1. Introduction

At Grow Sow Greener UK, we believe that growing your own food isn’t just a hobby—it’s a step toward a healthier, more sustainable world. Our mission is simple: to empower as many people as possible to cultivate their own fresh, nutritious produce, no matter their space, experience, or resources.

Rambo Radish Microgreens, a vibrant and flavorful addition to your culinary and nutritional repertoire. These organic, GMO-free, and untreated heirloom seeds sprout into microgreens with striking deep purple stems and leaves, occasionally tinged with green, making them a visual standout in any dish. Beyond their aesthetic appeal, Rambo Radish microgreens are celebrated for their zesty, fresh, and spicy flavor, adding a delightful kick to salads, sandwiches, soups, and more.

One of the quickest and easiest varieties to cultivate, Rambo Radish microgreens can be harvested as early as day 7, or allowed to reach the true leaf stage for a more substantial crop. Their big peppery leaves and crunchy robust stems make them a favorite among home growers and chefs alike. Nutritionally, they are a powerhouse, packed with vitamins A, B, B6, C, E, and K, as well as folic acid, iron, phosphorus, potassium, calcium, magnesium, zinc, carotenes, pantothenic acid, and a good source of fiber.

Cultivating these microgreens is straightforward with a harvest window between 8-11 days. The seeds are pathogen-tested and packaged in 100% compostable, resealable, and plastic-free materials, great for both your health and the planet.

This guide is crafted for both professional and home growers and details every step of the process using our specialized tray systems.

2. Rambo Radish Microgreens: Variety Overview & Health Benefits

Key Features:

• Latin Name: Raphanus sativus
• Certified Organic: Yes
• Seed Treatment: Untreated and lab‐tested for pathogens
• Flavor & Texture: Peppery, Zesty, fresh, spicy.

Nutritional Benefits:

• Vitamins A, B, B6, C, E & K, folic acid, iron, phosphorus, potassium, calcium, magnesium, zinc, carotenes, pantothenic acid, and a good source of fibre.
• Rich in antioxidants – Packed with vitamins A, C, and E, these microgreens help combat oxidative stress, reducing inflammation and supporting overall cellular health.
• Boosts digestion and gut health – High in fiber, Rambo Radish microgreens promote healthy digestion, improve gut microbiome balance.
• Enhances immunity – The combination of vitamins B6, C, and zinc strengthens the immune system, aiding in faster recovery and better defense against illnesses.

3. Equipment & Materials

3.1 Tray Systems Overview

We offer two specialized tray systems designed for your growing scale:

• 1122 Tray System (Professional-Grade and size):
  • Usage: Ideal for urban vertical farms and professional growers.
  • Design: A three-tray system consisting of:
    • A bottom reservoir tray that holds water for bottom watering.
    • A growing tray with holes for filling with compost.
    • A top reservoir tray that serves as a cover.
  • Functionality:
    • The bottom tray delivers water via capillary action through the holes in the growing tray.
    • The top tray creates a blackout/humidity dome, ensuring even moisture and optimal germination.
  • Dimensions: 56cm x 28cm x 3cm (22" x 11" x 1 3⁄8")
  • Materials: BPA-free recycled food grade PP; heavy-duty injection moulded
  • Weight: 350g per tray
• Home Professional Tray Set (For Part-Time and Home Growers):
  • Usage: Ideal for home growers and what I use to feen the family, this tray set fits neatly on windowsills and counters, with a 6cm depth that retains moisture better than larger commercial trays, ensuring simpler, hassle-free harvests and you can fit a wider range of microgreens in your space.
  • Design: Comprised of three BPA-free, recycled plastic trays made in England that mimic commercial growing techniques in a compact size.
  • Dimensions: 22cm x 17cm x 6cm
  • Materials: BPA-free recycled food grade PP; heavy-duty injection moulded
  • Weight: 104g per tray
  • Drainage: Two-tiered drainage holes for optimum moisture control
  • Capacity & Setup:
    • Bottom Tray Capacity: 1200ml
    • Use 1 × 10cm coco discs with 400ml water or half a 650g coco brick to fill the trays perfectly.
  • Key Benefits:
    •  The trays 6cm depth (as opposed to the 3cm depth of the professional system) helps maintains consistent moistureand carefree maitenance, making it nearly “bomb-proof” for part-time growers who are more susceptible to miss a watering.
    • Enables cultivation of a wide variety of microgreens in a compact, user-friendly system.

