Microgreens are rapidly emerging as a value added ingredient in salads, sandwiches, as a natural spice, or just to give the plate and the palate a little extra "kick". There are claims that they are higher in vitamin, Lutein, and many other nutrients, but the most promising article comes from WebMDwhich at least tells us that nutritionists need to continue looking at microgreens for their nutritional value.
Microgreen's short turnaround from seeding to harvest (sometimes as few as 10 days) allows for a great opportunity to learn systems quickly without a lot of investment. The other benefit is that it can operate year-round no matter where you live. Finally, you can turn your money around faster than just about any crop out there and if the market "gets it", there can be quite a lot of cash to be made.
So let’s keep it simple and look at what I call a series of "cheat sheet" ideas to get you up and running with a microgreen project! We'll go in depth on each of these topics. You will also read about our favorite microgreens that can be grown by any beginner.
Let’s begin by identifying just what a microgreen is. Growing immature seedlings can be pretty much grouped into three categories:
Sprouts –sprouts are defined as plants that have just sprouted their hypocotyl and the seed is still on the majority of the sprouts to be harvested.
Microgreens – microgreens are harvested at the first true leaf stage.
Baby Salads – this would be the stage the plants develop to if left to grow in the media for a couple weeks (sometimes longer) past the microgreen stage. As the name implies, they resemble a "baby" size of the full grown plant. *picture source
There are literally dozens of plants that can be grown as microgreens. When deciding which ones to grow, you should start by growing the easy ones, and decide which media they grow best in. Here’s a very general list of relative ease of growing for several of the microgreens:
Generally speaking, growing media is broken down into three primary categories:
Soilbased Use a planting mix which drains well, is free of clumps and stones, and doesn’t compact easily. Since you are harvesting the crop at about 1-3” in height, it’s not critical to have a lot of nutrients in the soil mix, so adding any nutrients should be done conservatively. You’ll want to keep the surface of the soil damp, but in many cases, keeping the soil too wet can lead to trouble with micros.
Any microgreen can be grown in soil, but that doesn’t mean it’s the best choice. Low growing crops like basil, for example, end up pretty messy at harvest. The closer you can harvest your microgreens to the media while keeping it clean, the better.
Soil-less media is comprised of different non-soil mixes. Coco coir, blends of vermiculite and/or perlite with an organic amendment, or hydroponic lava rock are examples of soil-less media. They can be leveled and lightly firmed so you can have a clean surface which is important at harvest time. This is a nice compromise choice between soil and hydroponic because the surface of the soil is cleaner than a soil media.
Hydroponic methods with microgreens at the beginner level is very simple, clean, and easy. It involves the use of a growing ‘pad’ which absorbs and retains water so as to keep the germinating seeds and emerging greens continually moist. When done correctly, your crop will be easier to harvest, you can cut right to the growing surface or even pull the crop right out of the pad and trim off the seeds and roots, making for a much easier harvesting process.
As mentioned earlier, all microgreens will grow in soil and soil-less media. Some crops are recommended NOT to be grown hydroponically. A rule of thumb is the large seeds should be grown in soil or soil-less media. This is because they need to be covered with a small layer of soil in order for the seed coat to shed itself from the emerging first set of leaves.
Examples include: Beets, Chard, Buckwheat, Cilantro, Pea, Sorrel (Microherb), Sunflower
Management of lighting is very important with most microgreens, but pretty simple to manage. For many micros, it's imperative to provide a ‘stacking’ period for the first few days. In most cases, this is a period of about 4-5 days after seeding. This will help maintain high humidity in and around the media to help your seeds germinate evenly. This period of imbibition (seeds swelling with water) is very important.
Basic Blackout Dome using an empty tray flipped over on top of the seeded tray. Keep the lid moist, mist the seed and media twice a day, maintain a high humidity environment. Note that most seeds don't need a blackout, but rather benefit from stacking for an initial period.
After 4-5 days, the crop is ready to accept light. In some crops, you can strengthen the roots by flipping the blackout dome over and setting it right on top of the emerging crop for a day.
If the room in which you’re growing the microgreens has good sunlight, you may need a minimal amount of supplemental light. Some micros require more light, some not as much…your best guide is to read up on the crop you’re choosing to grow. In all cases, remember you only need to get the crop beginning to make true leaves. If the emerging crop is ‘leggy’ it needs more light. If growing in racks stacked, then supplemental light will be needed for those shelves that do not have access to natural light. If the leaves exhibit spots, your light is probably too close.
A basic inexpensive method of accomplishing this is to use (2) 48" LED light bars per shelf occupied by 10”X20” flat& microgreen trays. LED lights provide an efficient means of providing a full spectrum of light to microgreens, and come in many shapes, sizes, and prices.
