How to Grow Microgreens at Home
Microgreens are one of the most accessible crops you can grow indoors. They don't require a garden, a greenhouse, or any prior farming experience. With a handful of supplies and a sunny windowsill — or a simple grow light — you can go from seed to harvest in as little as seven days. This guide walks you through everything you need to know to get started, from choosing the right supplies to cutting your first tray.
What Supplies Do You Need?
Before you plant your first seed, gather your equipment. The good news is that none of it is expensive or hard to find.
Growing Trays
You'll need two shallow trays that fit inside each other — one with drainage holes (the planting tray) and one without (the bottom tray that catches water). Standard 10x20 inch nursery flats work perfectly and cost just a couple of dollars each at any garden center. You'll also want a solid lid or a second solid tray to use as a weight during the germination phase.
Growing Medium
Microgreens don't need deep soil — they only need about an inch of growing medium. Options include:
- Potting mix: A fine, lightweight potting soil works well and is widely available. Avoid mixes with large bark chunks.
- Coco coir: A popular choice among dedicated growers. It's clean, rehydrates easily, and holds moisture well.
- Hydroponic mats: Jute or hemp mats are mess-free and work great for many varieties.
Fill your planting tray to about an inch deep and press it down lightly so there are no air pockets.
Seeds
Use seeds that are specifically sold for microgreen or sprouting use — these are untreated and safe for fresh consumption. Treated field seeds (intended for outdoor planting) can carry chemical coatings that you don't want on food you'll eat raw. Great beginner varieties include broccoli, radish, sunflower, pea shoots, and salad mix blends. Each has slightly different germination times and flavor profiles, which we'll cover below.
Light
After the blackout germination phase, microgreens need light to green up and grow. A south-facing window with good natural light can work, but the intensity and consistency of a dedicated grow light produces better results. T5 fluorescent or LED grow lights hung 2–4 inches above the trays for 12–16 hours per day are the standard setup for home growers. If your windowsill greens look leggy or pale, more light is the fix.
Step-by-Step: From Seed to Harvest
Step 1: Soak Your Seeds (Optional But Helpful)
Large seeds like sunflower and pea shoots benefit from soaking in cool water for 8–12 hours before planting. This softens the seed coat and kickstarts germination. Small seeds like broccoli, radish, and arugula don't need pre-soaking — they germinate quickly on their own. Drain and rinse soaked seeds before use.
Step 2: Prepare Your Tray
Moisten your growing medium before filling the tray — it should feel like a wrung-out sponge, damp but not dripping. Fill the planting tray to about one inch deep and level it out with your hand or a flat object. Good even contact between seeds and medium is key to uniform germination.
Step 3: Sow Your Seeds
Spread seeds evenly across the surface of the tray. You want good density — seeds can touch but shouldn't pile up in thick clumps. Use these general seeding rates as a starting point:
- Broccoli: about 1–1.5 oz per 10x20 tray
- Radish: about 1.5–2 oz per tray
- Sunflower: about 4–6 oz per tray (they're large seeds)
- Pea shoots: about 4–6 oz per tray
- Salad mix: about 1 oz per tray
After spreading seeds, mist the top lightly with a spray bottle to help them settle into contact with the growing medium.
Step 4: The Blackout Period
Stack a second tray on top of the seeds and press it down gently. The weight helps seeds make good contact with the growing medium and promotes even, upright germination. Place the stack in a warm spot (65–75°F is ideal) and leave it undisturbed for 2–4 days depending on the variety. Check once a day — if the medium feels dry, add a small amount of water to the bottom tray so roots can wick moisture up. Do not water from the top during blackout.
When you peek and see that the seeds have sprouted with stems about half an inch tall, they're ready for light.
Step 5: Move to Light
Remove the top tray and move your microgreens to your light source. The greens will be pale yellow at first — that's normal. Within a day or two of light exposure they'll turn a healthy green as chlorophyll develops. Continue bottom watering: pour a small amount of water into the solid tray beneath and allow roots to absorb it. Empty any standing water after 30 minutes to avoid mold. Avoid wetting the leaves and stems from above.
Step 6: Harvest
Most microgreens are ready to harvest at the cotyledon stage — when the seed leaves have fully opened and turned green, but before the first true leaves appear. This is typically day 7–14 depending on variety. Use clean, sharp scissors or a knife and cut just above the growing medium. Harvest in the morning when the greens are most crisp. Rinse gently, spin or pat dry, and use immediately or store in the refrigerator.
Tips for Success
Keep It Dry on Top
Moisture sitting on leaves and stems is the fastest path to mold. Always bottom water after the blackout phase. Good airflow in your growing space also helps — a small fan running on low nearby can make a real difference.
Temperature Matters
Most microgreens germinate best between 65 and 75°F. Too cold and germination slows down or stalls. Too warm and you may encourage mold growth. Your kitchen counter in most seasons is a fine environment.
Don't Over-Seed
It's tempting to pack seeds in thinking you'll get more greens, but over-seeding leads to poor airflow, uneven germination, and mold. Stick to the seeding rates above and adjust from there based on your results.
Use Fresh Seeds
Old seeds have lower germination rates and can lead to patchy, uneven trays. Buy from a reputable microgreen seed supplier and store seeds in a cool, dry place.
Common Beginner Mistakes
- Watering from the top: This gets leaves wet and invites mold. Bottom water instead.
- Not enough weight during blackout: Seeds that don't have good contact with the medium can germinate unevenly or produce "helmet heads" — seeds that can't shed their hulls.
- Too little light: Leggy, pale microgreens that fall over are a light problem. Move them closer to the light source or add a grow light.
- Harvesting too late: Once the first true leaves appear, flavor and texture begin to change. Harvest at the cotyledon stage for the best results.
- Skipping cleanup between grows: Wash and dry your trays thoroughly between batches to prevent cross-contamination and mold carryover.
When to Harvest: Cotyledon vs. First True Leaf
Understanding harvest timing is one of the most important skills in microgreen growing. The cotyledon stage refers to the first seed leaves that emerge — these are not true leaves but rather nutrient-storing structures that push out of the seed. At this stage, the plant is packed with concentrated nutrients and flavor. Most growers and culinary professionals prefer microgreens harvested here.
The first true leaves look different from the cotyledons — they resemble miniature versions of the plant's mature leaves. Some growers prefer to wait until this stage for varieties like pea shoots and sunflower, as the additional growth time adds stem length and bulk. But for most microgreens, the cotyledon stage hits the sweet spot of nutrition, flavor, and tenderness.
Skip the Growing and Buy Local Instead
If the idea of managing trays, timing blackout periods, and monitoring moisture levels isn't appealing, there's a simpler option: buy your microgreens already grown, harvested the night before, and ready to eat. Teeny Greeny Microgreens in Broken Arrow, Oklahoma grows small-batch microgreens weekly and makes them available at the Broken Arrow Farmers Market every Saturday. Owner Brooke harvests the night before market so every clamshell you pick up is as fresh as it gets.
You can preorder online to guarantee your varieties and skip the sellout scramble. Whether you're grabbing broccoli, radish, arugula, pea shoots, sunflower, or salad mix, Teeny Greeny keeps your weekly greens covered without any tray maintenance required on your end.
Of course, growing your own is a genuinely rewarding experience — and if you do start your home setup, knowing what goes into the process makes you appreciate the craft even more. But whether you grow or buy, getting more microgreens into your diet is always the right move.