Plant Profile
KomatsunaBrassica rapa var. perviridis
Komatsuna, often called Japanese mustard spinach, is a gem for year-round gardening. It grows extremely fast and can be harvested as tender baby leaf after just a few weeks. Its cold tolerance is particularly valuable, allowing for harvests well into the winter months.
Quick profile
Key data
Suitable growing locations:
Good neighbors
TomatoesOnions
Avoid
Other brassicasCabbage
Indoor & direct sowing
Komatsuna: Sowing and germination
Pre-culture possible for early harvests or in late summer.
Direct sow every 2-3 weeks for continuous harvest; tolerates light frost.
Planting & site
Komatsuna: Planting and spacing
Transplant seedlings when they have approximately 4 leaves.
Site & practical notes
Topic: bolting_prevention, Notes: In midsummer, Komatsuna bolts extremely fast. During this time, only grow in partial shade and water abundantly.
Temperature & frost
Komatsuna: Temperature and site
Water & nutrients
Komatsuna: Water, nutrients and care
Container & growth
Komatsuna: Container, support and growth
Year plan
Komatsuna Calendar
When everything else in the garden is dormant, Komatsuna brings fresh greens to the table.
Recurring tasks
Relevant now
June
- No additional single task
Next up
July
- No additional single task
Monthly tasks
Single tasks from monthly data; repeated seasonal windows are shown in the overview above.
January
Quiet month
February
No additional single task
March
Direct sowing
- Pre-cultureSow in trays for early cultivation.
April
No additional single task
May
No additional single task
June
No additional single task
August
No additional single task
September
No additional single task
October
No additional single task
November
No additional single task
December
Quiet month
Flowering & pollination
Komatsuna Flowering & pollination
Flowering period
April to June (if overwintered) or during heat stress
Flower color
Yellow
Self-fertility
partially self-fertile
Pollinator needed
yes
Overview
Cross-pollination by insects, primarily bees and hoverflies.
Notes
Like most brassicas, Komatsuna benefits significantly from insect pollination for seed set.
Pruning & care
Komatsuna Pruning & care
Pruning type
cut_and_come_again
Pruning timing
Ongoing harvest and vitality Regular picking encourages the formation of new leaves.
Remove
Preserve
Avoid
Tools and hygiene
Use clean knives or shears to avoid rot at the cutting sites.
Companion guide
Komatsuna Companion guide
Good neighbors
TomatoesOnions
Avoid
Other brassicasCabbage
Use & storage
Komatsuna Use & storage
Harvest as baby leaf after 3 weeks or full grown after 6-8 weeks.
Storage
Short-term storage (fresh)
Storage life
2 to 5 days in the refrigerator.
Flavor
Mild, slightly sweet with a subtle mustard note; less pungent than other mustard greens.
Harvest
Harvest as baby leaf after 3 weeks or full grown after 6-8 weeks.
Processing
After harvest
Cool leaves immediately or wrap in a damp cloth to prevent wilting.
Edibility & safety
Komatsuna Edibility & safety
For people
In brief: which parts are edible, which parts remain risky, and whether raw consumption makes sense.
Safety notes
Non-toxic. Like all brassicas, it contains glucosinolates, which are health-promoting in normal quantities.
Animal safety
For many animals, this plant is generally low-risk: 14 animal types are rated suitable or mostly suitable. Quantity, plant part, and individual tolerance still matter.
Each row shows which parts are more suitable and which parts are critical.
Companion animals
DogLeaves, Stems
Roots, Old, woody stems
Leaves, Stems
Roots, Old, woody stems
Overconsumption
Gas, Gastrointestinal upset
observe
Komatsuna is edible and nutritious for dogs. Like all brassicas, it contains glucosinolates, which are health-promoting in normal quantities. Overconsumption may cause gas or gastrointestinal upset. Young leaves are particularly tender and flavorful. Roots and old, woody stems are not recommended but are not toxic.
Open animal page
CatLeaves, Stems
Roots, Old, woody stems
Leaves, Stems
Roots, Old, woody stems
Overconsumption
Gastrointestinal upset with overconsumption
observe
Komatsuna is edible and nutritious for cats. Like all brassicas, it contains glucosinolates, which are health-promoting in normal quantities. Young leaves are particularly tender and flavorful. No known toxic effects in cats with usual feeding. Roots and old, woody stems are not recommended.
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RabbitLeaves, Stems
Roots, Old, woody stems
Leaves, Stems
Roots, Old, woody stems
Overconsumption
Gastrointestinal upset with overconsumption
observe
Komatsuna is safe for rabbits in moderation. The leaves and young stems are nutritious and palatable. Roots and old, woody stems should be avoided due to potential irritants and poor digestibility. Glucosinolates are beneficial in normal amounts but may cause gastrointestinal upset with overconsumption. Introduce slowly and in small amounts.
