How to Grow Microgreens Indoors at Home
Written by
Benjamin Miller
Reviewed by
Prof. Samuel Fitzgerald, Ph.D.Discover the process of starting microgreens indoors with a few seed varieties, some containers, and LED light!
Start anyhow, seeds go in a relatively shallow planting tray (with drainage holes if possible) which makes the most sense for indoor growth.
Keep the varieties under a light source that rotates daily while keeping moisture levels checked/consistent.
Mold or issues with leggy growth can generally be solved with better airflow and light.
Cut microgreens at whatever height you prefer using clean scissors techniques anywhere from 2" to 4".
Indoor microgreens are something all year round, and it is entirely possible and more cost-effective than purchasing from the store!
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Knowing how to grow microgreens indoors allows you to develop small nutritional powerhouses right in your home kitchen. Young vegetable greens have up to 40 times the vitamins of full-grown plants. You harvest the microgreens just days after the seeds have germinated and the first leaves appear. This method can be practiced year-round and is not affected by outdoor climate.
With zero experience in gardening, you can start growing these superfoods right inside your home! I always recommend microgreens as the best starting point for urban gardeners. Even on the smallest of balconies or countertops, you have a farm. From the start, you could spend less than twenty dollars on seeds and other supplies.
In a week, you'll have your first sprouts pushing toward brightness. You'll never lose the joy of harvesting your own food. I began my journey years ago with a single tray of radish microgreens. Today, I grow fresh greens for the kitchen every day without any expensive equipment.
Essential Supplies Simplified
The seeds you select dictate your speed of indoor harvests. For example, radish seeds germinate in one to two days, making them a great choice for impatient novice gardeners. Arugula seeds are slower germinators, taking five to seven days to show growth. I try to keep both types of seeds for a staggered harvest in my kitchen garden.
Instead of spending on expensive trays, save by using recycled food containers. Yogurt cups and take-out containers work beautifully, especially if you make drainage holes in them. That gets your start-up costs under $10! My first microgreens grew in washed plastic deli salad boxes.
Look into soil-less alternatives if you have limited counter space. Coconut coir mats and hemp grow pads are designed to fit in small urban kitchens. They eliminate the mess of soil spills and make it easy for you to clean up. I prefer these for apartments, where bags of soil just aren't feasible.
LED lights help supplement inadequate natural light in basements or rooms with a north-facing orientation. Cheap clip-on grow bulbs provide enough lighting without the expensive electricity costs. Hang them 2-4 inches from your seedlings. This method saved my winter harvests when the days were shorter.
Seeds
- Fast-sprouting radish seeds germinate in 1-2 days while broccoli takes 2-3 days; avoid nightshade varieties like tomatoes due to toxicity
- Organic non-GMO seeds ensure safety; store unused seeds in airtight containers in cool dark places for longevity
Growing Medium
- Sterile seed-starting mix prevents disease; coconut coir offers sustainable drainage without compaction issues
- Hydroponic mats work for soilless setups but require precise moisture monitoring every 12 hours
Tools
- Spray bottles provide gentle misting for delicate seedlings; sharp scissors ensure clean cuts during harvesting
- Heating mats maintain optimal 68-75°F (20-24°C) germination temperature in colder environments
Light Source
- South-facing windows offer 4-6 hours of natural light; rotate containers daily for even plant development
- LED panels provide 12-16 hours of supplemental light when placed 2-4 inches (5-10 cm) above plants
Watering Tools
- Narrow-spout watering cans target soil without disturbing seeds; misting bottles prevent compaction during germination
- Self-watering trays reduce maintenance by supplying consistent moisture through capillary action over 24-48 hours
Step-by-Step Planting Process
You want to prepare your soil until it feels like a wrung-out sponge before planting. This is the ideal moisture level, which prevents seeds from drowning while keeps them hydrated. I test mine by taking a handful and squeezing it, with the goal that just one drop of water escapes. Too wet a soil will cause mold, and too dry a soil will impede your germination.
Disperse seeds with a shaking salt device for approximate even spacing and no overlaps. Leave hairline spaces between each seed to avoid crowding. I do this first over a plate in advance to practice the motion. Adequate spacing will help each seedling receive light and air circulation in the future.
For a vital 48-hour darkness period following planting, cover your trays completely. Doing so is comparable to being under soil, stimulating intense sprouting. I use inverted baking sheets as covers for my containers. The biggest danger during this time is any peeking, so do not lift the lid or cover, as this exposes the seedlings to light. It will ruin the germination process!
Once sprouted, remove the covers immediately and expose to light. Timeliness prevents leggy growth and promotes stem strength. I set phone reminders to check trays twice daily. Lamp placement is 2-4 inches above the seedlings for strong growth.
