Microgreens are young edible plants grown densely in trays and harvested soon after germination. They are quick to grow, need very little space and can be produced indoors, on a windowsill, on a balcony, in a greenhouse or under grow lights.
The basic method is simple: prepare a tray, add a suitable growing medium, sow at the correct density, provide the appropriate covered or blackout period, introduce light after germination, water carefully and harvest when the crop reaches the right stage.
The important part is that different microgreens need different treatment. Broccoli and radish are very different from peas, sunflower, basil or coriander when it comes to soaking, seeding density, blackout, watering and harvest time.
This guide explains how to grow microgreens in Australia, from choosing seed and trays through to lighting, watering, harvesting and troubleshooting.
Microgreens: Quick Start
| Best beginner crops | Broccoli, radish, mustard and pea shoots |
|---|---|
| Growing medium | Seed-raising mix, coco coir or suitable growing mats |
| Typical medium depth | Approximately 2–4 cm for many crops |
| Light | Bright natural light or suitable grow lights after germination |
| Watering | Surface watering during establishment, then bottom watering once roots develop |
| Typical harvest | Approximately 7–21 days depending on variety |
Looking for microgreen seed?
Seedmart supplies microgreen seeds in packet and bulk quantities for home growers, market gardeners and commercial microgreen production.
In This Guide
- What are microgreens?
- Microgreens vs sprouts
- Best microgreens for beginners
- What you need
- Where to grow microgreens
- How to grow microgreens step by step
- How much seed to use
- Blackout and weighted germination
- Lighting
- Watering
- Choosing trays
- Growing media
- Temperature, humidity and airflow
- Growing and harvest times
- Australian growing conditions
- Troubleshooting
- Harvesting and storage
- Food safety
- Frequently asked questions
What Are Microgreens?
Microgreens are young seedlings of edible vegetables, herbs and other plants. They are harvested after germination but before the plant reaches the baby-leaf or mature stage.
Most are harvested after the cotyledons, or first seed leaves, have opened and developed colour. Depending on the crop, the first true leaves may just be beginning to appear.
Common microgreens include:
- Broccoli
- Radish
- Mustard
- Kale
- Red cabbage
- Peas
- Sunflower
- Beetroot
- Amaranth
- Basil
- Coriander
- Mizuna
- Tatsoi
- Shiso
- Sorrel
These crops differ substantially in seed size, germination speed, soaking requirements and growing behaviour. That is why a single microgreen recipe does not work equally well for every variety.
Microgreens vs Sprouts: What Is the Difference?
| Feature | Microgreens | Sprouts |
|---|---|---|
| Growing method | Usually grown in shallow trays | Usually grown in jars or sprouters without soil |
| Growing medium | Soil, coir or another suitable medium | No growing medium normally required |
| Light | Required after germination | No dedicated growing-light stage normally required |
| Harvest | Stems and leaves are cut above the growing medium | Root, shoot and remaining seed are generally harvested together |
Which Microgreens Are Best for Beginners?
Fast, vigorous varieties are generally easier for a first crop because they germinate quickly and make it easier to learn moisture, blackout, lighting and harvesting.
Broccoli
Fast and reliable. Small seed and normally no pre-soaking required.
Radish
Very fast germination, vigorous growth and a strong peppery flavour.
Mustard
Small seed, quick establishment and generally straightforward to grow.
Pea Shoots
Larger seed and usually pre-soaked, but vigorous once established.
What Do You Need to Grow Microgreens?
A basic microgreen setup does not need to be complicated.
- Microgreen seed: Choose seed suitable for the crop you intend to grow and check treatment information.
- Growing tray: A shallow tray with drainage holes works for most crops.
- Solid lower tray: Useful for catching drainage and bottom watering.
- Growing medium: Seed-raising mix, coco coir or suitable growing mats.
- Water: Use clean drinking-quality water.
- Cover or second tray: Used during germination where required.
- Optional weight: Useful for crops such as peas and sunflower.
- Light: Natural light or artificial grow lighting after germination.
- Harvesting tool: Clean scissors or a sharp harvesting knife.
Where Is the Best Place to Grow Microgreens?