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Guinea pigLeaves, Stems
Roots, Old, woody stems
Leaves, Stems
Roots, Old, woody stems
Overconsumption
Gastrointestinal upset with overconsumption
observe
Komatsuna is safe for guinea pigs in moderation. The leaves and young stems are nutritious and palatable. Roots and old, woody stems should be avoided due to potential irritants and poor digestibility. Glucosinolates are beneficial in normal amounts but may cause gastrointestinal upset with overconsumption. Introduce slowly and in small amounts.
Open animal page
HamsterLeaves, Stems
Roots, Old, woody stems
Leaves, Stems
Roots, Old, woody stems
Overconsumption
Gastrointestinal upset with overconsumption
observe
No direct species-specific source was found for hamsters. This is a cautious inference from the rabbits profile and the known plant-part risks.
Open animal page
BudgieLeaves, Stems
No risk parts listed
Leaves, Stems
No risk parts listed
Overconsumption
Gastrointestinal upset if overfed
observe
Komatsuna is suitable for budgies in small amounts as an occasional treat. Like all brassicas, it contains glucosinolates, which are safe in normal amounts but may cause gastrointestinal upset if overfed. Young leaves are particularly tender and well-tolerated. Roots and old, woody stems should be avoided as they are difficult to digest and not commonly consumed. No serious toxicities documented for birds. If signs…
Open animal pageFarm animals
HorseLeaves, Stems
Roots, Old, woody stems
Leaves, Stems
Roots, Old, woody stems
Overconsumption
Bloating with overconsumption
usually no action needed
Komatsuna is safe and nutritious for horses. All commonly used parts (leaves, stems, flower buds, young flower stalks) can be fed. Like all brassicas, it contains glucosinolates, which are beneficial in normal amounts. Very large quantities may cause gas or bloating. Roots and old, woody stems are not recommended but are not toxic.
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ChickenLeaves, Stems
Roots
Leaves, Stems
Roots
Overconsumption
Gastrointestinal upset with overfeeding
observe
Komatsuna leaves and young stems are suitable for chickens as an occasional feed. Like all brassicas, it contains glucosinolates, which are beneficial in normal amounts but may cause gastrointestinal upset with overconsumption. Old, woody stems and roots should be avoided. No specific poisoning cases found in chickens, but a conservative classification is made based on plant family knowledge and feed value analysis.
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DuckLeaves, Stems
Roots, Old, woody stems
Leaves, Stems
Roots, Old, woody stems
Overconsumption
Gastrointestinal upset with overconsumption
usually no action needed
Komatsuna is safe and nutritious for ducks. All aerial parts are edible and well tolerated. Like all brassicas, it contains glucosinolates, which are health-promoting in normal quantities. Only very large amounts may cause digestive discomfort. Roots and old, woody stems are not recommended but are not toxic.
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GooseLeaves, Stems
Roots, Old, woody stems
Leaves, Stems
Roots, Old, woody stems
Overconsumption
Bloating with overconsumption
usually no action needed
Komatsuna is safe and nutritious for geese. All aerial parts can be fed. Like all brassicas, it contains glucosinolates, which are beneficial in normal amounts. Overconsumption may cause bloating. Roots and old, woody stems should be avoided as they are difficult to digest but not toxic.
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SheepLeaves, Stems
Roots, Old, woody stems
Leaves, Stems
Roots, Old, woody stems
Overconsumption
Bloating with overconsumption
usually no action needed
Komatsuna is safe and nutritious for sheep. All aerial parts can be fed. Like all brassicas, it contains glucosinolates, which are beneficial in normal amounts. Overconsumption may cause bloating. Roots and old, woody stems should be avoided as they are difficult to digest but not toxic.
Open animal page
GoatLeaves, Stems
Roots, Old, woody stems
Leaves, Stems
Roots, Old, woody stems
Overconsumption
Bloating with overconsumption
usually no action needed
Komatsuna is safe and nutritious for goats. All aerial parts can be fed. As with all brassicas, introduce gradually to avoid digestive upset. Glucosinolates are beneficial in normal amounts, but very large quantities could affect thyroid function. Roots and old woody stems are not recommended but are not toxic.
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CattleLeaves, Stems
Roots, Old, woody stems
Leaves, Stems
Roots, Old, woody stems
Excessive consumption of old, woody stems, Large quantities at once
Gastrointestinal upset with overfeeding
observe
Komatsuna leaves and young stems are suitable for cattle as occasional green fodder. Like all brassicas, it contains glucosinolates, which are beneficial in normal amounts but may cause gastrointestinal upset with overconsumption. Old, woody stems should be avoided. No specific poisoning cases found in cattle, but a conservative classification is made based on plant family knowledge and feed value analysis.
