Rocket microgreens, also known as arugula microgreens, are fast-growing greens with a fresh, peppery flavour. Their soft green leaves and distinctive spicy taste make them a popular addition to salads, sandwiches, wraps, pizzas and restaurant garnishes.
If you are learning how to grow Rocket microgreens, they are a relatively straightforward crop to start with. The small seeds do not require soaking, germinate quickly and can usually be harvested in approximately 7–14 days.
Rocket can be grown in shallow trays using soil, coco coir, seed-raising mix or suitable microgreen growing mats. Like other densely sown microgreens, good airflow and careful watering become increasingly important as the crop develops.
This step-by-step guide explains Rocket microgreen seed rate, germination, covered growing, watering, light, temperature, harvesting and common growing problems.
Rocket Microgreens at a Glance
What Are Rocket Microgreens?
Rocket microgreens are the young seedlings of salad rocket, usually referred to botanically as Eruca vesicaria subsp. sativa. The plant is also widely listed under the synonymous name Eruca sativa.
In Australia and the United Kingdom, the plant is normally called rocket. In North America, it is more commonly known as arugula. Both names refer to the same familiar peppery salad green.
Rocket belongs to the Brassicaceae family, making it a relative of broccoli, cabbage, kale, mustard, radish, mizuna and kohlrabi.
As a microgreen, Rocket is harvested much earlier than mature salad rocket. The young stems and cotyledons are cut above the growing medium approximately one to two weeks after sowing.
What Do Rocket Microgreens Taste Like?
Rocket microgreens have a distinctive fresh, peppery and mildly spicy flavour.
The flavour resembles mature rocket but is delivered in a tender young seedling. It is stronger than mild brassica microgreens such as broccoli or cabbage, but generally different from the sharper mustard-like heat of many mustard microgreens.
Rocket is particularly useful when you want a microgreen that contributes noticeable flavour rather than simply colour and texture.
Why Grow Rocket Microgreens?
- Fast-growing microgreen with a typical crop time of approximately 7–14 days.
- Distinctive peppery flavour.
- Small seeds do not require pre-soaking.
- Suitable for shallow microgreen trays.
- Can be grown using soil, coco coir or suitable growing mats.
- Useful in salads, sandwiches, wraps and garnishes.
- Works well as a spicy component in mixed microgreen crops.
- Suitable for indoor production with adequate light and airflow.
- Relatively easy for beginner microgreen growers.
Are Rocket Microgreens Easy to Grow?
Yes. Rocket is a relatively easy microgreen to grow.
It has several characteristics that make it suitable for beginners:
- No seed soaking is required.
- Germination is relatively quick.
- The seed is easy to broadcast over a tray.
- The crop establishes rapidly under suitable conditions.
- Harvest is usually within approximately one to two weeks.
Rocket does have relatively fine seed, however, so even sowing is important. Overcrowded patches can retain moisture and reduce airflow through the crop.
How to Grow Rocket Microgreens in 7 Simple Steps
- Prepare the growing tray. Add approximately 2–4 cm of moist seed-raising mix, soil or coco coir to a shallow tray and level the surface.
- Sow the Rocket seeds. Spread approximately 10–12 g of seed evenly across a standard 10 × 20 inch tray.
- Mist thoroughly. Moisten the seeds and growing surface evenly without creating puddles.
- Cover the tray. Place another tray or suitable cover over the seed during the initial germination period.
- Maintain moisture during germination. Check the tray regularly. The medium should remain moist but not waterlogged.
- Move the seedlings into light. After approximately 2–3 days, or once the seedlings are established and pushing upward, remove the cover and provide suitable light and airflow.
- Harvest. Cut the Rocket microgreens just above the growing medium when they reach your preferred size, commonly approximately 7–14 days after sowing.
