How to Grow Microgreens and Sprouts at Home: A Step-by-Step Guide

Microgreens and sprouts are often grouped together as quick, indoor ways to grow fresh vegetables, but extension horticulturists and food-safety agencies treat them as two distinct crops with different equipment, timelines and risks. Microgreens are seedlings grown in a growing medium and harvested above the soil line with scissors once true leaves appear, according to Penn State Extension and South Dakota State University (SDSU) Extension. Sprouts are seeds germinated in water, with the whole seedling — including the root — eaten raw, a process the FDA and Clemson University's Home and Garden Information Center (HGIC) say creates conditions that can let bacteria multiply rapidly.

Growing microgreens step by step

1. Choose a shallow container with drainage, such as a standard 1020 greenhouse tray, a repurposed takeout container, or a flowerpot, SDSU Extension says.
2. Fill the tray with a moistened soilless potting mix, seed-starting mix or coconut coir; Penn State Extension notes a thin layer of vermiculite on top is optional.
3. Scatter seeds thinly and evenly across the surface — SDSU Extension advises spacing larger seeds such as peas about 1/2 to 1 inch apart, while Penn State Extension suggests roughly 10 to 15 grams of seed per standard tray — then press seeds lightly into the medium without covering them.
4. Saturate the medium with water and, for faster germination, cover the tray loosely (for example with a plastic bag or a second tray) to hold humidity near 100% until seeds sprout, removing the cover gradually over the following days, per SDSU Extension.
5. Move the uncovered tray to a sunny windowsill or under fluorescent or LED lights once germination begins. Penn State Extension classifies microgreens as a low-light crop that does not need intense supplemental lighting.
6. Water from the bottom by setting the tray in shallow water until the medium is moist, or water gently at the base to keep leaves dry and reduce disease risk, as recommended by Penn State Extension.
7. Harvest with scissors just above the growing medium once three or four true leaves have developed, per SDSU Extension, which says most microgreens are ready within about three weeks; Penn State Extension puts overall production time at about 7 to 21 days, once plants reach roughly 1.5 to 3 inches tall.
8. Store harvested microgreens in a sealed container in the refrigerator. Penn State Extension puts cold-stored shelf life at 10 to 14 days, versus 2 to 4 days at room temperature.

Growing sprouts safely at home

Sprouts carry a distinct food-safety warning. The FDA attributes most sprout-related outbreaks to contaminated seed rather than problems that arise later in growing or handling, and it counts 50 outbreaks and more than 2,600 illnesses linked to contaminated sprouts in the United States between January 1996 and August 2018. Clemson's HGIC adds that the warm, moist conditions needed to germinate sprouts can let bacteria multiply to roughly one billion organisms within two to three days if contamination is present.

1. Buy seed specifically sold for sprouting from a commercial source, as Clemson HGIC recommends, rather than seed intended for planting in soil.
2. Clean and sanitize jars, lids and any sprouting equipment before use, and keep the growing area away from food-preparation surfaces and pets, per Clemson HGIC.
3. Rinse seeds and sprouts in clean, potable water on a regular schedule throughout germination, draining thoroughly each time so the seeds do not sit in standing water.
4. Wash your hands before handling sprouts and rinse the finished sprouts under cool running water directly before eating, as Clemson HGIC advises.
5. Refrigerate harvested sprouts at 40°F (4°C) or below in a sanitized container, and discard any that look limp, slimy or moldy or have an off odor.

Who should avoid raw sprouts

Because pathogens such as Salmonella and E. coli can grow during sprouting even when seeds and equipment are handled carefully, Clemson HGIC advises that children, older adults, pregnant people and anyone with a weakened immune system avoid eating raw or lightly cooked sprouts, including those grown at home. No equivalent home-safety warning applies to microgreens, which are grown in a medium rather than standing water and are typically eaten after being cut above the soil line.

What the nutrition research shows

A USDA Agricultural Research Service (ARS) study, summarized by the agency in a January 2014 report, was led by plant physiologist Gene Lester at the agency's Beltsville, Maryland laboratory and compared 25 commercially grown microgreen varieties with their mature-plant counterparts. The ARS summary of the findings reports that microgreens contained roughly five times greater average levels of vitamins and carotenoids than mature plants of the same species, with vitamin C ranging from 20 to 147 milligrams per 100 grams of fresh weight and carotenoids ranging from 0.6 to 12.1 milligrams per 100 grams. Among the 25 microgreens examined, the ARS reported that red cabbage had the highest vitamin C content, cilantro the highest carotenoid levels, garnet amaranth the highest vitamin K levels, and green daikon radish the highest vitamin E levels. The ARS noted that growing, harvesting and handling conditions affect how much of this nutrient advantage is retained, and said further research on agricultural practices was underway.

Both crops need minimal equipment, work on a windowsill or under basic grow lights, and can be started with a small financial outlay, which university extension offices cite as a reason for their popularity among home gardeners with limited outdoor space.