How to Grow Microgreens: Step-by-Step for Beginners

You can grow microgreens at home in 7 to 21 days with a shallow tray, a lightweight growing medium, seed sold for microgreens, water and a bright spot. Penn State Extension puts the whole cycle at “as little as seven and up to 21 days from seeding to harvest, depending on the environment.” That makes microgreens one of the fastest crops you can raise indoors, and a tray fits on a kitchen counter or a windowsill. This guide walks through the full method in order, then links to a short guide for each stage so you can go deeper wherever you like.

Seed to harvest

7 to 21 days

Tray

Shallow, with drainage holes

Seed per 10 x 20 tray

10 to 15 g (PSU)

Light

Bright window or 16 to 18 h of light

What you need

Everything on the list is simple to find, and most of it you may already own.

• A shallow tray with drainage holes. Penn State’s main advice is to use food-suitable material that is clean and has drainage holes. Standard 1020 greenhouse trays and 10- or 20-row seed trays are common, and Utah State adds that pie tins, takeout trays and other repurposed containers also work. Clemson says to wash recycled containers with soap and water, and Oregon State notes that holes can be punched with a nail.
• A growing medium. Seed-starting mix, pre-moistened coconut coir or a hydroponic grow mat all work (USU). Penn State also names seeding mats. See growing medium for microgreens and microgreens without soil.
• Seed labeled for microgreens. Clemson says to use seed labeled for microgreens or marked “untreated,” and Penn State adds that organic seed is a good option. Keep the seed in a dry, sealed container, dated, and cool until you use it.
• Clean water. Penn State recommends clean water for soaking, rinsing and irrigation.
• Light. A bright window works, and grow lights make growth even. See grow lights for microgreens.
• Clean scissors or a sharp knife for harvest.

The method in 8 steps

1. Start clean. Wash the tray, use fresh water and open a fresh bag of microgreen seed. A clean start sets up every step that follows.
2. Fill the tray with medium. Spread a lightweight medium evenly across the tray. Moisten potting soil or coir first (Clemson, USU); coir should feel like a wrung-out sponge.
3. Soak large seed if the variety calls for it. Pea and sunflower benefit from a 6 to 12 hour soak (UMD, USU). Radish, broccoli, kale and arugula go in dry.
4. Sow thickly and evenly. Microgreens are sown more densely than crops grown to full size (UMD). Use 10 to 15 g per standard 10 x 20 tray as a starting point (PSU), then adjust for the variety with the seed calculator.
5. Cover and keep it dark for the first days. The blackout stage is where seeds germinate. Read the blackout method for covered days by variety.
6. Uncover and give light. Move the tray under a bright window or grow light. UMD says about 16 hours of light a day; USU says 18 hours on and 6 off.
7. Water from the bottom. Set the tray in shallow water until the medium is wet, then lift it out and let it drain (PSU). See watering microgreens.
8. Cut when the first true leaves show. Use clean scissors and cut just above the medium. Then store them cold and dark for the longest freshness.

Step 1 and 2: tray and medium

Because microgreens are cut at the seedling stage, the tray never needs deep soil. A shallow, drained tray with an even layer of lightweight medium gives roots enough room for a 7 to 21 day crop. UMD recommends any lightweight soilless mix in the container and describes garden soil as too dense for trays indoors.

Sources name several good media, and you can pick the one that suits your kitchen. A soilless seed-starting mix is easy to find. Coconut coir is lightweight and holds moisture once pre-moistened. Hydroponic grow mats are tidy, and Penn State notes that harvested microgreens are cleaner from seeding mats than from potting soil. Oregon State and Clemson both describe moistened potting soil as a workable choice too. The growing medium guide compares them side by side.

Step 3 and 4: seed and sowing

Seed for microgreens is sown thickly. Penn State’s rule of thumb is 2 seeds per square inch for large seed up to 12 for small seed, with lower rates in summer than in winter and for larger seed than smaller. Its own tray rate is 10 to 15 grams on a standard 12 x 20 inch 10-row tray.

Utah State lists a rate for each variety, which is handy once you move past the first tray.

Source: Utah State University Extension, with UMD for the cilantro soak. If you are new to this, radish, arugula and kale give a quick first harvest, while pea shoots and sunflower are popular for their larger leaves and stems.

Spread seed evenly over the surface. Penn State says it is not necessary, and could be better, to leave the seed uncovered by medium so the shoots stay clean. Press gently so seed makes contact with the medium.

Step 5: the blackout stage

For the first part of germination the tray is kept dark. Utah State places a second 1020 tray directly on top, with a weight such as a piece of plywood cut to fit, which helps the seeds stay in contact with the medium while the roots push down. For the second half of the dark period, the top tray is lifted off and turned over so it forms a roof without touching the seeds. Penn State says to keep seeds in the dark for a few days, and Clemson and UMD describe using a clear cover to hold warmth and moisture. Both approaches work, and the blackout method guide shows each one.