Container Preparation
- Fill containers with 1-2 inches (2.5-5 cm) of pre-moistened organic potting soil, ensuring loose texture for root development
- Create drainage holes if absent using a heated nail or drill bit to prevent waterlogging
Seed Distribution
- Evenly scatter ¼ cup of seeds per 4x4 inch (10x10 cm) area using a salt-shaker motion for uniform coverage
- Avoid seed overlap which causes mold; leave hairline gaps between individual seeds
Covering Technique
- Dust seeds with ⅛ inch (0.3 cm) fine soil layer using a sieve, mimicking natural seed burial conditions
- Gently compress surface with a clean board to ensure soil-seed contact without compacting
Initial Watering
- Mist surface until glistening using spray bottle, maintaining humidity without displacing seeds
- Cover container with opaque lid or tray to create complete darkness for germination
Post-Germination Care
- Remove cover after 48 hours when sprouts emerge, immediately exposing to light source
- Relocate to south-facing window or position LED lights 2-4 inches (5-10 cm) above seedlings
Soil Moisture Control
- Maintain sponge-damp consistency using bottom-watering: pour water into tray base for capillary absorption
- Check moisture twice daily by touching soil surface; add water when surface feels dry
- Prevent overwatering which causes fungal issues by allowing slight drying between sessions
Light Management
- Provide 12-16 hours daily under LEDs or 4-6 hours direct sunlight for proper photosynthesis
- Rotate containers 180 degrees each morning to prevent directional leaning and uneven growth
- Adjust light height weekly to maintain 2-4 inch (5-10 cm) gap as plants develop
Temperature Regulation
- Maintain 65-75°F (18-24°C) using heating mats during germination in cold environments
- Avoid temperatures above 80°F (27°C) which causes bitter flavors in brassica varieties
- Use thermometer probes to monitor root-zone temperature for optimal metabolic activity
Air Circulation
- Position oscillating fan 3 feet (90 cm) away to create gentle air movement
- Open windows daily for 30 minutes to replenish carbon dioxide levels
- Prevent stagnant air pockets which encourage mold spore development on leaves
Sanitation Practices
- Disinfect containers between plantings using vinegar-water solution (1:3 ratio) to kill pathogens
- Sterilize scissors with rubbing alcohol before each harvest to prevent bacterial transfer
- Use fresh potting mix for each batch to avoid soil-borne disease carryover
Daily Care Essentials
In the morning, your priority is managing exposure to light and moisture. Dip trays 180 degrees to ensure all seedlings get adequate sun exposure. Use your fingertip test for soil moisture by gently pressing around the surface, looking for a sponge-like dampness. In the evening, it means reducing light exposure and preparing for a dark cycle.
You'll want to master the fingertip test vs visual inspection so you can be confident your moisture checks are accurate. The fingernail vision is an approximate test of whether it is truly damp. For example, use your fingernail to gently prod the soil for about half an inch to assess the actual moisture level. Visual checks can lead you astray, as the surface may appear dry, but wet soil lies beneath. I typically combine both processes for double-checking babysitting and more reliable hydration controls.
Adjust the lights every other day as the seedlings grow taller. Initially, lights should be positioned 4 inches above the sprouts, then lowered to 2 inches when true leaves emerge. This way, seedlings will not get leggy while building strong stems. I mark my calendar for these light height adjustments.
Avoid fungal challenges using daily ventilation measures. If running a fan isn't feasible, an oscillating fan can be used during the day for about 30 minutes. If you can crack and open the windows during this time, it will allow for the exchange of fresh air. The air passage is similar to the natural environment and helps keep mold away from your indoor garden.
Light Management
- Rotate containers 180 degrees each morning to ensure even sun exposure on all seedlings
- Adjust artificial lights to maintain 2-4 inch (5-10 cm) distance from plant tops as they grow
Watering Schedule
- Mist seedlings twice daily using spray bottle until true leaves develop
- Transition to bottom-watering method once roots establish, filling tray base with ¼ inch (0.6 cm) water
Environmental Control
- Maintain 65-75°F (18-24°C) temperature range using heating mats in cooler areas
- Provide 4-6 hours darkness nightly; cover trays if ambient light exceeds this duration
Growth Monitoring
- Measure height daily using ruler; ideal growth rate is ¼-½ inch (0.6-1.3 cm) per day
- Inspect for discoloration or legginess indicating light/water adjustments needed
Sanitation Practices
- Wipe tray rims daily with vinegar solution to deter mold formation
- Sterilize tools before use with 70% isopropyl alcohol solution
Harvesting and Storage Guide
Find the peak harvest timing by observing identifiable visual indicators specific to the variety. For instance, pea shoots are suitable for harvest at 3-4 inches, with curling tendrils. Broccoli microgreens begin to develop true leaves around day 10. Radish microgreens have fully opened cotyledons when harvested at 3 to 4 inches tall. For sunflower greens, I like to harvest them when they are between 4 and 6 inches tall, before they develop true leaves.
