The Basics of Growing Micro Greens
Seed selection is an important initial step in planning. You may want to start with a few straightforward varieties or a professionally premixed selection of micro greens, then diversify later on. Johnny's currently offers two premixed options — our Mild Micro Mix, a balanced combination of mild brassicas, and our Spicy Micro Mix, a complement of sharper-tasting varieties — both precisely designed to produce a range of colors and textures with compatible growth rates.
Many micro green varieties are ready for harvest in two weeks, but depending upon variety and environmental conditions, that production cycle can be prolonged up to four weeks and beyond. With practice, sowing times can be coordinated to produce a mix of varieties ready for harvest at optimal size and flavor. In relation to growth rate, mustard and radish greens, for example, mature faster than beets, chard, or carrots. With trialing and detailed record-keeping, you can become adept at timing production.
(For further selection guidance, refer to our Micro Greens Comparison Chart, sorted for fast-growing [10–15 days] and slow-growing varieties [16–25 days], as well as leaf color, stem color, flavor, and texture.)
In order to get started growing micro greens, you will also need to calculate your space needs and gather a few supplies — many of which you may already have on hand — a sterile growing medium such as soilless mix, trays, domed lids, and a sheltered growing area. In addition, heating mats and lighting may be required for off-season production systems.
Seeds for micro greens are often sown into standard 1020 flats or 20-row seed flats containing 1–1½" of a light, sterile, soilless mix. When getting ready to sow, take seed size into account, as this will determine the best method of planting. Seeding densities should be thick enough to cover the flat but not to the point of inhibiting air flow. Both small and large seeds should be sown thickly, then gently tamped into the soil. Approximately 4–6 seeds per square inch is a good rule of thumb.
Small seeds can be covered with a layer of paper towels or finely sifted vermiculite. Large seeds should be covered with a light layer of the grow mix. Using a sifter or colander can be helpful.
Once the flats are sown, gently water with a slow, steady mist to avoid washing away the seeds. Cover the flats with a clear plastic domed lid to retain humidity and aid in germination. Remove the lid or ventilate during sunny, warm conditions. If using paper towels to cover the seed, gently remove the towels within just a few days. Most of the seed coats will adhere to the towels upon removal, which greatly facilitates the washing process.
Micro greens are most often grown in greenhouses or other protective structures due to the fragile nature of the product. Growing on raised platforms or tables eliminates frequent bending over to tend the plants. Provide sufficient air circulation with fans to prevent disease and mold issues. The flats of micro greens need to be kept moist but not overly wet. Many growers utilize bottom-watering methods to minimize soil splashing, which also produces a cleaner finished product.
Because of the one-cut nature of micro greens, succession planting is necessary to produce a steady supply of this crop. Sowing dates and quantities of seed sown should be based upon customer demand, delivery schedules, and varietal growth rates. As noted, different varieties grow at different rates. Keep records and modify your system as needed.
Growing micro greens off-season indoors or in a greenhouse requires additional attention. Lights, fans to circulate air, and heating mats are usually needed. Many plants respond differently to artificial light than they do to natural light. Take note of light duration, intensity, and distance from the crop, factors that will determine the growth rate and quality of your finished product. If the light source is positioned too far from the crop, stretching or leginess may occur. Crop color may appear washed-out when the light intensity is insufficient. Some growers find that fertilizing is needed to prevent yellowing of the micro greens. A soluble fertilizer in the mister or bottom feed water supply can resolve this. Producers should take care to avoid "off-flavors" that sometimes derive from fish-based production materials.
Micro greens are typically harvested with one set of true leaves, with the cotyledons still attached, at heights varying between 1–2". Each variety’s appearance and taste provide an indication of its optimal harvest period. Again, some trialing can be helpful.
Micro greens are tender and need to be handled with care. Harvest by cutting handfuls with scissors, or cut entire flats with an electric knife. Depending on your market requirements you may opt to cut the product directly into its final packaging, often a clear plastic clamshell or tote, for mixing and/or washing. Refrigeration is generally necessary to maintain freshness and quality after harvest. Packaging is selected to suit the intended primary end user, whether sold by individual serving size or in bulk, based on weight or volume.
Marketing Micro Greens
Although marketing is addressed last here, keeping it at the forefront of your priorities will benefit your chances of success. Before ramping up production, research your market to make sure you have the customer base. Explore potential micro greens customers in your expected distribution area; restaurants are the most common channels; however, specialty food stores and some farmers' markets also have demand. Plan to produce a few preliminary mixes, or set up an assortment of individual micro greens to offer as free samples, to develop your customer base. This approach can also be effective for introducing a new variety or line of produce to established customers.
If you're not already routinely asking your buyers and chefs for their input and feedback, add to your checklist, too, so you can continually modify and improve your product line. Customers stay more engaged when offered novel varieties and combinations, particularly when they're confident your products are consistently fresh and of the highest quality.
These are simple guidelines from Johnny's Research Team to help you get your micro greens program up and running. Produced efficiently and marketed successfully, micro greens can bring a whole new level of diversity to your operation. For additional information about year-round micro greens production, refer to the following resources.
- Read Johnny's Top Picks for Getting Started with Micro Greens »
- View a list of Johnny's Herb Varieties for Micro Greens »
- View a list of Johnny's Fast-Growing Micro Greens Varieties »
- View a list of Johnny's Slow-Growing Micro Greens Varieties »
- View a comprehensive list of All Johnny's Micro Greens »
- See Johnny's Micro Greens Comparison Chart (PDF) »
- PDF version of Johnny's Guide to Micro Greens Production (PDF) »
- Simple steps for transitioning from mixes to customized product to meet market needs — Customized Micro Greens »