What You Need to Grow Rocket Microgreens
- Untreated Rocket microgreen seeds
- Shallow growing tray with drainage holes
- Solid lower tray for bottom watering
- Second tray or cover for germination
- Seed-raising mix, fine potting mix, coco coir or suitable growing mat
- Spray mister
- Clean water
- Natural light or suitable LED grow light
- Clean scissors or harvesting knife
Do Rocket Microgreen Seeds Need to Be Soaked?
No. Rocket microgreen seeds do not need to be pre-soaked.
Sow the dry seed directly onto a pre-moistened growing medium.
Rocket seeds are relatively small and absorb sufficient moisture from the damp growing surface during germination.
Pre-soaking fine seeds can make them more difficult to distribute evenly and is unnecessary for this crop.
How Much Rocket Seed Should You Use?
For a standard 10 × 20 inch microgreen tray, approximately 10–12 grams of Rocket seed provides a useful starting range.
For a 10 × 10 inch tray, approximately 5–6 grams provides a proportional starting point.
Seed density is not an absolute measurement. The best rate can vary with:
- Tray dimensions
- Seed size
- Germination percentage
- Growing medium
- Humidity
- Temperature
- Airflow
- Preferred harvest stage
Avoid assuming that more seed automatically produces a better crop. Excessive density can increase competition between seedlings and create a damp canopy with poor airflow.
Best Growing Medium for Rocket Microgreens
Rocket can be grown using several common microgreen growing media.
Seed-Raising Mix
A fine seed-raising mix provides an even growing surface and reliable moisture retention.
Fill the tray with approximately 2–4 cm of medium, moisten it evenly and gently level the surface before sowing.
Fine Potting Mix
A good-quality fine potting mix can also work well.
Remove large pieces of bark or coarse material where necessary so that the small Rocket seeds have consistent contact with the surface.
Coco Coir
Coco coir provides a clean, uniform surface with good moisture retention.
Moisten it before sowing and allow excess water to drain.
Growing Mats
Rocket can also be grown on suitable microgreen growing mats, including hemp-based media.
With mats, maintaining even moisture across the entire growing surface is particularly important because fine seeds can dry quickly if parts of the mat lose contact with water.
Best Temperature for Rocket Microgreens
Rocket is generally comfortable in moderate growing conditions.
A practical indoor range is approximately 18–24°C.
Rocket is a cool-season vegetable when grown to maturity, but microgreens are harvested so quickly that they can be produced across a wider range of conditions.
Very warm conditions combined with high humidity can nevertheless increase crop-management problems, particularly when trays are densely sown or overwatered.
Step 1: Prepare the Growing Tray
Start with clean growing trays.
Add approximately 2–4 cm of moist growing medium and gently level the surface.
The medium should be evenly moist before sowing but should not be saturated or holding standing water.
A flat growing surface is particularly useful for Rocket because the seeds are small and should be distributed evenly across the tray.
Step 2: Sow the Rocket Seeds
Spread approximately 10–12 grams of seed evenly across a 10 × 20 inch tray.
Try to create consistent coverage from edge to edge.
Avoid leaving large bare areas or concentrated clumps of seed.
Once the seed is distributed, gently press it onto the moist surface to improve seed-to-medium contact.
Mist thoroughly using a fine spray.
Rocket seed should remain close to the surface rather than being buried deeply.
Step 3: Cover the Tray for Germination
Place a second tray or suitable blackout cover over the seeded tray.
This helps maintain a stable environment while the seeds absorb moisture and germinate.
Rocket commonly begins germinating quickly under suitable conditions.
During this stage, check the growing medium regularly and mist if necessary.
The aim is to maintain consistent moisture without waterlogging the tray.
Does Rocket Need a Blackout Period?
Rocket benefits from a short covered germination period.
Approximately 2–3 days is commonly sufficient, although the crop itself is a better indicator than the calendar.
Remove the cover once the majority of seedlings are established and pushing upward.
There is usually no need to extend blackout for a long period simply to make the stems taller.
Does Rocket Need Weight During Germination?