When cutting to promote future regrowth, use scissor cutting techniques. When cutting peas, trim ½ inch above the soil at a 45-degree angle to promote possible second harvests. When cutting a single harvest crop, such as arugula, trim just above the soil line. Always ensure that you sterilize your cutting blades with rubbing alcohol after each tray.
Maximize shelf life by selecting the right storage technique. Wrapping pea shoots in paper towels preserves them for 7-10 days. Storing tender radish greens in an airtight container keeps them crisp for close to two weeks. For long-term storage, blanch and freeze microgreens to preserve their nutrients for months.
Ensure the implementation of Food Safety Protocols for all post-harvest handling. If you are cutting greens, rinse them immediately in cold, running water, and then pat them dry with clean paper towels before storage. Use separate cutting boards for microgreens and raw meats to avoid any cross-contamination.
Pea Shoots
- Harvest at 3-4 inches (7.5-10 cm) height using scissors; cut ½ inch (1.3 cm) above soil for regrowth
- Yields 2-3 harvests per planting; wait 5-7 days between cuttings
Broccoli Microgreens
- Cut at true leaf stage (10-14 days) just above soil line; single harvest only
- Ideal height: 2-3 inches (5-7.5 cm); delay causes woody stems and bitter flavor
Radish Sprouts
- Harvest when cotyledons fully open (5-7 days); 1-2 inch (2.5-5 cm) height optimal
- Use sharp scissors; avoid pulling to prevent soil contamination
Sunflower Greens
- Harvest before true leaves develop (8-10 days) at 4-6 inches (10-15 cm)
- Remove seed hulls before cutting; single harvest due to energy depletion
Arugula Microgreens
- Cut at 2 inches (5 cm) when first true leaves appear (12-14 days)
- Peppery flavor peaks at this stage; regrowth not recommended
Troubleshooting Common Problems
To address mild yellowing leaves, begin by examining your watering practices. Oftentimes, this problem is attributed to overwatering, especially in enclosed, poorly ventilated areas of the home. Improve drainage immediately and switch to bottom watering. Prevent future occurrences by allowing the soil surface to dry out slightly between waterings.
Moderately leggy seedlings will be seen as lighting failures. Leggy pale seedlings are the result of inadequate light intensity or light duration. Move lights closer, immediately to 2 inches above seedlings. Use daily tray rotation and light cycles of 12-16 hours to prevent future occurrences.
Control serious mold infection by promptly isolating plants and adjusting airflow. White fuzz indicates excess humidity and stagnant air. Remove any infected plants and increase airflow immediately. Immediately apply cinnamon spray as a natural fungicide. Avoid mold by facilitating air circulation.
Identify newbie errors through recognizable visual cues in the early stages, like sluggish germination or wilting. These most likely stem from storing the seed incorrectly and managing temperature instability. Adjust with common prior methods, such as heat mats or dry soil.
Fungal Outbreaks
- Apply cinnamon-water spray (1 tsp/8 oz/236 ml) as natural fungicide
- Isolate affected trays immediately to prevent spread to healthy plants
Pest Infestations
- Use neem oil solution (2 tbsp/1 gal/3.8 L water) for aphids/fungus gnats
- Introduce beneficial nematodes for soil-dwelling larvae control
Nutrient Lockout
- Flush soil with pH balanced water (6.0-6.5) to restore nutrient uptake
- Test runoff water with pH strips; adjust with vinegar/baking soda
Temperature Stress
- Relocate trays from cold drafts or direct heat sources immediately
- Use insulation boards under trays in cold environments
Light Burn
- Raise lights 2-4 inches (5-10 cm) immediately if leaf curling occurs
- Provide 4-hour shade period during peak light intensity hours
5 Common Myths
Microgreens need direct sunlight for indoor development
Microgreens flourish under indirect natural light or backed by artificial LED light, typically needing 4-6 hours of exposure every day. South-facing window light will be adequate in many homes, while inexpensive grow lights provide similar results all year long - and without providing direct sunlight that can actually burn delicate seeds.
Similar to other plants, many microgreens can regrow and produce after harvest
Unlike perennial types of herbs or vegetables, most microgreen varieties expend their seed energy during their growth. The only consistent and dependably cut microgreen that will regrow and produce a secondary harvest is pea shoots, providing you cut the shoot an inch above the soil. Other types, like radish and broccoli microgreens, do not regrow as reliably or effectively and should be replanted to benefit from microgreen growth in succession.
