How Long Do Microgreens Take to Grow?

One of the most appealing things about microgreens is how quickly they go from seed to harvest. Unlike a vegetable garden where you might wait months for a crop, microgreens can be on your plate in as little as a week. But grow times vary significantly by variety, and a few environmental factors can speed things up or slow them down. Here's a clear breakdown of what to expect — from the first day of planting to harvest-ready greens.

The General Timeline: Seed to Harvest

Most microgreens are ready to harvest somewhere between 7 and 21 days after seeding, with the majority of popular varieties falling in the 7–14 day window. The timeline breaks into three distinct phases:

Days 1–2: Seed prep and planting. Large seeds like sunflower and pea are soaked 8–12 hours before sowing. All seeds are sown into moistened growing medium and covered.
Days 2–5 (the blackout period): The covered trays are kept in warm, dark conditions. Germination happens here. Roots anchor into the medium and stems push upward.
Days 5–14+ (the light phase): Trays are uncovered and moved to light. The seedlings green up rapidly and grow to harvest height. This phase ends when the cotyledons (seed leaves) are fully open and the greens are at peak flavor.

The exact length of each phase depends heavily on which variety you're growing and the conditions in your growing space.

Grow Time by Variety

Here are the most popular microgreen varieties along with their typical seed-to-harvest timelines under standard conditions (65–75°F, good light, proper moisture).

Broccoli: 7–10 Days

Broccoli is one of the fastest and most reliable microgreens to grow, which is a big part of why it's so popular among both home growers and commercial operations. Seeds germinate within 2–3 days, and the cotyledons are fully open and bright green by day 7 or 8 in ideal conditions. Broccoli microgreens have a mild, clean flavor and are highly versatile in the kitchen. They're also among the most studied for nutritional content, particularly for sulforaphane, a potent antioxidant compound.

Radish: 6–8 Days

Radish is arguably the fastest commonly grown microgreen. It germinates aggressively — you'll often see sprouts pushing up within 24–36 hours of planting — and it hits harvest size in as little as 6 days under warm conditions. The flavor is bold and peppery, which makes it a favorite for adding punch to dishes. The bright red or pink stems (depending on variety) also make it visually striking. Because radish grows so quickly, it's a great first crop for beginners who want fast results.

Arugula: 7–10 Days

Arugula microgreens germinate quickly and develop their characteristic nutty, peppery flavor at the cotyledon stage. One note for arugula: the seeds are mucilaginous, meaning they become gel-like when wet. This is normal — don't be alarmed by the sticky coating. Sow arugula seeds a little more thinly than other varieties and be careful not to overwater. Harvest at days 7–10 when the cotyledons are open and the flavor is at its peak.

Pea Shoots: 10–14 Days

Pea shoots take a bit longer than brassica varieties like broccoli and radish because they're larger plants developing from larger seeds. Soak the seeds for 8–12 hours before planting to give them a head start. The blackout period runs about 3–4 days, and the light phase is another 6–10 days. Pea shoots are worth the wait — they're sweet, tender, and have a flavor that genuinely tastes like fresh spring peas. They also produce more biomass per tray than most microgreens, giving you a satisfying yield.

Sunflower: 10–14 Days

Sunflower microgreens are another large-seed variety that benefits from pre-soaking (8–12 hours). They take 10–14 days from seed to harvest, and during the blackout phase they need more weight on top than smaller varieties to help them shed their seed hulls and grow upright. Once in light, they develop quickly into thick, nutty-flavored greens with substantial stems. Sunflower microgreens have a satisfying crunch and work well as a salad base or in dishes where you want some body to the green. Many growers consider them the most filling and substantial microgreen to eat.

Salad Mix: 7–12 Days (Varies)

Salad mix microgreens are typically a blend of multiple brassica seeds — often broccoli, cabbage, kohlrabi, kale, and similar varieties — selected because they have similar grow times and compatible flavors. The overall harvest window is usually 7–12 days. Because different seeds in the blend may germinate at slightly different rates, checking the tray as a whole and harvesting when the majority look ready is the practical approach. Salad mix gives you variety in a single tray and is ideal for people who want different flavors and textures in every bite.

