How to Grow Red Pak Choi Microgreens at Home Using a Mini Kratky Tray Setup

August 21, 2025

Curious about growing microgreens at home? Red Pak Choi microgreens—sometimes called Chinese Cabbage or Asian Greens—are a quick, flavorful, and nutrient-packed option that’s perfect for beginners and experienced growers alike. In this guide, we’ll show you how to use and create a simple DIY mini Kratky Tray setup to grow your own Red Pak Choi microgreens with minimal effort. By the end, you’ll know exactly how to set up your trays, germinate your seeds, care for your microgreens, and harvest a fresh, vibrant tray in just nine days using hydroponic growing methods.

Supplies List

To create this DIY mini Kratky Tray setup, you’ll need the following items:

Deep Sprouting Tray Set – use the green no-holed tray
Large Sprouting Tray Set – use one green tray and one white mesh tray
OR we now sell a pre-made kit that can be purchased here!

To grow Pack Choi Microgreens with this setup, you’ll need the following items:

Silicone Reusable Grow Medium
Red Pak Choi Microgreen Seeds – 15 grams per Large Sprouting tray
Pump-Style Sprayer
Fertilizer water (amount depending on tray size, approximately 9 cups for mini setup)
LED Grow Lights OR well lit window for natural light
Optional: 10x20 Kratky Tray Kit for larger setups

Step-by-Step Instructions

Step 1: Setting Up the Trays

Start by assembling your mini Kratky Tray setup. Place the white mesh tray from your Large Sprouting Tray Set on top of the green no-holed tray from your Deep Sprouting Tray Set. This combination creates a deeper reservoir for the water, allowing your microgreens to thrive without daily bottom-watering later in the grow.

Next, lay a single sheet of Silicone Reusable Grow Medium in the large sprouting tray size flat on top of the mesh tray. This prevents seeds from falling through the holes while supporting healthy root growth.

Step 2: Seeding

Measure 1 ½ tablespoons (approximately 15 grams) of Red Pak Choi Microgreen Seeds. Mist the reusable medium lightly with water using a pump-style sprayer to help seeds stick. Evenly spread the seeds across the tray, avoiding large clumps for consistent germination.

Step 3: Initial Watering and Humidity

Mist the seeds with water for 7–9 seconds to begin germination. Place the other no-holed large sprouting tray on top to trap humidity, creating a mini greenhouse effect. Check later in the day and mist again if needed.

Step 4: Day 3 – First Signs of Germination

By the morning of day three, you’ll notice some seeds starting to crack open. Give them their first watering of the day before returning them to the germination setup. Continue misting two times per day or as needed.

Step 5: Day 4 – Sprouting and Blackout Preparation

By day four, the microgreens should have sprouted evenly, with roots starting to poke through the bottom of the mesh tray. Mist the tray to keep everything hydrated. Flip the top tray to create a blackout dome, keeping the microgreens in darkness to encourage uniform growth. Check again later that same day and mist the tray a second time.

Step 6: Day 5 – Transition to Light

Remove the blackout dome. Your microgreens should now have reached an even height with plenty of roots showing. Pour out any old water from the bottom tray collected during germination. Fill the deep tray with about 9 cups of fertilizer water, ensuring roots make contact without flooding the medium or tray above.

Place the trays under your light source, such as three 20W LED lights on a shelf, or a well-lit window for natural light. From here, the microgreens largely take care of themselves.

Step 7: Days 5–8 – Minimal Maintenance

Check that the roots remain in contact with the water daily. There’s usually no need to add more water, thanks to the deep bottom tray. If water develops a stagnant smell or foggy appearance, refresh it to maintain plant health. If the root area looks dry, add more water.

Step 8: Day 9 – Harvest

Your Red Pak Choi microgreens are ready to harvest! Before cutting, pour out the water in the bottom tray. Using scissors or a sharp knife, harvest the microgreens at the base, leaving any unneeded roots behind. This mini Kratky Tray setup allows you to grow around 100 grams of Red Pak Choi microgreens from just 15 grams of seed in nine days.

Person holding a tray with microgreens above a green and white tray on a countertop.

Growth Tips

Mist lightly as needed during germination to maintain humidity.
Monitor root contact with water; adjust fertilizer water levels if roots appear dry.
Lighting is flexible; LEDs speed up growth, but bright natural light works well.
Watering frequency can vary depending on room temperature, humidity, and crop type.
Avoid over-watering to prevent root rot or mold growth.

Harvesting Instructions

Harvest when microgreens start to show sign of true leaves.
Use clean scissors or a knife to cut at the base.
Pour out any old water in the bottom tray before harvesting.
Handle microgreens gently to avoid bruising.
For longer storage, keep harvested microgreens in a sealed container in the fridge.

Flavor, Appearance, & Uses

Red Pak Choi microgreens have a egg-like flavor with a mild, spicy undertone, similar to kale, cabbage, and broccoli microgreens. They add a fresh, crunchy texture to dishes. Use them in:

Spring rolls
Salads and wraps
Sandwich and burger toppings
Garnishes for soups and bowls

Visually, the bright green leaves with tender red stems make them an appealing addition to any plate.

Fun Facts

Red Pak Choi microgreens grow exceptionally fast, maturing in just nine days.
They require minimal daily maintenance thanks to the Kratky tray reservoir.
The small tray setup is ideal for home growers with limited space.

Harvest Cleanup & Medium Reuse

After harvesting:

Use a scraper tool to remove leftover roots and stems from the reusable medium. Start with the root side if roots are dense.
Wash and sanitize the Reusable Medium thoroughly.
The medium can be sanitized with boiling hot water or steam.
Once cleaned, the medium can be reused multiple times.
Compost leftover roots and stems to reduce waste.

Final Thoughts

This mini Kratky Tray setup demonstrates how simple and low-maintenance growing Red Pak Choi microgreens at home can be. With minimal daily effort, you can enjoy fresh, vibrant microgreens in just nine days. Whether you’re short on space or busy with other tasks, this setup makes home microgreen growing almost effortless.

If you’d like to try it yourself, you can find both the Deep Sprouting Tray and Large Sprouting Tray sets here on our website: www.onthegrow.net. These tray kits are perfect for home growers. For those looking for a larger sized Kratky Tray Kit for Microgreens, the 10x20 Kratky Tray Kit is ideal for your setup.

Grow Red Pak Choi Microgreens - On The Grow