Rocket does not require heavy weighting.
A second tray can rest over the seeded crop during germination and provide light, even contact.
Heavy weights such as those sometimes used for pea shoots and sunflower are unnecessary.
How Long Does Rocket Take to Germinate?
Rocket microgreens commonly germinate in approximately 2–4 days under suitable conditions.
Actual timing depends on:
- Temperature
- Seed lot
- Moisture
- Growing medium
- Seed-to-medium contact
If germination is slow, first check whether the growing surface has remained consistently moist and whether the growing area is excessively cold or hot.
Step 4: Move Rocket Microgreens into Light
Once the seedlings are established and pushing against the cover, uncover the tray.
The newly uncovered seedlings may initially appear pale or yellow. This is normal after germination in darkness.
After exposure to suitable light, the cotyledons begin producing chlorophyll and develop their normal green colour.
How Much Light Do Rocket Microgreens Need?
Rocket microgreens require good light after germination to produce compact, green growth.
They can be grown using:
- Bright indirect natural light
- A well-lit windowsill
- LED grow lights
- Protected greenhouse conditions
Indoor growers commonly use approximately 12–16 hours of artificial light per day, although the appropriate intensity and duration depend on the lighting system.
Rocket has also been used in controlled-environment research examining how different lighting regimes affect plant growth and composition. This reinforces an important practical point for home growers: light conditions can influence the way Rocket develops.
For an example of research involving rocket grown under controlled LED lighting, see this peer-reviewed study on Eruca vesicaria and controlled-environment lighting.
Step 5: Water Rocket Microgreens Carefully
During early germination, mist from above as required to maintain consistent surface moisture.
Once the root system has established, bottom watering is generally preferable.
Add clean water to the solid lower tray and allow moisture to move upward through the drainage holes.
Bottom watering helps keep the foliage drier than repeated overhead watering.
Do not leave the growing tray permanently sitting in deep water.
Avoid These Watering Mistakes
- Allowing the growing medium to dry completely
- Keeping the tray constantly saturated
- Leaving standing water beneath the crop
- Frequently soaking the foliage after the canopy develops
- Watering by a fixed schedule without checking the tray first
Water requirements change with temperature, airflow, humidity, tray size and stage of growth.
Step 6: Grow Rocket Until the Cotyledons Are Open
After exposure to light, Rocket grows rapidly.
The seedlings develop slender stems and a pair of green cotyledons.
For a typical microgreen crop, Rocket can be harvested at the cotyledon stage or around the early development of the first true leaves.
Allowing the crop to grow much longer moves it towards baby-leaf production rather than conventional microgreens.
Step 7: When to Harvest Rocket Microgreens
Rocket microgreens are commonly ready to harvest approximately 7–14 days after sowing.
Rather than harvesting on a fixed day, assess the crop itself.
Good Harvest Indicators
- Cotyledons are fully opened.
- Leaves have developed healthy green colour.
- Stems are upright and firm.
- The crop has reached approximately 5–8 cm tall.
- The first true leaves may just be beginning to develop.
- The crop has its characteristic fresh Rocket aroma and peppery flavour.
Harvest timing can be adjusted according to your preferred appearance, texture and flavour.
How to Harvest Rocket Microgreens
Use clean, sharp scissors or a harvesting knife.
Cut the stems just above the surface of the growing medium.
Avoid pulling the seedlings from the tray, as this brings roots and growing medium into the harvested crop.
If possible, harvest when the foliage is dry rather than immediately after overhead watering.
Rocket is normally treated as a single-cut microgreen crop. Sow another tray for your next harvest.
How to Store Rocket Microgreens
After harvesting, keep Rocket microgreens refrigerated in a clean container.
They store best when the foliage is reasonably dry.
If washing before storage, drain and dry the crop thoroughly before placing it in the refrigerator.
A small amount of absorbent paper inside the container can help manage excess condensation.
Use the microgreens while they remain fresh, crisp and free from signs of deterioration.