3.2 Seeding Rates & Container Guidelines

• Home Professional Tray Set: Recommended seeding density is 6g of organic rambo radish microgreen seeds per tray.

  A sparser seeding rate produces larger leaves, which I and many home growers prefer whilst a heavy seeding rate will result in a crop with a higher proportion of stems to leaves.

• 1122 Tray System (Professional): Recommended seeding density is 25g of purple radish microgreen seeds per tray.

  Heavier seeding results in more stems with smaller leaves, which may be advantageous when growing for weight in a commercial setting.

• Important Considerations: The provided weights (6g and 25g) are on the safer side to manage humidity and reduce crop failure risks.

  You can of course choose to sow more heavily if you can optimize environmental controls such as airflow, temperature, and humidity.

  Heavier seeding may increase mold risk however commercial cultivators seed considerably heavier

3.3 Vertical Growing & Rack Setup

Growing microgreens vertically saves space and allows for year-round production with LED lighting. Here’s how to set up an efficient vertical rack system for optimal growth or your radish microgreens.:

• Choosing Your Rack:
  • Use sturdy, vertical shelving (such as kitchen wire-style racks) that allow for easy cleaning, excellent airflow, and efficient light distribution.
  • The ideal rack size is 122cm wide and 45cm deep, perfectly fitting four 1122 trays per shelf.
  • Ensure your rack setup matches your tray dimensions to maximize growing space and each shelf is perfectly level to avoid dry (and waterlogged sections in your growing trays)
• Rack Dimensions & Configuration:
  • Standard Rack Size: 122cm (width) x 45cm (depth)
  • Shelves: Typically 6 adjustable shelves per rack.
  • Tray Capacity Per Shelf: 4 trays; with 6 shelves, a rack can hold up to 24 trays.
• LED Lighting Setup:
  • Recommended: Two Barrina LED grow lights per shelf (or two Arize lynk LED for professional setups).
  • Installation: Space lights evenly to cover all trays.
  • Spacing & Positioning:
    • Shelves should be evenly spaced for optimal light and airflow.
    • The distance between the LED lights and the microgreens should be around 20–30cm for optimal light penetration and balanced growth.
    • Position warm climate crops such as Basil higher on the racks and don’t be afraid to utilise a heat mat. Colder loving varieties such as red mustards and Red Kales (napus) should be positioned lover in the racks where the environment will be naturally colder.
• Environmental Optimization:
  • Air Circulation: Use a small oscillating fan to keep air moving and minimize the risk of mold, particularly at higher seeding densities.
  • Temperature Control: Maintain a room temperature of 18–24°C with 50% relative humidity for optimal microgreen growth.

4. Growing in Soil Using Our Tray Systems

Step 1: Preparing Your Growing Container

• Selecting the Tray:
  • Home Growers: Choose the Home Professional Tray Set for its compact size and excellent moisture retention. (Two reservoir, one growing tray)
  • Professional Growers: Use the 1122 Tray System to maximize yield with bottom watering. (Two reservoir, one growing tray)
• Container Preparation: Ensure the tray is clean and free of residues before adding compost, coco, or a grow mat.

Step 2: Soil Preparation

• Choosing Your Medium: Use high-quality coco coir, grow mats, or a nutrient-rich compost mix designed for seed starting. I prefer coco coir as its consistent, easy and small to store and the texture is always perfect for new roots. Always ensure your coco is LOW “EC” which has been cleaned of its salt content.
• Hydrating Coco Coir:
  1. Unpack & Place: Remove the compressed coco coir block from its packaging and place it in a large bucket or container – it will expand more that you think!
  2. Add Lukewarm Water: Slowly pour lukewarm water (about 20–30°C) over the block. The hotter the faster but safety first!
  3. Soak & Expand: Let it soak for 15–30 minutes until it expands and softens.
  4. Fluff: Break up any clumps and fluff the coir until it has an even, light texture.
  5. Mix Nutrients: Stir in organic trace minerals and seaweed powder to enrich your medium. I prefer our sea fert powder as its gentle organic and i dont have to measure or dose it out like a chemical fert which can burn our seedlings (For more details, click here.)
• Filling the Tray: Fill your tray to the rim of whatever container your using with the prepared medium before sowing your microgreen seeds. This helps with airflow and also efficient harvesting and is really highly recommended. Ggently tamp down before sowing your seeds. Your coco or compost should be damp but not waterlogged or soggy.