Microgreens can be grown in many different places. The best position is one where you can reasonably control light, temperature, moisture and airflow.
| Location | Advantages | Things to Watch |
|---|---|---|
| Windowsill | Convenient for a small number of trays | Uneven light and heat through glass |
| Kitchen or utility area | Easy access for checking and watering | May need supplemental lighting |
| Indoor shelving | Good control and useful for multiple trays | Requires adequate lighting and airflow |
| Balcony or patio | Good natural light and ventilation | Sun, wind, rain, birds and insects |
| Greenhouse | Protection from rain and some pests | Heat and humidity can build quickly |
| Outdoor growing area | Natural light and airflow | Greater exposure to weather and pests |
Australian growing tip: A sunny windowsill is not automatically the best position. During summer, particularly on west-facing windows, the air and tray temperature behind glass can rise rapidly and stress young microgreens.
How to Grow Microgreens Step by Step
1. Clean Your Equipment
Start with clean trays, covers, soaking containers and harvesting equipment. Remove old roots and growing-medium residue before reusing trays.
2. Prepare the Growing Medium
Add an even layer of suitable growing medium. Approximately 2–4 cm is a practical starting depth for many crops, although peas and sunflower can benefit from a little more root depth.
Moisten the medium evenly before sowing. It should be damp throughout without containing pools of standing water.
3. Check Whether the Seed Needs Soaking
Small seeds such as broccoli, radish, kale and mustard are normally sown dry. Large seeds such as peas and sunflower generally benefit from pre-soaking.
Always follow instructions for the individual crop rather than using one soaking time for every seed.
4. Sow at the Correct Density
Spread the seed evenly across the tray. Microgreens are deliberately planted densely, but excessive seeding can reduce airflow, trap moisture and produce a weak or uneven crop.
5. Establish Good Seed-to-Medium Contact
Seeds germinate more evenly when they remain in close contact with the moist growing surface.
Small seeds may only need light pressure. Larger seeds such as peas and sunflower often benefit from more deliberate weighting during early germination.
6. Cover the Tray During Germination
Many microgreens benefit from covered germination or a blackout stage. This helps maintain moisture, seed-to-medium contact and even establishment.
7. Move the Seedlings into Light
Once the crop has germinated and the roots are established, remove the cover and place the tray in suitable natural or artificial light.
Freshly uncovered seedlings may initially look pale yellow or cream. This is normal after growing without light.
8. Transition to Bottom Watering
Gentle surface watering can be useful during sowing and early germination. Once the roots are established, bottom watering is usually more practical.
Place the perforated growing tray into a solid lower tray and add a modest amount of water beneath the crop. Avoid leaving trays continuously submerged in deep standing water.
9. Maintain Airflow
Dense microgreen canopies can trap humidity. Avoid cramped, stagnant growing areas and continuously wet foliage.
10. Harvest at the Right Stage
Use clean scissors or a sharp harvesting knife and cut the stems just above the growing medium.
Many fast crops are ready in approximately 7–14 days, while slower herbs and speciality microgreens may take several weeks.
How Much Microgreen Seed Should You Use Per Tray?
There is no universal seeding rate for microgreens. The correct amount depends on seed size, tray size and crop growth habit.
A tray of broccoli requires far less seed by weight than the same tray planted with peas or sunflower.
Seeding density depends on:
- Tray dimensions
- Seed size
- Germination percentage
- Crop growth habit
- Growing medium
- Humidity and airflow
- Desired canopy density
The aim is to create an even canopy without allowing large amounts of seed to pile on top of one another.
Related guide: For detailed starting rates for broccoli, radish, peas, sunflower and other crops across common Australian tray sizes, see our Microgreen Seeding Density Chart for Australian Tray Sizes.
Do Microgreens Need a Blackout Period?
Many microgreens benefit from a covered germination period, but not every crop requires exactly the same blackout method.
Depending on the crop, growers may:
- Place another tray directly on top of the seed
- Add light or moderate weight
- Use an opaque cover without significant pressure
- Continue a short period of darkness after the seedlings begin lifting the cover
Peas and sunflower generally tolerate or benefit from more pressure than small-seeded crops such as broccoli or mustard.