How to Use Rocket Microgreens
Rocket microgreens are particularly useful when a dish needs a fresh peppery element.
Salads
Add Rocket microgreens to green salads or combine them with milder microgreens to increase flavour.
Sandwiches and Wraps
Use freshly harvested Rocket in sandwiches, burgers and wraps in place of, or alongside, mature salad rocket.
Pizza
Add Rocket microgreens after cooking so the tender leaves remain fresh rather than wilting under prolonged heat.
Egg Dishes
Rocket works well with poached eggs, scrambled eggs, omelettes and savoury breakfast dishes.
Pasta
Add the microgreens shortly before serving for a fresh peppery finish.
Garnishes
The combination of green colour, tender texture and noticeable flavour makes Rocket useful for restaurant-style garnishes.
Rocket Microgreens and Mature Rocket
Rocket microgreens and mature salad rocket come from the same plant but are harvested at very different stages.
Rocket vs Broccoli Microgreens
Rocket and broccoli are both Brassicaceae microgreens and share similar basic growing methods, but their flavours are noticeably different.
Rocket vs Radish Microgreens
Rocket and radish both provide peppery flavour, but they produce distinctly different crops.
Rocket vs Mustard Microgreens
Rocket and mustard both suit growers who want a stronger-flavoured microgreen, but they do not taste the same.
Growing Rocket Microgreens in Warm and Humid Conditions
Rocket microgreens can be grown throughout much of the year indoors, but growers in Brisbane and other warm, humid parts of Australia need to pay particular attention to moisture and airflow during warmer months.
High humidity slows evaporation from both the growing medium and the leaves. If dense trays are also heavily watered, moisture can remain trapped around the stems and growing surface.
During warm and humid conditions:
- Avoid excessively dense sowing.
- Use trays with reliable drainage.
- Provide good airflow around the crop.
- Bottom water after the roots are established.
- Avoid leaving standing water in the lower tray.
- Do not keep established seedlings covered unnecessarily.
- Keep trays away from intense afternoon heat through windows.
- Check moisture before watering rather than automatically watering on a schedule.
Rocket is generally forgiving, but good ventilation becomes increasingly important as temperature and humidity rise.
Common Problems When Growing Rocket Microgreens
Mould on the Growing Surface
Mould is more likely when seed is overcrowded, trays are kept too wet or airflow is inadequate.
Use clean equipment, sow at an appropriate density and avoid persistent saturation.
Discard visibly mouldy or spoiled crops rather than consuming them.
Root Hairs Mistaken for Mould
Rocket seedlings can develop fine white root hairs around their roots.
These are a normal part of seedling development and are often most noticeable when the growing surface is relatively dry.
Root hairs generally occur uniformly around healthy roots and often become much less visible after misting.
Mould tends to spread irregularly across seed hulls, stems or the growing medium rather than remaining neatly associated with individual roots.
Uneven Germination
Uneven germination can result from patchy watering, irregular seed distribution or inconsistent seed-to-medium contact.
Level the medium before sowing and distribute the fine seed carefully across the entire tray.
Seedlings Are Pale After Blackout
Pale or yellow seedlings immediately after uncovering are usually normal.
The crop has germinated without light and will generally become greener after exposure to suitable growing light.
Rocket Microgreens Are Tall and Weak
Long, weak stems can result from insufficient light or keeping the crop covered for too long after establishment.
Move established seedlings into suitable light once they are pushing upward.
Seedlings Are Falling Over
Falling seedlings may indicate insufficient light, excessive watering, poor root establishment or disease.
Check the roots and growing medium rather than automatically adding more water.
Rocket Microgreens Are Wilting
Wilting commonly indicates that the crop requires water, particularly once the canopy becomes established.
Check the growing medium first. If it is dry, bottom water and allow the medium to absorb moisture.
If the medium is already saturated, wilting may have another cause and additional watering can make the problem worse.
