7x14 Microgreen Tray Kit: Complete Growing Guide for Beginners

Want to start growing fresh microgreens at home without the mess of soil? The 7x14 On The Grow Microgreen Tray Kit has become our most popular grow tray system for home growers—and for good reason. This compact, all-in-one kit makes growing nutrient-dense microgreens simple and reliable, whether you're brand new to growing or looking for a better system.

In this comprehensive guide, we'll walk you through everything you need to know about using the 7x14 tray kit, from unboxing to harvest. By the end, you'll understand why thousands of home growers have made this their go-to microgreens setup.

Watch our complete video tutorial below, then follow along with the detailed written instructions:

 

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What Is the 7x14 Tray Kit?

The 7x14 On The Grow Microgreen Tray Kit is a complete microgreens growing system designed specifically for home growers who want fresh, organic greens without dedicating their entire kitchen to the project.

What's Included in the Kit:

• (1) White Mesh Tray - Perforated bottom allows roots to grow through for bottom-watering
• (1) White Reservoir (Base) Tray - Holds water for easy bottom-watering system
• (1) Clear Humidity Dome - Dual-purpose: flips upside down as weighted cover during germination, then right-side up for humidity control
• (2) Silicone Reusable Grow Mediums - Pre-cut 7" × 14" silicone sheets with 1.2mm holes for soil-free growing
• (1) Scraper/Cleaning Tool - Makes cleanup quick and easy

What's NOT Included:

• Seeds (so you can choose your favorite varieties)
• Grow lights (optional - windowsill growing works too)
• Nutrients/fertilizer
• Soil or coco coir (if you prefer traditional growing)

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Why This Kit Works: 5 Key Benefits

1. Beginner-Friendly Design

"The setup is very easy, and watching OTG videos helped take the guesswork out of how much seed and water to use." — Customer Review

The 7x14 kit eliminates the confusion that stops most people from starting. Everything works together seamlessly - the mesh tray nests perfectly in the reservoir, the dome fits precisely for both weighted germination and humidity control, and the silicone sheets are pre-cut to size. No modifications, no guesswork, no frustration.

2. Perfect Size for Home Growing

One of the biggest complaints we hear about microgreens is that standard 10x20 trays produce too much at once for small families. The 7x14 kit solves this perfectly.

Production capacity: One tray feeds a family of 2-3 for about 3-4 days

Real customer experience: "One tray of microgreens lasts my family of 3 about 4 days so having 2 for a particular plant makes sure our family never runs out of something we enjoy such as broccoli."

The compact footprint (14.4" L × 7.25" W × 4.2" H with dome) fits on countertops, windowsills, under cabinets, or on small shelving units where larger trays simply won't work.

3. Low-Maintenance Watering

This is the feature customers rave about most.

"The real reason I stick with these trays is the ease of water maintenance. My work schedule fluctuates drastically from day to day so being able to simply check the water every 2-3 days is great." — Customer Review

Unlike top-watering methods that require daily attention, the reservoir system holds enough water for 2-3 days. The clear sides let you see water levels at a glance. For busy schedules, forgetful growers, or anyone who wants fresh greens without babysitting them, this is a game-changer.

4. Grow Soil-Free or Traditional

The kit includes two silicone reusable grow mediums, which means you can grow completely soil-free if you want—no mess, no disposal, just rinse and reuse. But if you prefer the traditional route, the trays work perfectly with soil or coco coir too.

Soil-free benefits:

• No mess on countertops
• 5-minute cleanup time
• Reusable for hundreds of grows
• Perfect for apartments or small spaces
• Easier root harvesting

Traditional medium option:

• Use seed-starting soil or coco coir
• Holds ~6 cups of medium
• More familiar for experienced gardeners
• Works great for certain varieties

5. Built to Last

"This tray also feels good in the hands. The plastic construction is thick. I'm not afraid of it breaking if I drop it or am a bit rough with it in the sink. You can tell it was built to last for years of use." — Customer Review

Made from food-safe PP (Polypropylene) plastic, these trays are dishwasher safe (top rack, no heat), thick enough to handle daily use, and backed by a 1-year warranty. Customers consistently mention how solid and well-built the kit feels compared to cheaper alternatives.