Step 3: Sowing the Seeds

• Measuring & Distributing:
  • For the Home Professional Tray Set: Use approximately 6g of radish seeds per tray.
  • For the larger 1122 Tray System: Use approximately 25g of organic microgreen seeds per tray.
• Sowing Technique: Evenly spread the seeds over the soil surface, ensuring each seed is spaced approximately one to two seed lengths apart. Imagine poppy seeds on top of a bun. Note: Heavier seeding increases humidity within the tray, which may raise the risk of mold and crop failure if environmental controls aren’t optimized. Additionally, heavier seeding typically produces more stems and smaller leaves. The recommended weights provided here are on the sparser, safer side—but growers may choose to sow more heavily if they can keep conditions (airflow, temperature, humidity) strictly controlled.

Step 4: Establishing a Humid Environment and Stacking Procedure

1. Initial Misting: Gently mist the seeds with a spray bottle to settle them into the compost.If you spay vertically downwards you can actually force the seeds further into contact with the growing media.
2. Assembling the Three-Tray System:
   • Bottom Reservoir Tray: This tray provides bottom watering through capillary action. Fill the bottom reservoir tray with water only once your microgreens have germinated and have begun to grow.
   • Growing Tray: Place the growing tray (with holes and filled with compost to the rim) directly into the bottom reservoir tray.
   • Top Reservoir Tray: Stack the second (top) reservoir tray over the growing tray. Lay it straight on top of the seeds, the right way up, pushing them into the compost. This top tray serves as a cover, creating a blackout environment that retains humidity and warmth essential for seed germination.
3. Applying Weight for an Even Canopy: Place a clean, heavy object (e.g., canned goods) on top to force roots into the compost and a satisfyingly even canopy. Dont be afraid of this step, commercial growers use pavers or bricks, your microgreens are stronger than you think!
4. Blackout and Stretch: You will find a lot about this on youtube and other grow blogs about this step. Im a firm believer this is unnecessary, confusing and overcomplicates the simple process of keeping a few plants alive for a week or two. (which in effect is all microgreen growing is).

   Without proper environmental controls, this step can increase the chance of crop failure due to humidity related issues. I never do this when growing for the family, just leave the lights off an extra day or two if you really want nice long stems…. Keep it simple stupid!!

   For our commercial customers… You know the processes and blackout timings per crop tailored to your specific grow rooms environment better than I can guess so wont be commenting on blackout here either.

   (Optional) Leave lights off extra days to encourage stem elongation however only uncover from weight once your microgreens have actually lifted the top tray. They will look yellow and sickly however will soon colour up with exposure to light. This is normal!!

5. Maintaining Environmental Conditions:
   • Keep relative humidity around 50% and temperature between 18–24°C.
   • Use a fan to move air around the grow room. Good airflow minimizes the chance of mold while ensuring a consistent environment. This can be via clip on fans on your racks or a larger oscillating pedestal or ceiling fan

Step 5: Light Exposure & Growth Management

• Light Requirements: Once germination occurs (typically within 1–3 days), remove the cover and expose your microgreens to bright, indirect light or use LED grow lights. If you prefer a bit more stem (still delicious) leave dark for a few days until they etiolate or stretch.
• Airflow & Temperature: Maintain gentle airflow and stable temperatures (18–24°C) to prevent mold and promote growth.
• Rotation: Your microgreens will lean towards the light source. If windowsill growing periodically rotate the tray to ensure even light distribution and vertical growth.
• Misting and Care: Mist generously until germination; thereafter, water only via the bottom reservoir and only when needed, this keeps your greens dry and healthy whilst providing water to the root system only.

Imagery/Video Guidance:

• Video: A time-lapse video documenting growth under proper lighting conditions.

