use the same ones you buy in the bulk section of grocery stores. They work perfectly fine. If you’re doing lentils, green or brown lentils are best.
Another cool thing: the price per 100 sprouting seeds is MUCH cheaper compared to the price for the same number of regular planting seeds, and you can still use sprouting seeds for planting! The germination rate may be slightly lower, but they’ll still grow into mature plants. It’s a great way to save money if you’re stocking up on seeds.
Seeds you’re not using yet should ideally be stored in a dark, dry place at temperatures between 35-40 degrees Fahrenheit, and at 40% or lower humidity. They can be stored in the refrigerator, but since fridges typically have higher humidity, they should be in an airtight container. You could also add a desiccant pack, just to be safe.
For the nutritionally nerdy, here are a couple worthwhile links:
Interview and Q&A with nutritional biochemist Dr. Jed Fahey (former professor at Johns Hopkins), including an in-depth discussion of the benefits of sulforaphane, which is found in broccoli sprouts. https://www.foundmyfitness.com/sprouting
Article summarizing the nutritional benefits of different foods as sprouts vs. microgreens. Main takeaway: broccoli, radish, and lentils offer the best nutrition as sprouts; radish, amaranths, and kale offer best nutrition as microgreens. Wojdyło et. al. (2020). Sprouts vs. microgreens as novel functional foods: Variation of nutritional and phytochemical profiles and their in vitro bioactive properties. Molecules, 25(20), 4648.a https://pdfs.semanticscholar.org/469c/3a3dc1e8ab79d1ecd904d1f6e017d84fc18d.pdf
Which leads us to…
Microgreens:
I found microgreens more complex and labor-intensive to grow. With sprouts you only need seeds and a jar, whereas microgreens need some kind of medium to grow on or in and different levels of light at different stages. I had fun watching all the little baby plants grow into shoots, and would definitely recommend trying microgreens at least a couple times. But in terms of the effort to yield ratio, I'd say they're more for novelty and adding fancy greens to salads—or for growing and selling, if you go that route. On the whole I think it's easier to sustain a quantity of food production with either sprouts or potted plants.
Here’s a basic video demonstrating how to grow microgreens (courtesy of the Life in a Pot youtube channel):
Covering the seeds with the top tray and then adding additional weight forces the initial sprouts (= the roots) to grow down into the soil, which helps support the greens as they grow upwards.
Here’s a handy chart showing fast vs. slow growing types:
Microgreens are usually harvested after the first “true leaves” appear, which is apparently when they have the best flavor + nutrition.
I like to stay away from plastic as much as possible, so I ended up using glass cooking dishes. (Can often be found at thrift stores.) These are cool because you can see all the roots snaking through the dirt.
For soil, a sterile growing medium is best. I like Jiffy’s Seed Starting Mix (OMRI listed), which you can get for $7 at Home Depot.
Another option for the growing medium, as mentioned in the video, is coconut coir. Many people seem to prefer coir because the harvested greens don’t need to be rinsed as much, the way they do when growing in dirt. You can also cut the greens closer to the coir compared to cutting in dirt, which gives a slightly higher yield.
I tried Terrafibre mats, which are hemp fiber (similar to coco coir), made in Canada. They work really well.
After harvesting, dirt, coco coir, and Terrafibre mats can all be composted.
Here’s a good video comparing microgreens grown with terrafibre mats vs. dirt (courtesy of the Small Space Growing youtube channel):
A third option is specially designed trays that have holes for the roots to grow down into water or water + liquid nutrients (example). I haven’t tried this but it looks relatively easy. (Most of these are plastic though, and I just have a weird thing about not using plastic, which is why I haven’t gone this route.)
One nice feature of the growing trays is that you can water underneath the plants instead of spraying directly on the leaves, which helps prevent leaf mold from forming. As a workaround for this when growing in soil, I poke holes in the dirt in the corners of the glass dishes, water directly into those holes, and then tip the dishes to ensure the water evenly distributes.
Once the baby leaves start to grow, the plants will need light in order for the leaves to turn green. Setting them in front of a window that gets decent natural light works fine. If natural light is limited—or you want to boost your greens—you can use a basic full spectrum grow light (lots of options on Amazon).
OR, if you’re growing in any kind of volume, you might want to consider a higher end grow light, such as the ones made by Spider Farmer or Mars Hydro (considered top of the line). (Both are also sold on Amazon.) The advantages to specialized grow lights are typically that they’re more efficient energy-wise, and give better coverage.