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How to Grow Microgreens with the 7x14 Kit

We'll cover two methods: growing with the included silicone reusable grow medium (soil-free), and growing with soil or coco coir.

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Method 1: Growing with Silicone Reusable Grow Medium (Soil-Free)

This is the method most home growers prefer because it's clean, simple, and the silicone lasts for hundreds of uses.

Step 1: Set Up Your Tray

1. Place the white mesh tray on top of the white reservoir (base) tray
2. Optional: Add 1-3 cups of water to the reservoir for extra humidity during germination
3. Set the clear humidity dome aside for now

Step 2: Add the Silicone Grow Medium

1. Take one silicone sheet and place it evenly on top of the mesh tray
2. Note: The silicone will cover the mesh holes but won't fit perfectly corner to corner - this is normal and doesn't affect growing
3. Lightly mist the silicone with water to prep for seeding (this helps seeds stick)
4. Avoid pooling water - just a light mist

Step 3: Seed Your Tray

Recommended varieties for beginners:

• Broccoli
• Radish
• Kale
• Collard
• Peas
• Mustard

Seeding rates:

• Small seeds (broccoli, radish, kale): 1-2 tablespoons (15-30 grams)
• Large seeds (peas, sunflower, beans): 3-6 tablespoons (45-90 grams)

How to seed evenly:

1. Lightly mist the silicone to prevent seeds from bouncing
2. Sprinkle seeds evenly across the entire surface
3. Avoid clumps and bare spots
4. Don't worry about perfection - close enough works great

For detailed seeding charts by variety, download our free seeding guide.

Step 4: Water Your Seeds

1. Use a spray bottle to generously water the seeds
2. Spray for about 13 seconds with a hand pump sprayer
3. Seeds should be wet but not swimming
4. If you see large pools forming, wick up excess with a cloth or paper towel
5. Small droplets on the silicone are fine

Critical watering tip: Overwatering is the #1 cause of mold and germination failure. You want everything wet, but not waterlogged.

Step 5: Cover and Apply Weight

1. Flip the clear humidity dome upside down
2. Place it directly on top of the seeds
3. The dome's weight will make contact with the seeds (this is exactly what you want)
4. Optional: Add extra weight if needed (a book or another tray)

Why this works: The upside-down dome serves two purposes - it weighs down the seeds to improve germination and traps humidity. This is one of the cleverest features of the kit.

Step 6: Germination Phase (2-4 Days)

1. Place the tray in a dark location (closet, cabinet, or dark shelf)
2. Mist seeds twice daily - morning and evening
3. Check progress daily
4. What you're looking for: Seeds pushing the dome up, more yellow plants showing than dark seed hulls

Germination timeline by variety:

• Broccoli, radish, mustard: 2-3 days
• Kale, collard: 3-4 days
• Peas: 3-5 days
• Sunflower: 4-6 days

Step 7: Transition to Humidity Dome

When your crop is about 75% germinated (more yellow/green than dark seeds):

1. Lightly mist the plants
2. Check that roots are developing
3. Flip the dome right-side up to create a proper humidity dome
4. Place it on top of the mesh tray
5. Return to the dark shelf for 1-3 more days

Purpose: The humidity dome creates warmth and moisture that encourages rapid upward growth, making your microgreens taller and easier to harvest.

Important: Don't leave them in the humidity dome too long (max 1-3 days) or you'll get lanky, weak stems that topple over. You want just enough stretch for easier harvesting.

Step 8: Expose to Light and Begin Bottom-Watering

1. Remove the humidity dome completely
2. Place the tray under grow lights or on a bright windowsill
3. Add up to 3 cups of pH-balanced nutrient water (5.5-6.5 pH) to the reservoir tray
4. The water should just reach the inner shelf supports - not flooding the mesh

Watering schedule:

• Check water levels daily
• If crops drink quickly, replenish daily
• For slower drinkers, refresh every 2-3 days
• Water should always be touching the bottom of the roots

How to check water level: Slightly lift the mesh tray and look for water droplets on the bottom or roots. If you don't see any, add more water. You'll feel slight resistance (like a weak magnet) when water is touching the tray.