Step 6: Harvesting & Post-Harvest Handling

• Harvest Timing: Harvest your microgreens when they reach full colour and optimal size. (typically 7–11 days) Microgreens are usually harvested before the first true leaves appear when they are their most succulent, juicy and sweet.
• Cutting Technique: Use clean, sharp scissors or a knife to cut just above the soil level. with your other hand keep hold of the canopy and place in your prepared container.
• Post-Harvest Care: Store harvested microgreens in an airtight container in the fridge and avoid excess moisture. Dont immediately wash your microgreens, rather refridgerate first and only wash before consumption

Imagery/Video Guidance:

• Photo: A series of images capturing the harvesting, rinsing, and drying stages.
• Video: A detailed tutorial on proper harvesting techniques and post-harvest care.

5. Tray Systems: In-Depth Product Details

5.1 1122 Tray System for Professional Growers

• Design:
  • Bottom Reservoir Tray: Holds water for bottom watering; water wicks upward uniformly.
  • Growing Tray with Holes: Sits atop the reservoir and is filled with compost.
  • Top Reservoir Tray: Covers the growing tray, creating a blackout/humidity dome.
• Key Features:
  • Dimensions: 56cm x 28cm x 3cm (22" x 11" x 1 3⁄8")
  • Materials: BPA-free recycled food grade PP; heavy-duty injection moulded
  • Weight: 350g per tray
  • Additional Uses: Ideal for bottom watering and integration with automated systems.
• Benefits: Ensures uniform moisture distribution and optimal germination, designed for repeated use in professional or urban vertical farms.

Imagery/Video Guidance:

• Photo: Detailed product images from multiple angles highlighting the three-tray configuration.

5.2 Home Professional Tray Set for Part-Time Growers

• Design & Features:
  • Comprised of three BPA-free, recycled plastic trays made in England.
  • Dimensions: 22cm x 17cm x 6cm
  • Materials: BPA-free recycled food grade PP; heavy-duty injection moulded
  • Weight: 104g per tray
  • Drainage: Two-tiered drainage holes for optimal moisture control
• Setup Details:
  • Bottom Tray Capacity: 1200ml
  • Use one 10cm coco disc with 400ml water per disc or half a 650g coco brick to fill the trays.
• Key Benefits: A commercial sized microgreen growing system for larger harvests. The growing tray (with holes) can be used separately in large scale flood and drain tables or other hydroponic systems.

Imagery/Video Guidance:

• Photo: Lifestyle images of the Home Professional Tray Set in a home kitchen or on a windowsill.
• Video: A comprehensive setup and review emphasizing ease of assembly and durability.

6. Advanced Tips & Best Practices

• Optimizing Seeding Density: Use about 25g per tray for the 1122 system and 6g per tray for the Home Professional Tray Set, or 0.017 g per cm² for recycled containers.
• Harnessing Bottom Watering: Leverage the reservoir design for uniform moisture without overwatering.
• Light & Temperature Management: Use LED grow lights and maintain 18–24°C to for optimum growth.
• Maintaining Optimal Humidity: Aim for around 50% relative humidity to balance moisture and airflow.
• Air Circulation: Use a fan to promote even airflow and reduce mold risks.
• Nutrient Boost: Consider adding organic trace minerals or seaweed powder when prepping trays or as a liquid feed after seed leaves open.
• Experimentation: Optionally, try a blackout period (2–3 days) to assess its effect on stem length and yield.

Insights from Video Reviews: One video emphasizes an efficient stacking procedure that forces roots into the compost by drawing water upward from the bottom reservoir.

7. Common Issues & Troubleshooting

1. Mold & Fungal Growth
   • Mold and fungi thrive in moist, stagnant environments and can compromise the health of your microgreens.
   • Prevention:
     • Air Circulation: Utilize a small oscillating fan to promote airflow, reducing humidity and deterring mold growth.
     • Humidity Control: Maintain relative humidity around 50%. Avoid overwatering, as excessive moisture creates a conducive environment for mould.
     • Sanitation: Sterilize trays and equipment before each use to eliminate potential contaminants.
   • Identification: Root Hairs vs. Mold: It's common to mistake healthy root hairs for mold. Root hairs appear as fine, white fuzz near the seed and root area and are a normal part of plant development. In contrast, mold often presents as a more extensive, web-like growth covering seeds and soil. To differentiate, gently mist the area with water; root hairs will disappear temporarily when moistened, while mold remains unaffected
   • Remediation:
     • Targeted Removal: If mould is localized, carefully remove the affected sections to prevent spread.
     • Antifungals: Apply a mild solution of hydrogen peroxide (1-3% concentration) to the affected area to inhibit mold growth. Cinamon powder can also be used however check its allergen status if selling your produce.