The type of artificial lighting you use does have a considerable impact on the growth rate and volume of the microgreens. Here’s a good video comparing low-end/diy vs. high end grow lights (courtesy of the You Can’t Eat the Grass youtube channel):
And to round this out, let’s talk about…
Regular ‘ole plants in pots: At the end of this discovery project, I've landed on growing just regular plants in soil. They take longer to grow, certainly, but most greens such as kale, chard, etc. are “cut and come again,” meaning you can harvest a few leaves and more leaves grow. There’s also just something about the abundance of harvesting multiple meals from one tiny seed that I find kind of mysterious and amazing…
Pots: I again try to stay away from plastic, and instead often use unglazed clay pots. I’ve also had good success with Smart Pot fabric pots, which are lighter and easier to reposition/transport, and are my one concession to growing plants in something plastic-adjacent. An important note: There are many different brands of fabric pots but they’re definitely not all created equal. Smart Pots are BPA-free and carefully tested to ensure the fibers are inert/won’t degrade over time and leech into the soil (see their FAQ). I’ve had good success finding second-hand Smart Pots on facebook marketplace. They can be washed and re-used very easily.
Temperature: some plants such as arugula thrive best with temps between 45-65 degrees Fahrenheit, whereas kale and chard do ok in higher temps. If you’re growing indoors and using high intensity grow lights, be aware that this will also increase the air temp above the plants. You may want to incorporate an air conditioner into your setup, depending on what you’re growing.
Pests: Mature plants attract pests, which seem to materialize out of the ether even in the middle of winter. My biggest issue so far with the plants has been fungus gnats, which don't really hurt the plant in the short term, but over time can damage the roots. They also multiply quickly and are super annoying. Happily, I found this video and learned about neem cake tea, which took care of them! (Courtesy of the Evermore: Eden Restored youtube channel):
I use the Eden Grow Max (OMRI listed) brand of neem pellets, which has worked well so far. Neem is great in that it’s not harmful to beneficial bugs and also nourishes the leaves and roots of the plant.
A groovy thing about potted plants is that as the weather starts to cool in the fall or warm in late spring, you can just take your outdoor potted greens indoors, or move your indoor pots outdoors. I’ve had plants continue to produce long after their typical season this way.
Also, potted plants give you the option of allowing the plant to grow to the point where it produces its own seeds! This way you can harvest, store, and use them to kick off your next generation of plants. The book The Seed Garden has a lot of great tips and helpful photos on how to do this.
Revisiting the questions from the beginning of this post:
How much space do you have?
Very little space: go for sprouts. Lots of space: take your pick or try them all!
How quickly do you want to harvest?
Sprouts are fastest (5-6 days), then microgreens (7-14 days), then potted plants (10-20+ days for baby greens, 30-50+ days for mature plants).
What’s your budget?
Sprouts are budget-friendly in that the materials are simple. Potted plants will give you higher yield per seed.
How much natural sunlight do you have access to in your space?
Low light: sprouts can be grown in room light, no special lighting required. Microgreens do best with either natural light or a grow light. Potted plants need the most light — either full sun or grow lights.
How much time do you want to spend each day growing food?
Potted plants require the least maintenance once they’re potted. Sprouts are pretty low-maintenance but need to be rinsed at least 2x/day. Microgreens are imho the highest maintenance due to the different conditions required for different growing phases.
What do you like to eat?
Probably the most important question. What do you enjoy eating enough that it’s worth putting the time, energy, and money into growing it…?
Other options to consider once you get into indoor growing:
Grow tents/kits: thanks largely to the legalization of growing weed for recreational use in many states, there are many different grow tents available, including some that come in kits complete with lights, shelves, and ventilation (example). These can be useful if you want to control the humidity of the growing space. Most tents also have reflective walls to maximize light diffusion.
Hydroponic growing: I’m definitely curious about hydroponic and am planning to try this as part of the next phase of my indoor growing adventure. The two main options are 1) the Kratky method, which involves roots growing in still water + nutrients, and 2) (re)circulating systems that use a water pump.
A note about hydroponic growing for newbies: in most states that have legalized recreational weed growing, it’s pretty easy to find hydroponic garden stores, and there’s usually at least one person working in the store who can advise on growing vegetables this way. :)
All-in-one hydroponic systems: these are becoming more and more common. A basic version is AeroGarden, and a higher-end version is Gardyn. I’ve heard good and bad things about these types of systems: a pro is that after initial setup, they’re very easy to use, in that they often come with ready-made soil pods complete with seeds that you just pop into the baskets and they’re ready to grow. Many systems, though, are designed to be used only with the seed pods produced by the system’s manufacturer. Some require a monthly subscription. Based on what I can tell, it also may be more difficult to find organic seed pods with some systems, if that’s your preference.
Here endeth my report on the first two years. I learn new things every day so at some point they’ll probably be a part 2!
Previously on The Thoughtful Prepper...