Fertilizer guidance:

• With silicone: Use hydroponic nutrients mixed at half-strength
• Good options: OceanSolution 2-0-3 (0.5oz per gallon)
• Always pH-balance water to 5.5-6.5 range after adding nutrients

Step 9: Harvest (7-14 Days)

Your microgreens are ready when:

• First true leaves are forming (the second set of leaves)
• Plants are 2-3 inches tall
• Vibrant green color
• Strong stems

How to harvest:

1. Use clean scissors or a sharp knife
2. Cut just above the silicone surface
3. Rinse harvested greens and enjoy!

Yield expectations: One 7x14 tray produces approximately 2-4 ounces of fresh microgreens depending on variety.

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Method 2: Growing with Soil or Coco Coir

Prefer traditional growing? The 7x14 kit works great with soil or coco coir too.

Step 1: Set Up and Fill Your Tray

1. Place the mesh tray on top of the reservoir tray
2. Fill the mesh tray with 6 cups of seed-starting soil or pre-moistened coco coir
3. Break apart any clumps
4. Spread medium evenly
5. Gently press flat without compacting

Step 2: Seed Your Tray

Follow the same seeding rates and process as the silicone method (see Step 3 above).

1. Lightly mist the soil/coco to prevent seeds from bouncing
2. Evenly distribute seeds across the surface
3. Avoid clumps and bare spots

Step 3: Water Your Seeds

1. Spray seeds with regular or filtered water for about 13 seconds
2. Seeds should be wet, medium should be moist but not saturated
3. No pooling or over-saturation

Step 4: Cover and Weight

Same as silicone method - flip the dome upside down and place on seeds.

Step 5: Germination (2-4 Days)

1. Place in dark location
2. Mist twice daily (morning and evening)
3. Monitor germination progress

Step 6: Humidity Dome Transition

When 75% germinated, flip dome right-side up and return to darkness for 1-3 days.

Step 7: Light and Bottom-Watering

1. Remove dome
2. Place under lights or on windowsill
3. Add up to 3 cups of water to reservoir tray
4. For coco coir: Use pH-balanced water (5.5-6.5) with nutrients
5. For soil: Use plain water only - soil has nutrients already

Important difference: Don't add hydroponic nutrients if using soil. This can cause tip burn and stunted growth. Soil provides all the nutrition microgreens need.

Step 8: Harvest (7-14 Days)

Same timeline and process as silicone method. Cut, rinse, enjoy!

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Cleaning and Maintenance

One of the biggest advantages of the 7x14 kit is how easy it is to clean and maintain.

Cleaning the Trays and Humidity Dome

Method 1 (Recommended):

1. Hand-wash with hot water and food-safe dish soap
2. Rinse thoroughly
3. Air dry or towel dry
4. Store out of direct sunlight

Method 2 (Dishwasher):

1. Top rack only
2. No heat/no heated dry cycle
3. Heat can warp the trays

Cleanup time: About 2-3 minutes per tray

Cleaning the Silicone Grow Medium

"The scraper is great and just the right size for everything. It's a simple piece of plastic but oh boy does it clean up the mesh tray and silicone mat well." — Customer Review

Step-by-step cleaning:

1. Remove roots: Use the included scraper tool to gently remove root mass from the silicone
2. Wash: Use warm water and free-and-clear soap (Dr. Bronner's or Seventh Generation work great)
3. Gentle scrubbing: Use your hands to lather and rinse - avoid brushes or abrasive scrubbers that can damage the silicone
4. Rinse thoroughly: Make sure all soap residue is gone

Sanitization (choose one method):

• Option 1: Boil in water for 1-2 minutes
• Option 2: Soak in hot water + dish soap for 20 minutes
• Option 3: Soak in equal parts food-grade hydrogen peroxide and water for 5 minutes to 24 hours

Drying: Air dry completely before storage

Total cleanup time: Approximately 5 minutes per grow

Silicone Lifespan and Care

Expected lifespan: Months of grow cycles with proper care

Normal wear: May develop cosmetic stains with certain varieties (beets, purple radish) - this doesn't affect performance

When to replace:

• Torn or deeply cut silicone
• Excessive wear or degradation
• Loss of structural integrity

Important note: The silicone contains a fiberglass core for structural support. This is food-safe and normal, but it's another reason to avoid cutting or damaging the sheets.