Do not rely only on the calendar. Check the crop. Once most viable seed has germinated, roots are anchored and seedlings are pushing upwards strongly, it is generally time to remove direct pressure and move to the next stage.
Related guide: See When & How to Weight Microgreens: Stacking and Blackout Guide for crop-specific guidance on weighting, stacking, blackout and when to move seedlings into light.
How Much Light Do Microgreens Need?
After germination, microgreens need enough light to develop normal colour and compact growth.
They can be grown using either natural daylight or suitable artificial grow lights.
Natural Light
A bright position can work well where temperatures remain suitable.
Signs of insufficient light include:
- Long, weak stems
- Seedlings leaning strongly towards a window
- Pale foliage
- Loose or stretched growth
Direct Sunlight
Microgreens do not necessarily need intense direct sunlight. Bright indirect light or gentle morning sun can be easier to manage than strong afternoon sun.
This is particularly important in Australian summer conditions, where shallow trays can heat rapidly.
Grow Lights
Artificial lights are useful for indoor shelves, winter production, rooms with limited natural light and growers producing several trays in succession.
The goal is even illumination across the tray without excessive heat or large differences in light intensity.
Related guide: See our Microgreen Lighting Guide: Sunlight vs Grow Lights in Australia for lighting duration, intensity, positioning and diagnosing pale or leggy growth.
How Should You Water Microgreens?
Watering changes as the crop develops.
Before Sowing
Moisten the growing medium evenly before adding seed.
During Germination
If the surface begins to dry, use gentle watering or a fine mist without flooding the tray.
After Root Establishment
Once the roots develop through the medium, bottom watering is generally easier and reduces unnecessary moisture on the leaves and stems.
There is no useful universal instruction such as “water once per day”.
Water use changes with crop type, plant age, tray size, growing medium, temperature, humidity, airflow and light intensity.
A mature tray of pea shoots may use considerably more water than a newly germinated tray of broccoli.
Related guide: See How to Water Microgreens in Australia: Misting vs Bottom Watering for watering during germination, bottom watering and adjusting moisture for Australian growing conditions.
What Are the Best Trays for Growing Microgreens?
Microgreens generally do not need deep containers because the crop is harvested while young.
A practical setup uses two trays:
- A perforated growing tray with drainage holes.
- A solid lower tray for catching drainage and bottom watering.
Why Drainage Matters
Drainage allows excess water to leave the root zone and prevents the growing medium from remaining unnecessarily waterlogged.
How Deep Should a Microgreen Tray Be?
Around 2–4 cm of growing medium is sufficient for many small-seeded crops. Peas, sunflower and other vigorous large-seeded crops can benefit from a slightly deeper root zone.
Small Trays vs 10 × 20 Trays
Small trays are useful for beginners, testing varieties and households wanting modest harvests.
Standard 10 × 20 inch style trays are widely used for larger-scale growing because seeding rates, lighting and production can be standardised more easily.
Related guide: See Best Trays for Growing Microgreens in Australia for 30 × 35 cm, 1010 and 1020 trays, drainage, tray depth and bottom-watering setups.
What Is the Best Growing Medium for Microgreens?
Several growing media can work successfully. The best choice depends on the crop, watering method and growing environment.
| Medium | Useful Features | Considerations |
|---|---|---|
| Seed-raising mix | Good physical support and familiar to home gardeners | Choose a fine, well-draining product suitable for edible crops |
| Coco coir | Uniform and useful moisture retention | Avoid keeping it excessively wet |
| Hemp growing mat | Compact and clean alternative for suitable crops | Water management differs from loose media |
| Reusable silicone mesh | Reusable support surface for suitable soilless systems | Holds little water itself and requires careful irrigation and cleaning |
A suitable medium should hold enough moisture for germination while allowing drainage and air around the root zone.
Related guide: Compare propagation mixes, coco coir, fibre mats and reusable growing systems in our Best Growing Medium for Microgreens in Australia guide.
Temperature, Humidity and Airflow
Microgreen varieties do not all prefer exactly the same temperature. Brassicas such as broccoli and radish behave differently from warmth-loving herbs such as basil.
Temperature
Excessive heat increases water demand and can rapidly dry shallow trays. Cool conditions can slow germination and lengthen the crop cycle.