Open animal page
PigLeaves, Stems
Roots, Old, woody stems
Leaves, Stems
Roots, Old, woody stems
Overconsumption
Gastrointestinal upset with overconsumption
observe
Komatsuna is safe for pigs in moderation. The leaves and young stems are nutritious and palatable. Roots and old, woody stems should be avoided due to potential irritants and poor digestibility. Glucosinolates are beneficial in normal amounts but may cause gastrointestinal upset with overconsumption. Introduce slowly and in small amounts.
Open animal pageThese guidelines are for general information only and do not replace veterinary diagnosis. If critical plant parts were ingested or the animal shows unusual behaviour or symptoms, seek veterinary advice.
Max risk
unknown
Highest status
moderation only
Urgency
observe
Saving seed
Komatsuna Saving seed
Seed type
Pods (siliques)
Seed viability
3 - 5 years
Practical tips
Komatsuna Practical tips
Common beginner mistakes
Sowing too densely without later thinning leads to stunted growth.
Success pattern
Spring sowing under fleece guarantees tender leaves before the first pest pressure.
High-impact tips
Use Komatsuna as a follow-up crop in harvested tomato beds in August.
Grower observations
Komatsuna recovers remarkably well in the bed after freezing as soon as it thaws.
Plant Profile
Additional plant images
Health
Pests, Diseases
Plant health
Diagnosis help
Komatsuna Diagnosis help
Pest groups
Disease groups
Prevention
Diagnosis
For wilting leaves, check soil moisture first, then inspect roots for swelling.
Cultural prevention
Monitoring
Weekly inspection of leaf undersides
First response
Diagnostic rules
Many small holes in young leaves
Possible causes: Flea beetles
- Look for jumping beetles
- Check soil moisture
FAQ
Is Komatsuna winter hardy?
Yes, Komatsuna tolerates frosts down to approx. -10°C without issues and can be harvested in winter.
Is Komatsuna safe for Dog?
Komatsuna is classified as moderation only for Dog. Risk: unknown. Urgency: observe. Komatsuna is edible and nutritious for dogs. Like all brassicas, it contains glucosinolates, which are health-promoting in normal quantities. Overconsumption may cause gas or gastrointestinal upset. Young leaves are particularly tender and flavorful. Roots and old, woody stems are not recommended but are not toxic.
Is Komatsuna safe for Cat?
Komatsuna is classified as moderation only for Cat. Risk: unknown. Urgency: observe. Komatsuna is edible and nutritious for cats. Like all brassicas, it contains glucosinolates, which are health-promoting in normal quantities. Young leaves are particularly tender and flavorful. No known toxic effects in cats with usual feeding. Roots and old, woody stems are not recommended.
Is Komatsuna safe for Rabbit?
Komatsuna is classified as moderation only for Rabbit. Risk: unknown. Urgency: observe. Komatsuna is safe for rabbits in moderation. The leaves and young stems are nutritious and palatable. Roots and old, woody stems should be avoided due to potential irritants and poor digestibility. Glucosinolates are beneficial in normal amounts but may cause gastrointestinal upset with overconsumption. Introduce slowly and in small amounts.
Is Komatsuna safe for Guinea pig?
Komatsuna is classified as moderation only for Guinea pig. Risk: unknown. Urgency: observe. Komatsuna is safe for guinea pigs in moderation. The leaves and young stems are nutritious and palatable. Roots and old, woody stems should be avoided due to potential irritants and poor digestibility. Glucosinolates are beneficial in normal amounts but may cause gastrointestinal upset with overconsumption. Introduce slowly and in small amounts.
Guides
Related guides
Guide
Rabbits in the Garden: Herbs and Vegetables
Learn how to choose suitable herbs and vegetables for rabbits, grow feeding plants, and plan a rabbit-friendly garden.
Guide
Chickens in the Garden: Safe Plants and Zones
Learn how to design a chicken-friendly garden with suitable plants, protected beds, and well-planned activity areas.
Guide
Dogs in the Garden: Windfall Fruit and Risks
Keep your garden dog-safe by managing windfall fruit, seeds, stored crops, and potentially problematic plant parts.
Guide
Horse Pastures and Garden Plants: Safety Checks
Learn how to identify risks near horse pastures, fences, turnout areas, fruit trees, and garden planting zones.
Internal links
Related plants
Sources
Public sources
- Wikidata entity
Wikidata · 2026-05-13
- GBIF species match
GBIF · 2026-05-13
- Deutschsprachige Wikipedia: Komatsuna
Wikipedia · 2026-05-13
- English Wikipedia: Komatsuna
Wikipedia · 2026-05-13