What Affects Grow Time?

The timelines above assume reasonably controlled conditions. In practice, several factors can shorten or lengthen your grow cycle.

Temperature

Temperature has the single biggest impact on germination and growth speed. Most microgreens germinate best between 65 and 75°F. Below 60°F, germination slows significantly and you may see uneven sprouting. Above 80°F, germination can speed up slightly but mold risk increases, and the growing environment becomes harder to manage. A consistent kitchen temperature is usually adequate for most home growers. If you're growing in a garage or basement in winter, consider a small heat mat under the trays during the germination phase.

Light Intensity and Duration

Once microgreens are out of the blackout phase, light drives growth. Weak light — a dim windowsill or a grow light that's too far away — produces leggy, pale greens that take longer to reach harvest size and have weaker flavor. Stronger light (or a grow light positioned 2–4 inches above the trays, running 12–16 hours per day) produces compact, upright, intensely colored greens that reach harvest readiness on the faster end of their typical range.

Seed Quality and Freshness

Seeds lose viability over time. Fresh seeds from a reliable supplier will germinate faster and more uniformly than seeds that have been sitting in storage for years. Buy seeds specifically labeled for microgreen or sprouting use — these are untreated and have typically been selected for high germination rates. Treated field seeds (coated for outdoor planting) are not appropriate for microgreens.

Moisture Management

During the light phase, underwatering causes stress and slows growth. Overwatering causes mold, which can wipe out a tray. The goal is consistently moist (not wet) growing medium throughout. Bottom watering — adding a small amount of water to the solid tray beneath and letting roots wick it up — is the most effective method. It keeps the surface and stems dry while maintaining moisture at the root level.

Seeding Density

Overcrowded trays restrict airflow and can slow growth in the middle of the tray where seeds compete most. Following recommended seeding rates gives each seedling enough space to reach up into the light rather than being crowded sideways.

The Blackout Period: Why It Matters

The blackout phase — those first 2–5 days when trays are stacked and weighted in the dark — is one of the most important parts of the microgreen grow cycle, and it's often misunderstood by beginners.

During blackout, the seeds germinate and the young seedlings "etiolate" — they reach upward in search of light, which produces longer, straighter stems. The weight of the top tray pressing down on the seeds helps them shed their hulls, creates even contact with the growing medium, and promotes upright growth. Without this period, many varieties produce short, uneven stems and struggle to shed seed coats, a problem called "helmet heads."

The blackout period should end when the seedlings have pushed up against the top tray and stems are roughly half an inch to an inch tall. At that point, they're ready for light and will green up within 12–24 hours of exposure.

Signs That Microgreens Are Ready to Harvest

Don't just rely on the calendar — look at the plants. Microgreens are ready to harvest when:

The cotyledons (seed leaves) are fully open and flat
The color is vibrant and evenly green (or the expected color for that variety)
Stems are upright and firm, not flopped over
The first true leaves have not yet fully appeared (for most varieties, you want to harvest before this point)
The tray smells fresh and clean, not musty

Harvest in the morning when the greens are at their crispest. Cut just above the soil line with clean, sharp scissors.

How Teeny Greeny Runs Its Weekly Harvest Cycle

At Teeny Greeny Microgreens in Broken Arrow, Oklahoma, the growing schedule is built around a consistent weekly rhythm. Trays are seeded on a rolling schedule so that multiple varieties are always at different stages simultaneously — some germinating, some in the light phase, some ready to cut. Harvest happens the night before the Broken Arrow Farmers Market so that greens go from tray to clamshell to customer hand within hours.

That timing is intentional. Fresh-cut microgreens stored dry and cool will last 7–10 days in a refrigerator, but the earlier in that window you start, the more shelf life you have at home. Buying from a grower who harvests to order — rather than one who cuts days in advance and warehouses inventory — makes a real difference in what you take home.

If you want to pick up fresh microgreens without managing any of the grow cycle yourself, you can preorder from Teeny Greeny ahead of Saturday market. It takes two minutes and guarantees your varieties are ready when you arrive.