leafy green
EdibleMustard Greens
Brassica juncea
Considered non-toxic to cats and dogs (source: ASPCA (not listed; brassica)).
Some direct sun — an east or west window, or a few hours of direct light.
Keep evenly moist — water when the top inch of soil is dry.
Forgiving and beginner-friendly.
Mustard greens are a fast, spicy leafy crop that grows much like arugula and adds a peppery kick. Harvest young leaves for milder flavor and the plant resprouts for more.
About Mustard Greens
Mustard greens (Brassica juncea) are a fast leafy crop grown for their peppery, slightly fiery leaves. The species traces back to Asia and has a long history in Indian, Chinese, and Southern American cooking. For a small space they're a quick return. Sow thickly in a 4-litre pot, cut as a baby-leaf crop, and the plants resprout for several rounds before they bolt. They grow much like arugula, so anyone who's grown that will find the rhythm familiar.
They take medium light, which makes them practical for a window that isn't blazing, and they grow well under a clip-on light. Flavor and heat both depend on conditions. Pick the leaves young and the bite stays mild; let the plants warm up and the leaves turn hotter and the plants rush to flower. Keeping things cool slows that down. A first cut comes fast, usually within 30 to 45 days of sowing.
What it’s like to grow
Mustard greens are easy and quick, and the main thing to read is heat. Warm conditions make the leaves sharper and send the plants bolting, so harvest young and keep them cool if you want a milder green. Pale, stretched seedlings point to weak light. Flea-beetle pinholes can show up if the pot goes outdoors. They're non-toxic to cats and dogs. Good for someone who likes a spicy salad leaf and wants a crop that's ready in a matter of weeks.
What to expect
First harvest in about 30–45 days. It’s forgiving, so it’s a good one to learn on. No sunny window? It also does fine under a clip-on grow light.
See what you’ll need to get started ↓Companions
Tips
- Pick leaves young for a milder, less fiery bite.
- Keep it cool; heat makes leaves hotter and triggers bolting.
- Sow thickly and cut as a baby-leaf crop for the fastest turnaround.
Common problems
- Sharper, hotter flavor and fast bolting in warm conditions.
- Flea-beetle pinholes if exposed to outdoor air.
Common questions
Is Mustard Greens toxic to cats and dogs?
Mustard Greens is non-toxic to cats and dogs, which makes it a safe pick if you have pets. Source: ASPCA (not listed; brassica).
How much light does Mustard Greens need?
Mustard Greens does best in medium, indirect light: near an east or west window, or a little back from a bright one. Direct midday sun can scorch it.
How often should I water Mustard Greens?
Water Mustard Greens when the top inch of soil feels dry, then let it drain. Aim for evenly moist, not soggy.
What temperature does Mustard Greens need?
Mustard Greens is happiest around 10–24 °C. It tolerates brief dips to about -6 °C, but cold drafts and sudden chills set it back.
How long does Mustard Greens take to grow?
Expect a first harvest about 30–45 days from sowing under good conditions. Fast and peppery; one sowing gives several cut-and-come-again harvests of spicy leaves before bolting.
Can I grow Mustard Greens without a sunny window?
Yes. Mustard Greens does well under an affordable clip-on grow light, so a bright window isn't essential.
How big does Mustard Greens get?
A peppery leafy plant ~0.2–0.3 m tall; sow thickly and cut as a patch.
How do I propagate Mustard Greens?
Sow seeds thickly and shallowly; cut young as a baby-leaf crop for milder flavor.
What pests affect Mustard Greens?
Watch for flea beetles, aphids and cabbage worms. Check new growth and the undersides of leaves often, and treat early with a rinse or insecticidal soap before they spread.
Is Mustard Greens easy to grow?
Yes. Mustard Greens is forgiving and one of the better plants to learn on.
Gear for Mustard Greens
Gear suggestions to get you started — general picks, not paid placements.
Pet-toxicity from the ASPCA. Care details are general guidance, not professional or veterinary advice; only eat plants you can positively identify as the edible plant and part described. Photo: Mouchumi, CC BY-SA 3.0, via Wikimedia Commons (CC-BY-SA). Care info last updated 2026-06-02.