Seeds Germinate in Clumps
Rocket seed is fine and can easily collect in patches during sowing.
Take additional time to distribute it evenly and use a gentle mist rather than a strong stream of water that moves seed around the tray.
Frequently Asked Questions
How long do Rocket microgreens take to grow?
Rocket microgreens are commonly ready to harvest approximately 7–14 days after sowing. Temperature, light, moisture and preferred harvest stage can all affect crop time.
Is Rocket the same as arugula?
Yes. Rocket and arugula are common names for the same salad plant. Rocket is the usual Australian and British name, while arugula is commonly used in North America.
What is the botanical name of Rocket?
Rocket is commonly listed as Eruca vesicaria subsp. sativa. The name Eruca sativa is also widely used in horticulture and seed catalogues.
Do Rocket microgreen seeds need to be soaked?
No. Rocket seed can be sown dry directly onto a moist growing medium.
How much Rocket seed should I use in a 10 × 20 tray?
Approximately 10–12 grams provides a practical starting range for a standard 10 × 20 inch tray.
How much Rocket seed should I use in a 10 × 10 tray?
Approximately 5–6 grams provides a useful starting point.
How long does Rocket take to germinate?
Germination commonly takes approximately 2–4 days under suitable microgreen growing conditions.
How long should Rocket microgreens stay covered?
Approximately 2–3 days is a useful guide. Uncover the crop once most seedlings are established and pushing upward.
Do Rocket microgreens need weight?
No heavy weight is normally required. A second tray can provide light coverage during germination.
Can Rocket microgreens be grown without soil?
Yes. Rocket can be grown using suitable soilless media such as coco coir or purpose-made microgreen growing mats.
Do Rocket microgreens need light?
The seed does not require light during initial covered germination. Once the seedlings are established, provide suitable natural or artificial growing light.
What temperature is best for Rocket microgreens?
A practical indoor growing range is approximately 18–24°C.
Can Rocket microgreens grow on a windowsill?
Yes. A bright windowsill can work well provided the crop receives adequate light without becoming excessively hot.
What do Rocket microgreens taste like?
Rocket microgreens have a fresh, peppery and mildly spicy flavour similar to mature salad rocket.
When should Rocket microgreens be harvested?
Harvest when the cotyledons are open, the crop has developed good green colour and the seedlings have reached the size you prefer. This is commonly approximately 7–14 days after sowing.
Can Rocket microgreens regrow after cutting?
Rocket microgreens are generally treated as a single-cut crop. Sow fresh seed for the next harvest.
Are Rocket microgreens good for beginners?
Yes. Rocket is relatively fast-growing, requires no pre-soaking and uses a straightforward tray-growing method.
Why are my Rocket microgreens mouldy?
Excessive moisture, high sowing density and poor airflow can all contribute to mould problems. Improve ventilation, avoid overwatering and make sure excess water can drain from the tray.
Can I grow Rocket microgreens in Brisbane during summer?
Yes, particularly indoors, but warm and humid conditions require more careful management. Good airflow, moderate watering and avoiding excessive tray density become especially important.
Final Tips for Growing Rocket Microgreens
Rocket is a useful microgreen for growers who want a fast crop with considerably more flavour than mild varieties such as broccoli or cabbage.
For reliable results:
- Use untreated seed suitable for microgreen growing.
- Do not pre-soak the seed.
- Start with approximately 10–12 g per 10 × 20 inch tray.
- Spread the fine seed evenly.
- Keep the growing medium moist but not saturated.
- Cover for approximately 2–3 days or until seedlings are established.
- Move the crop into good light after germination.
- Provide adequate airflow.
- Bottom water once roots are established.
- Harvest approximately 7–14 days after sowing.
With its quick growth, peppery flavour and simple growing method, Rocket is an excellent addition to both home microgreen trays and commercial microgreen production.
Ready to grow your own? Shop untreated Rocket Microgreen Seeds from Seedmart Australia.