Humidity
High humidity slows evaporation and can leave dense microgreen canopies wet for longer.
Airflow
Good airflow helps prevent pockets of stagnant humid air around the crop. The goal is ventilation, not continually blasting young seedlings with a strong fan.
Subtropical growing tip: In humid areas such as Brisbane and coastal Queensland, avoid combining very dense sowing, excessive surface watering and poor ventilation.
Related guide: See Growing Microgreens in Hot, Cold & Humid Australian Conditions for seasonal temperature, humidity and airflow management.
Microgreen Growing and Harvest Times
The following ranges are general starting points. Actual growing time varies with seed batch, temperature, light and growing method.
| Crop | Pre-soak | Typical Harvest | Difficulty |
|---|---|---|---|
| Broccoli | Normally no | Approx. 8–14 days | Easy |
| Radish | Normally no | Approx. 7–12 days | Easy |
| Mustard | Normally no | Approx. 8–14 days | Easy |
| Pea shoots | Usually | Approx. 10–14 days | Easy–moderate |
| Sunflower | Usually | Approx. 9–14 days | Moderate |
| Kale | Normally no | Approx. 8–14 days | Easy |
| Basil | Normally no | Often 14–25+ days | Moderate |
Related guide: See When to Harvest Microgreens: Harvesting, Washing & Storage Guide for harvest stage, cutting, washing, refrigeration and storage.
Growing Microgreens in Australian Conditions
Microgreens can be grown year-round, particularly indoors, but Australian weather can substantially affect watering, growth speed and crop management.
Hot Weather
- Shallow trays can dry rapidly.
- Mature crops may use significantly more water.
- Direct sunlight through glass can overheat seedlings.
- Heat combined with excessive moisture can increase disease pressure.
Humid Weather
- Reduce unnecessary wetting of mature foliage.
- Maintain space between trays.
- Provide adequate ventilation.
- Avoid excessive seeding density.
- Do not leave water sitting indefinitely in lower trays.
Cool Weather
Growth may slow in winter, particularly for warmth-loving varieties. Indoor lighting and a more stable growing environment can help reduce seasonal variation.
For detailed seasonal guidance, see Growing Microgreens in Hot, Cold & Humid Australian Conditions.
Common Microgreen Problems
| Problem | Possible Cause | What to Check |
|---|---|---|
| Poor germination | Temperature, moisture, soaking or poor seed contact | Seed instructions, moisture and germination conditions |
| Leggy seedlings | Insufficient light or too much time in blackout | Lighting and uncovering time |
| Seedlings falling over | Overwatering, drying, weak roots or damping-off | Watering, roots, airflow and light |
| Yellow after blackout | Lack of light while covered | Usually normal immediately after uncovering |
| Medium remains wet | Overwatering, poor drainage or high humidity | Drainage, lower tray, airflow and water volume |
| White fuzz around roots | Root hairs or fungal growth | Root hairs grow uniformly from roots; mould tends to spread irregularly |
Having problems? Use our Microgreen Troubleshooting Guide to diagnose mould, root hairs, poor germination, rotting seed, yellowing, wilting and uneven growth.
How to Harvest Microgreens
- Use clean scissors or a sharp harvesting knife.
- Where practical, harvest when the foliage is relatively dry.
- Cut stems just above the growing medium.
- Avoid cutting soil, coir or roots into the crop.
- Transfer the microgreens to a clean container.
- Refrigerate promptly after harvest.
If microgreens are washed before refrigeration, drain and dry them thoroughly before storage.
Related guide: See When to Harvest Microgreens: Harvesting, Washing & Storage Guide for more information about harvest stage, cutting, washing, drying, refrigeration and storage.
Microgreen Food Safety and Hygiene
Microgreens are commonly eaten raw, so clean growing and harvesting practices matter.
- Start with clean trays and tools.
- Use clean drinking-quality water.
- Check seed-treatment information before growing edible microgreens.
- Use clean growing media suitable for edible plants.
- Maintain good drainage and airflow.
- Avoid prolonged waterlogging.
- Use clean harvesting equipment.
- Refrigerate harvested microgreens promptly.
- Discard trays showing obvious mould, slime, decay or unpleasant odours.