Replacement silicone sheets available here

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Production Capacity and Cost Analysis

How Much Can You Grow?

Single tray capacity: 2-4 ounces of fresh microgreens per harvest

Growing timeline: 7-14 days from seed to harvest (most varieties)

Family of 3-4: One tray lasts approximately 3-4 days

Monthly production (rotating 3 trays):

• Harvest a fresh tray every 3-4 days
• Approximately 6-8 trays per month
• 12-32 ounces of fresh microgreens monthly

Cost Per Grow (Silicone Method)

Initial investment:

• 7x14 Tray Kit: $32.97
• Seeds for first grow: $5-10

Per-grow costs:

• Seeds: $2-5 per tray
• Electricity (windowsill): $0
• Electricity (grow light, 12 hours/day): $0.10-0.25 per grow
• Nutrients: $0.50-1.00 per grow
  

Total per tray: $2.50-6.00 depending on variety and setup

Cost per ounce: Approximately $1.00-1.50

Grocery store comparison: Organic microgreens cost $25-40 per pound ($4-6 per ounce)

Savings: 70-85% compared to store-bought organic microgreens

Cost Per Grow (Soil/Coco Method)

Per-grow costs:

• Seeds: $2-5 per tray
• Soil or coco coir: $1.50-2.50 per tray
• Electricity: $0.10-0.25 per grow
• Nutrients (coco only): $0.50-1.00 per grow

Total per tray: $4.00-8.00

Cost per ounce: Approximately $1.50-2.50

Note: Silicone method becomes more economical after just 2-3 grows since the medium is reusable.

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Troubleshooting Common Issues

Mold Growth

Causes:

• Overwatering
• Poor air circulation
• Too much humidity during germination

Solutions:

• Reduce misting frequency
• Don't leave water pooling on seeds or medium
• Position near gentle airflow (not direct fan)
• Remove humidity dome earlier if mold appears

Seeds Not Germinating

Causes:

• Old or low-quality seeds
• Insufficient moisture
• Too much weight on seeds
• Wrong temperature (too cold)

Solutions:

• Use fresh, quality seeds from reputable suppliers
• Mist more frequently during germination
• Check that dome is making contact but not crushing seeds
• Keep in room temperature area (65-75°F ideal)

Weak, Leggy Growth

Causes:

• Left in humidity dome too long
• Insufficient light
• Overcrowding (too many seeds)

Solutions:

• Remove from dome as soon as plants are 1-2" tall
• Move closer to light source or add grow lights
• Reduce seeding density next grow

Yellow or Brown Leaves

Causes:

• Nutrient burn (too much fertilizer)
• pH imbalance
• Overwatering

Solutions:

• Reduce fertilizer concentration
• Check and adjust pH to 5.5-6.5 range
• Let medium dry slightly between waterings

Root Growth Issues

Causes:

• Inconsistent watering
• Water level too high or too low
• Contaminated growing medium

Solutions:

• Maintain consistent water level in reservoir
• Water should just touch bottom of mesh tray
• Properly sanitize medium between grows

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Frequently Asked Questions

Can I grow microgreens in this kit without grow lights?

Yes! "We don't have grow lights—we just use the tray on a window sill—and even though the grows do take a bit longer, they still produce excellent results." — Customer Review

Place the tray on a bright windowsill (south-facing is best). Grows will take a few days longer than with artificial lights, but results are still excellent. Rotate the tray daily for even growth.

How many kits do I need for continuous harvests?

For a family of 3-4, we recommend starting with 2-3 kits. This allows you to:

• Start a new tray every 3-4 days
• Always have fresh microgreens ready
• Rotate different varieties

"I plan on purchasing 4 more of these trays once my new grow lights and shelving arrives so we can have a more constant variety of veggies in our household." — Customer Review

Can I grow sprouts in this kit?