       This can also be applied to the seeds and growing medium when sowing as a bit of a prophylactic however I don’t recommend it unless you know your seed or compost has a mould problem.

       Some growers hit their peas and sunflower seeds as a prophalactic however I find this can actually speed up the decomposition of the outer husk, basically preparing a nice ready to go dinner for mould.

2. Uneven Germination
   • Seed Quality: Use fresh, high-quality seeds from reputable suppliers like Grow Sow Greener to ensure high germination rates.
   • Even Distribution: Sow seeds uniformly across the tray to promote consistent growth.
   • Stacking Period: Maintain a weighted cover during the initial 2-3 days of germination to encourage even root development and sprout emergence.
   • Level surface: Ensure your trays are completely level, this avoids waterlogged and dry sections in your growing trays.
3. Leggy or Weak Growth
   • Adequate Lighting: Provide consistent light exposure using LED grow lights positioned 20–30 cm above the trays. Ensure the windowsill recieves enough light.
   • Light Duration: Ensure microgreens receive 12-16 hours of light daily to support robust growth.
   • Tray Rotation: Rotate trays daily to ensure even light distribution and prevent plants from leaning towards the light source.
4. Pest Issues(pretty rare when growing inside)
   • Clean Growing Medium: Use sterile, high-quality soil or growing media to minimize pest introduction. Never soil dug from the garden.
   • Sanitation: Clean and disinfect all equipment and surfaces between growing cycles.
   • • Inspection: Regularly inspect plants for signs of pests such as aphids or mites.
   • Natural Deterrents: If pests are detected, apply natural remedies such as neem oil or insecticidal soap, following manufacturer instructions. Yellow sticky traps can also be used.
5. Overwatering & Underwatering
   • Overwatering: Look for yellowing leaves and soggy medium.
   • Solutions: Allow the soil surface to dry slightly between waterings. Ensure trays have proper drainage to prevent water accumulation.
   • Underwatering: Look for wilting and dry soil.
   • Solutions: Establish a regular watering schedule, ensuring the growing medium remains consistently moist but not waterlogged. You will get a feel for the correct weight of your trays after a few grows!!It is far easier to rectify an underwatered crop. Even if your microgreens have fallen completely over, after a drink and a few hours theyll be back to their old selves!.
6. Nutrient Deficiencies
   • While microgreens require minimal nutrients due to their short growth cycle, deficiencies can occur, especially if using coir growing media for longer cycle crops (+ 2 weeks) such as some of the herbs. You may notice growth slowing or stopping, yellowing or discolouration of leaves and a poor yeild
   • If deficiencies occur, Use a nutrient-rich, sterile growing medium for each planting cycle or apply a diluted organic fertilizer as directed.
7. Contamination Risks
   • Practice strict hygiene when handling seeds and microgreens.
   • Use clean, potable water for irrigation.

8. Nutritional Profile & Health Benefits

All radish microgreens are packed with nutrients, making them an excellent addition to a healthy diet:

• Vitamin A: Supports vision, immune function, and cell growth.
• Vitamin B6: Aids brain function, red blood cell production, and immune support.
• Vitamin C: Essential for skin health, immune defense, and antioxidant protection.
• Vitamin K: Aids in blood clotting and supports strong bones.
• Calcium: Supports bone health, muscle function, and nerve signaling.
• Iron: Essential for oxygen transport and preventing fatigue.
• Magnesium: Helps with nerve function, muscle relaxation, and energy production.
• Chlorophyll: Provides detoxifying properties and supports oxygenation in the body.
• Antioxidant Properties: Rich in vitamins C and E, helping to combat oxidative stress.
• Supports Cardiovascular Health: Potassium and antioxidants help regulate blood pressure and reduce inflammation.

Adding radish microgreens to your diet boosts nutrition while enhancing meals like salads, sandwiches, and smoothies with fresh flavor and powerful health benefits..