Germination speed depends on warmth. UMD says microgreens germinate and grow well at 70 to 75 F, and the cabbage family (broccoli, radish, kale, arugula) can germinate in about 36 hours at 72 F.

Step 6: light and temperature

Once the cover is off, microgreens are a low-light crop (Penn State puts them below 20 mol/m2/day DLI). Cornell says they do great indoors without special light requirements, and Oregon State says a bright window does the job while fluorescent lights give the most even growth. If you use lights, the sources give two schedules: USU runs them 18 hours and then dark for 6, and UMD aims for about 16 hours of total light a day. Details are in grow lights for microgreens, and if you prefer natural light see microgreens on a windowsill.

Temperature guidance varies a little by source, so treat it as a comfortable range. UMD recommends 70 to 75 F. Utah State holds 74 F for germination, 72 F with the lights on and 68 F with them off. Penn State gives 60 to 75 F for soil and 60 to 70 F for air. Purdue suggests 68 to 72 F and advises keeping trays away from HVAC vents and the temperature swings near windows. Keeping a tray in the 68 to 75 F zone satisfies all of these.

Step 7: watering and airflow

Watering is the step most worth getting right, and bottom watering makes it easy. Penn State and Cornell both recommend it. Place the tray in a tub with shallow water, take it out once the medium is wet, and let it drain. Cornell says to start once the seeds have sprouted. Before that, and as an alternative, a spray bottle keeps the medium damp (Oregon State, Clemson). Water when the tray needs it and let excess drain (PSU).

Air movement helps. UMD suggests a gentle breeze from a nearby fan and venting any tray covers from time to time, and Penn State says opening a window now and then keeps moisture in balance. More in watering microgreens.

Step 8: harvest

Microgreens are ready when the first true leaves begin to show, and Utah State says “or sooner.” Purdue puts most crops at 2 to 4 inches tall, with pea shoots cut taller, and UMD describes 2 to 3 inches tall at 7 to 21 days. Cut the stems just above the medium with clean, sharp scissors or a knife and leave the roots behind (Penn State). Penn State growers report that scissors give a longer post-harvest life than electric clippers and knives. The harvesting guide has the full routine, and the harvest planner turns your sow date into a cut date.

Choosing your first variety

Every variety follows the same eight steps, so the choice comes down to flavor, timing and how much seed you want to use. Utah State describes the flavors: sweet pea for pea shoots, nutty and sweet for sunflower, nutty and spicy for radish, mild broccoli for broccoli, peppery for arugula and intense basil for basil. For speed, arugula (6 to 8 days) and the 8 to 12 day group of radish, broccoli and kale lead the table above. For a first tray in a window with modest light, UMD notes that arugula and mustard tolerate less-than-ideal light. Basil and cilantro are slower growing (UMD), which makes them a rewarding second project once you have a rhythm. If you are curious about what each variety offers, the sourced figures are on the microgreens nutrition page.

A mixed shelf is easy to run: one quick brassica, one larger-seeded tray of pea or sunflower, and later an herb. Each has its own covered days and cut date, and the harvest planner keeps them straight.

After the harvest: the next tray

A cut tray is a finished crop. Oregon State says microgreens do not regrow after cutting, so refill the tray with fresh medium and sow new seed (Clemson). UMD allows a 50:50 mix of old and new medium, and Penn State notes that fresh medium for each cycle is the best way to start. Oregon State also suggests succession planting: start just enough for two people to eat, then sow another tray every few days so there is always something ready.

For storage, Penn State reports that dark storage at 41 F can extend shelf life to 10 to 14 days, compared with 2 to 4 days at room conditions, and Clemson says to keep microgreens in a clean plastic bag in the refrigerator. See storing microgreens.

A simple weekly rhythm

Oregon State suggests starting just enough for two people to eat and then planting more every few days. A tray sown on Monday and a second tray sown on Thursday will be ready a few days apart. By the time the first tray is cut and stored, the second is just coming out of its blackout. Quick varieties such as arugula (6 to 8 days) and radish (8 to 12 days) suit a short rhythm, while slower herbs like basil (12 to 16 days) and cilantro (21 to 28 days) can run alongside as longer projects. The growing microgreens at home guide lays out a weekly table, and the seed calculator gives the amount of seed for each tray.

Where to go next

Curious about the plants themselves? What are microgreens explains the stage, and microgreens vs sprouts shows how the two crops differ. If you are planning your space, growing microgreens at home covers supplies and a weekly rhythm. A first tray is quick, cheap to start and forgiving, so pick a variety, set a sow date in the harvest planner and begin.