Microgreens can be grown with costly kits and specialized equipment
You only need inexpensive basics to grow microgreens: a recycled food container for a tray, general potting soil, and seeds that cost under $5 for a batch. Although LED lights can enhance growth, it is not required when you are growing microgreens in a sunny area. The total cost for a basic set up is, at most, less than $20, versus $50 or more for commercial growing kits.
Microgreens can become contaminated by E coli, just like sprouts.
When grown in soil or mats, microgreens have a lower chance of becoming contaminated than sprouts, which are grown in high moisture environments. Rinsing microgreens before eating can remove surface bacteria, making microgreens much safer to eat than sprouts which are constantly bathed in water that allows bacterial growth.
It takes many months before you can harvest microgreens
Most varieties can be harvested at around 7-14 days, whereas the fastest, radish, will be ready in about 5-7 days. This process can happen all year, and you can start new batches weekly. The slowest varieties, like arugula, take only around 14 days, which is still significantly faster than traditional vegetables that can take 60-90 days, like tomatoes or peppers.
Conclusion
Even for absolute beginners, growing microgreens indoors is exceptionally easy and you will start harvesting within days, not months. This fast pace provides immediate gratification that is lacking in traditional gardening. Almost all of my students have success with their first tray.
Experience harvests all year round, even in inclement outdoor weather or with inadequate space. Whether you are dealing with a snowstorm or you live in an apartment, having an indoor garden is not hindered. I consistently produce by rotating trays every week. Your kitchen counter is transformed into an indoor farm for every season.
Save substantially compared to buying expensive store-bought organic greens. Homegrown microgreens cost pennies per serving. My calculations show 75% savings over supermarket prices. This efficiency makes premium nutrition accessible.
Experiment with different types of seeds to explore flavors. Consider mixing a spicy radish with a mild pea shoot in salads. You can also play with colors and textures to make it visually interesting. Follow your taste buds to find the combinations you enjoy most.
External Sources
Frequently Asked Questions
Can microgreens be grown indoors year-round?
Yes, microgreens thrive indoors year-round with consistent conditions. Maintain 65-75°F temperature using heating mats in winter, and provide sufficient LED lighting for 12-16 hours daily regardless of outdoor seasons. Proper ventilation prevents humidity issues during summer months.
Do microgreens need direct sunlight to grow?
Microgreens don't require direct sunlight and actually grow better with controlled lighting. Use south-facing windows for natural light or affordable LED panels placed 2-4 inches above plants. Direct sun often causes scorching while insufficient light leads to leggy growth.
Is it cost-effective to grow microgreens at home?
Growing microgreens at home saves significant money compared to store-bought options. Initial setup costs under $20 for seeds, recycled containers, and soil. Each batch yields $10-15 worth of greens while costing less than $2 to produce.
How do I prevent mold in microgreens?
Prevent mold through three key practices: First, use bottom-watering instead of top spraying. Second, ensure proper air circulation with fans. Third, maintain ideal moisture levels where soil feels like a wrung-out sponge without being soggy.
- Bottom-watering technique
- Daily fan circulation
- Moisture monitoring
Can you reuse microgreen soil?
Reusing soil is not recommended due to disease risks. Microgreens deplete nutrients rapidly and may leave behind pathogens. Always use fresh, sterile potting mix for each planting cycle to ensure healthy growth and prevent contamination issues.
What are common mistakes beginners make?
Beginner errors include overwatering leading to mold, insufficient light causing leggy growth, planting seeds too densely, and harvesting too early or late. Proper spacing, moisture control, and daily light monitoring prevent these issues effectively.
Are homegrown microgreens safer than store-bought?
Homegrown microgreens have lower contamination risks when properly handled. Unlike commercial sprouts grown in water, soil-based home cultivation reduces bacterial exposure. Thorough rinsing before consumption further minimizes risks, providing safer nutrition than store alternatives.
How soon can you harvest microgreens?
Harvest times vary by variety but generally range from 5-14 days. Fast-growing radish microgreens are ready in 5-7 days, while arugula takes 12-14 days. Harvest when true leaves appear at 2-4 inches height for peak flavor.
Do microgreens attract indoor pests?
Microgreens rarely attract pests when grown properly indoors. Prevent issues by sterilizing containers between plantings, avoiding overwatering, and ensuring good airflow. Neem oil solutions control occasional fungus gnats without harmful chemicals.
What supplies are essential for starting?
Essential startup supplies include five key items: shallow containers with drainage, quality potting soil, fresh seeds, spray bottles for gentle watering, and either natural light sources or affordable LED grow lights for consistent illumination.
- Draining containers
- Sterile soil
- Microgreen seeds
- Spray bottle
- Light source
