Johnny's Trial Greenhouse in Albion, Maine

Guide to Year-Round Micro Greens Production

Planning • Sowing • Production • Harvesting • Marketing

Micro greens are the seedlings of edible vegetables and herbs that are harvested when quite young, generally at the first-true-leaf stage of growth but in some cases at the seed-leaf stage.

Micro greens are trendy, vibrant, nutritious, and versatile, adding panache to nearly any culinary presentation — gourmet salads, sprinkled over entreés, or used as a garnish.

View All Our Micro Green Varieties

Venturing into micro greens production offers a grower the opportunity to expand existing markets and open new ones. Micro green varieties can be marketed as individual components or in signature blends, combining different flavors, colors, and textures. When grown in a greenhouse with supplemental heat or indoors under lights, micro greens can be produced year-round, even at high latitudes through the depths of winter. In addition to their versatility and potential profitability, they are nutrient-dense, intensely flavorful, and simply beautiful.

While micro greens are relatively easy and quick to grow, and start-up costs relatively low, there are some important points to micro greens production to know up front. Here are some of the basics of planning, sowing, production, harvesting, and marketing, to help get you started.

Micro Greens Comparison Chart
Tray of 5 varieties of micro greens, selected for similar growth rate, in a range of colors, flavors, and textures
Sowing dates can be coordinated to produce a mix of varieties, all ready for harvest at once, at ideal size.

View Our Micro Greens Comparison Chart

Seed selection is a key component to production strategy. 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 are precisely formulated to produce a range of colors, flavors, and textures with compatible growth rates.

Micro greens have a quick turnaround time, but there are differences in growth rate between different types and varieties. The majority of vegetable varieties grown as micro greens are ready for harvest in about 2 weeks, but the brassicas mustard and radish have a faster growth rate and therefore mature faster than beets, chard, or carrots. Herbs grown as micro greens, on the other hand, tend to be comparatively slow-growing, maturing in 16–25 days. Depending upon types, varieties, and environmental conditions, a production cycle can be prolonged up to 4 weeks and beyond.

Use our Micro Greens Comparison Chart to become more familiar with the fast-growing and slow-growing groups, along with other distinguishing features, and to help you choose varieties to grow concurrently. With practice, sowing times can be coordinated to produce a mix of varieties, all ready for harvest at once, at optimal size and flavor. With some trialing, good record-keeping, and repetition, a grower can become very adept at production-cycle timing.

Equipment and space are two additional factors you'll need to consider in the planning phase. Before you get set up, calculate how much space you have or will need, and gather together a few supplies — many of which you may already have on hand: a sterile growing medium such as soilless mix; trays and domed lids; and a sheltered growing area. In addition, you may require heating mats, lighting, and fans to provide favorable environmental growing conditions.

Calculate Seed Needed & Potential Yield  Micro Greens Production
Standard 1020 flats or 20-row flats work well for micro greens production

Watch our video for tips on correct seeding density and yield.

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Micro greens are often sown into standard 1020 flats or 20-row seed flats filled with a light, sterile, soilless mix to a depth of 1–1½". 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. As a rule of thumb, sow small seeds at a density of approximately 10–12 seeds per square inch of tray surface, and larger or medium-sized seeds at a density of 6–8 seeds per square inch.

Small seeds can be covered with a layer of paper towels, or finely sifted vermiculite, or a small amount of soilless mix. Large seeds should be covered with a light layer of the grow mix. Sifters and colanders can be used to help to sort seeds by size.

Once the flats are sown, gently water them; use a slow, steady mist to avoid washing away the seeds. Cover the flats with either a clear or white plastic dome to retain humidity and aid in germination. Take care to 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.

Tabletop setup
Simple waist-high tabletop setup

Build a versatile Hanging Micro Greens & Seedling Bench for your greenhouse, hoophouse, or high tunnel with our Parts & Construction Cost Calculator and detailed Construction Guide.

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Micro greens are usually grown in greenhouses or other protective structures due to the fragile nature of the product. Growing on hanging benches, raised platforms, or tables eliminates frequent bending over to tend the plants. Sufficient air circulation can be provided with fans to prevent disease and mold issues. The flats of micro greens need to be kept moist but not overly wet. Many growers use bottom-watering methods to minimize soil splashing, which also helps to produce 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 and resources; 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, wavelength, and 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 prevent any "off-flavors" that can at times be derived 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 and note-taking 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, such as a clear plastic clamshell or tote, for mixing and/or washing. Refrigeration is generally necessary to maintain post harvest freshness and quality. Packaging can be selected according to the primary end-users in your market, whether sold in an individual-serving size or in bulk, based on weight or volume.

Micros packaged in perforated bags and clamshells
Micros can be packed in micro-perforated food-grade bags, clamshells, or delivered to market in the trays they're grown in.

Although addressed last in this article, placing market research at the top of your priorities will benefit your chances of success. Before you ramp up production, explore your market opportunities, to be sure you have a customer base. Contact potential micro greens customers in your projected distribution area — restaurants are the most common channels, but specialty food stores and some farmers' markets may also have demand. Plan to produce a few preliminary mixes, or set up an assortment of individual micro greens samples to offer free of charge, to develop your customer base. This approach can also be effective when introducing a new variety or line of produce to established customers.

If you're not already routinely surveying your buyers and chefs for input and feedback, add that to your checklist, too, so you can modify and improve your product line over time. Customers stay more engaged when offered novel varieties and combinations, especially when confident of the freshness and quality of your product.