For the beginner, use what you have around the house, shop lights, clamp on’s with LED bulbs in combination with incandescent light, pay attention to your plants, and they’ll tell you how you’re doing.
Most microgreens prefer a room temperature of about 70° F…give or take. As you select your microgreens, your supplier should have this information along with other growing tips to consider. Some micros like Cilantro, prefer soil temps a bit cooler. Use a heat mat if your ambient temperatures are going to be too low.
Pre-soakingof the seed is recommended with some microgreens. When pre-soaking is recommended, it’s very important to follow the recommended duration of soak. Microgreens that should be pre-soaked are sunflower, pea, beets, buckwheat, chard, corn shoots to name a few. (again, typically to be grown in soil or soil-less media, and larger seed densities)
In most cases, especially municipal water sources, your water will be too high in pH. Use a pH test kit that will test from pH 4 – pH 8 (at least). Ideal pH of microgreen water is about 6.0. Most municipal water systems will have a pH around 7.0. A good guide when using lemon juice to acidify, is 2 teaspoons of lemon juice per gallon of water. If using other forms of acidifiers, follow guidelines.
“Keep it moist”.. is a good rule of thumb from seed to emergence. Using a mister allows you to accomplish this. Watering a soil medium can be tricky to keep splashed soil off the leaves. Watering a hydroponic pad is simple..you lift the pad, pour in water enough to come to the tops of the ridges in the bottom of the tray, make sure it’s distributed across the entire tray (front to back and side to side) and that’s it! You’ll find that you’ll water more as the roots develop so as to always keep the media moist. (note: some soil crops like a bit drier soil surface so refer to the recommendations that come with the seed)
It’s usually best to buy only enough seed that you’ll use up in your first few plantings. If you do have seed to store, keep it cool, dry, and dark; and leave it in the package sealed tight. A general rule of thumb is to never have more than a years supply.
You can actually get started playing with microgreens with some Tupperware™ containers or equivalent, but assuming you want to try it in a fairly serious manner, you’ll want to acquire the following basic materials:
Microgreen trays - the best way to start growing microgreens. If you’re growing hydroponically with grow mats, they should not have holes in the bottom. If growing in a soil media, you don’t need drain holes, but they would generally be good to have. Especially if you can insert the perforated tray over another tray which you can add water so that the water will move up through the soil via capillary action. You may still need to mist over the top of the soil to keep the seed zone moist, but once the crop starts to root, it’s surprising how deep they will go for water, especially the ‘soil’ crops noted above.
Quality water - tap water usually isn't the best, but you can try it. If you have a good water filter, use that. Rainwater is what we use at our farm.
Soil media, Soilless Media or Growing Padsif you intend to grow hydroponically - again, just depends on which micro you are growing.
Misterso as to keep your germinating seeds moist and water the early emerging crop.
Fertilizer? Not needed for micros, so don't worry about this.
Lights – as mentioned above, you really don’t need to go crazy with lights until you know you’re enjoying your new hobby or budding business, then go from there.
Harvestingyour microgreens is pretty simple. All you need is a sharp set of scissors that can cut as close to the growing media as possible. With some greens, you can just pull them out of the media and trim off the roots and seeds at the base. You should lay out the greens and pick out any remaining seeds and shake off any soil or other impurities. If you’re not going to consume the microgreens right away, washing is not recommended. If watering is needed at all, do so just before serving them. It’s good to have a salad spinner to remove as much moisture as possible when washing, then lay out on paper towels to air dry for a bit. Each is a bit different- some can withstand a lot of handling (sunflowers), some very little (basil)…the idea is to handle them as gingerly as possible so they don’t become ‘mush’.
YES! You can absolutely sell it! Talk to a local restaurant, some friends, or the corner store up the street and you might find people LOVE microgreens…and if they don’t know what they are, drop off a few clamshells once you get going - and they soon will. The best microgreen to tease with is by far, the Sunflower. They are a snack that kids and adults love! If you’re looking to sell them as salad or sandwich ingredients, try Arugula, Broccoli, and Kale. They’re all pretty easy to grow and have a great blend of flavors by themselves, or in a mix. Stop in at your local retail grocery store and make notes of what they’re selling their microgreens for. (don’t confuse microgreens with baby salads)… survey the internet for suppliers in your area to find out their prices.
What you have that nobody else is providing your market, is FRESHNESS. Microgreens have surprisingly good storage lives in clamshells and refrigeration, but there’s just nothing like same day fresh.
The one consideration that will cause failure at microgreens as an enterprise is the lack of attention. Think of it like a dairy farm..they have to tend to their critters twice a day (at least) every day of the year. If you skip one visit, and especially one day, you will notice because they will show you how much you were missed!
For more advanced information on running a microgreens business, check out our course on the Urban Farm Academy!