9. Seed Quality & Sourcing

The success of your microgreen crop starts with high-quality seeds. Consider the following:

• Where to Buy Quality Seeds: Purchase from trusted sources like Grow Sow Greener—known for lab-tested, pathogen-free, high-germination-rate seeds.
• Factors to Consider: Look for seeds with at least an 85% germination rate, ensure purity, and confirm they are lab-tested.
• Storage Recommendations:
  • Store seeds in a cool, dark, and dry place in an airtight container.
  • For long-term storage, refrigerate or freeze unopened packets (note: frequent opening can reduce viability).

10. Culinary Uses & Recipe Ideas

Flavor & Texture:

• Taste: Mild, sweet, and nutty—ideal as a healthy neutral base.
• Texture: Crisp and refreshing; perfect for raw dishes or light cooking.

Serving Suggestions:

• Savory Breakfast Bowl – Top a warm quinoa or brown rice bowl with a fried egg, avocado slices, crumbled feta, and a handful of radish microgreens for a nutrient-packed start to the day.
• Creamy Microgreen Hummus Wrap – Spread hummus on a whole-wheat tortilla, layer with shredded carrots, cucumber slices, and radish microgreens, then roll it up for a fresh, crunchy wrap.
• Spiced Roasted Veggie Bowl – Roast sweet potatoes, chickpeas, and zucchini with a dash of cumin and paprika, then toss with a lemon-tahini dressing and a generous handful of radish microgreens for a bold flavor boost.

Recipe Idea – Rambo Radish Microgreens & Citrus Prawn Salad

1. Ingredients: This refreshing salad combines the peppery bite of Rambo Radish microgreens with sweet citrus and creamy avocado. Toss 2 cups of microgreens, ½ lb cooked prawns, 1 segmented grapefruit or orange, ½ sliced avocado, ¼ small red onion, and ¼ cup toasted almonds in a bowl. Whisk 1 tbsp olive oil, 1 tbsp lime juice, ½ tsp honey, salt, and pepper, then drizzle over the salad. Light, flavorful, and nutrient-packed, this dish is perfect for a fresh, satisfying meal.
2. Instructions: For extra creaminess, add one tablespoon of crumbled feta or goat cheese..

Imagery/Video Guidance:

• Photo: A beautifully plated salad featuring radish microgreens.
• Video: A complete recipe tutorial from ingredient prep to final plating.

11. FAQs About Organic Broccoli Calabrese Microgreens

Q: How long does it take to grow rambo radish microgreens in the UK?

A: They are typically ready for harvest between 7–11 days when grown in soil or coco using our tray systems.

Q: What seeding rate should I use?

A: Approximately 6g per tray for the Home Professional Tray Set and 25g per tray for the 1122 Tray System. For recycled containers, aim for 0.02 g per cm².

Q: Which tray system should I choose?

A: It depends on your scale—Home Professional for compact, home use and the 1122 Tray System for professional or urban vertical farming.

Q: How do I ensure proper moisture without overwatering?

A: Use bottom watering—add water when the bottom reservoir is dry, and avoid overwatering by monitoring tray weight. Dont water untill well afeter germination

Q: What environmental conditions are optimal?

A: For larger setups, maintain 18–24°C and about 50% relative humidity with proper airflow.

12. Conclusion & Next Steps

Rambo Radish microgreens are an easy, nutrient-packed addition to any meal, offering vibrant color, crisp texture, and a peppery kick. More than just a garnish, they are rich in vitamins, antioxidants, and essential minerals, supporting a healthy diet. At GrowSowGreener, we believe in sustainable, homegrown food that reduces waste and supports a greener planet. Growing your own microgreens is a simple yet impactful way to embrace fresh, eco-friendly eating.

Next Steps:

• Choose your organic seeds, the tray system and growing media that best fits your growing needs.
• Follow the detailed steps to prepare, sow, and nurture your microgreens.
• Experiment with advanced techniques to optimize yield and flavor.
• Enjoy our recipe ideas and share your successes with our growing community!

Imagery/Video Guidance:

• Photo: An inspiring final image of a bountiful tray of organic broccoli microgreens ready to be enjoyed.
• Video (Optional): A closing message featuring community feedback and user success stories.