Yes! The kit works great for sprouts as well as microgreens.

"So far I've used it to grow pea shoots and melon microgreens but also mung bean and urad dal sprouts, as well as a flat of Timothy hay for our guinea pigs to enjoy." — Customer Review

Do I need to use the silicone sheets or can I just use soil?

You can use either! The kit includes two silicone sheets, but the trays work perfectly with soil or coco coir if you prefer traditional growing. Many growers keep both options available and choose based on the variety or their schedule.

How long will the silicone sheets last?

With proper care and cleaning, the silicone sheets can last for months. "I don't see them wearing out anytime soon but it's nice to know I have a second just in case and can swap them out as I see fit." — Customer Review

Can I stack multiple kits?

Yes, the trays are designed to stack efficiently for storage. However, during growing, each kit needs its own space under light. Many growers use simple wire shelving to create a multi-level growing system with multiple kits.

Is this kit good for beginners?

Absolutely! This is our most popular kit for first-time growers specifically because it's simple, forgiving, and includes everything except seeds.

"This tray was my first step into the microgreen world... The setup is very easy, and watching OTG videos helped take the guesswork out of how much seed and water to use." — Customer Review

What varieties grow best in this kit?

Easiest for beginners:

• Broccoli
• Radish
• Mustard
• Kale

Great after you have a few grows under your belt:

• Peas
• Sunflower
• Arugula
• Cilantro

More advanced:

• Basil
• Beets
• Amaranth

Some seeds are NOT compatible with the silicone reusable grow medium, learn more here: Which Microgreen Seeds Work on Reusable Grow Mediums?

Download our free variety guide for complete seeding rates and growing tips.

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Tips from Experienced Growers

"Check Water Every 2-3 Days, Not Daily"

"My work schedule fluctuates drastically from day to day so being able to simply check the water every 2-3 days is great. I don't have that option with the green trays and the plants would ultimately suffer due to my laziness and forgetfulness." — Customer Review

The reservoir system is forgiving. Once you get the hang of how much water your specific varieties drink, you can check every 2-3 days instead of hovering over your trays daily.

"The Reversible Dome is Genius"

Multiple customers mention the clever design of the dome serving double duty:

• Upside down: Weighted germination cover
• Right-side up: Humidity dome for stretching

"The reversibility of the humidity dome that can temporarily hold a mesh tray full of growing microgreens without crushing the roots during water changes" is particularly useful during maintenance.

"Start with Easy Varieties"

Don't try to grow everything at once. Start with broccoli or radish - they're fast, reliable, and forgiving. Once you've had success with the basics, branch out to more challenging varieties.

"These Make Great Gifts"

"I haven't just been recommending this kit to friends—I've been gifting it!" — Customer Review

The 7x14 kit is the perfect gift for health-conscious friends, foodies, or anyone interested in growing their own food. The beautiful white trays look great on countertops, and the complete system means they can start growing immediately.

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Next Steps: Start Growing Today

The 7x14 On The Grow Microgreen Tray Kit makes growing fresh, nutritious microgreens at home achievable for anyone—even if you've never grown anything before.

What You Need to Get Started:

✓ 7x14 Tray Kit - Everything except seeds
✓ Microgreen seeds - Start with broccoli or radish
✓ Light source - Bright windowsill or grow light
✓ Spray bottle - For misting seeds
✓ pH test kit (optional) - For optimal nutrient uptake

Helpful Resources:

• Watch our complete video tutorial
• Download free seeding guide
• Enroll in Microgreen Masterclass for in-depth training
• Browse our YouTube channel for variety-specific guides
• Join our Facebook community

Ready to Upgrade Your Setup?

• Browse replacement silicone sheets
• Shop microgreen seeds
• View our full Amazon storefront

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"Having the ability to grow our own microgreens is a joyful experience and I don't think I would have ultimately pulled the trigger if it wasn't for this tray. OTG is an amazing small company and each order I have received from them has had a personalized handwritten note in it. These guys have treated me better than any other company I know." — Customer Review

We can't wait to see what you grow!

-CJ & Mandi

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Published: May 31, 2023
Updated: January 28, 2026
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