Complete Microgreen Growing Guides
This page covers the complete growing process. Use the detailed guides below when you need specific information about each stage of growing microgreens.
Microgreen Seeding Density Chart
Starting seed rates for different crops and common Australian microgreen tray sizes.
Misting, bottom watering and adjusting moisture according to crop and growing conditions.
Stacking, weighted germination, blackout and knowing when to move seedlings into light.
Sunlight, grow lights, lighting duration and diagnosing pale or leggy growth.
Best Trays for Growing Microgreens
Australian tray sizes, 1010 and 1020 trays, drainage, depth and bottom watering.
Best Growing Medium for Microgreens
Compare propagation mix, coco coir, fibre mats and reusable growing systems.
Temperature, Humidity & Airflow
Growing microgreens through hot, cold and humid Australian conditions.
Microgreen Troubleshooting Guide
Diagnose mould, poor germination, rotting seed, yellowing, wilting and uneven growth.
When to harvest, how to cut microgreens, washing, refrigeration and storage.
Frequently Asked Questions About Growing Microgreens
How long do microgreens take to grow?
Many fast-growing varieties are ready in approximately 7–14 days. Slower herbs and speciality crops may require several weeks.
What are the easiest microgreens to grow?
Broccoli, radish and mustard are useful beginner crops because they germinate quickly and normally do not require pre-soaking. Pea shoots are also relatively straightforward once you are comfortable soaking larger seed.
Can microgreens grow indoors?
Yes. Microgreens can be grown indoors throughout the year where they receive suitable light after germination and have adequate temperature and airflow.
Can you grow microgreens on a windowsill?
Yes. A bright windowsill can work well for a small number of trays. Watch for seedlings leaning towards the window and excessive heat from strong direct sunlight through glass.
Do microgreens need grow lights?
Not necessarily. Suitable natural light may be sufficient. Grow lights are useful where natural light is weak, inconsistent or difficult to control.
Do microgreens need soil?
No. Microgreens can be grown in suitable seed-raising mixes, coco coir, soil-based media, fibre growing mats and some reusable soilless systems.
How deep should a microgreen tray be?
Around 2–4 cm of growing medium is a useful starting point for many crops. Peas and sunflower can benefit from a somewhat deeper root zone.
Do microgreen trays need drainage holes?
Drainage holes are highly useful because they allow excess water to leave the root zone and enable bottom watering when the growing tray is placed inside a solid lower tray.
Should microgreens be misted or bottom watered?
Gentle surface watering can be useful during sowing and early germination. Once roots are established, bottom watering is generally preferable.
Do microgreen seeds need soaking?
It depends on the crop. Small seeds such as broccoli, radish and mustard are normally sown without soaking. Larger seeds such as peas and sunflower usually benefit from pre-soaking.
Do all microgreens need blackout?
No. Covered germination, blackout time and weighting vary between crops.
Why are my microgreens yellow after blackout?
Seedlings grown without light are often pale when first uncovered. This is usually normal and they should begin developing their characteristic colour after exposure to suitable light.
Why are my microgreens leggy?
Long, weak seedlings commonly indicate insufficient light or that the crop remained covered for too long.
What is the white fuzz on microgreen roots?
Fine white hairs growing evenly from individual roots are often normal root hairs. Mould is more likely to spread irregularly across the growing medium or between plants.
When should microgreens be harvested?
Many microgreens are harvested once their cotyledons are fully developed or as the first true leaves begin to appear. Pea shoots and wheatgrass are generally judged by shoot development rather than the same cotyledon stage used for crops such as broccoli and radish.
Should microgreens be washed before eating?
Treat microgreens as fresh produce and wash them appropriately before consumption. If storing freshly harvested microgreens, unnecessary surface moisture can reduce storage quality, so many home growers wash them immediately before use rather than storing them wet.
Can microgreens regrow after cutting?
Most microgreens are best treated as a single-harvest crop. Some crops such as peas may produce limited regrowth, but a second harvest is usually less uniform.
Choose Microgreen Seeds for Your Next Tray
Seedmart Australia supplies microgreen seed for home growers, chefs, market gardeners and commercial production, with packet and bulk quantities available across many varieties.