Vegetable · Brassicaceae
Bok Choy
Brassica rapa subsp. chinensis
Sow it in cool weather, keep it watered and growing fast, and bok choy fills the bed in barely six weeks.
Full sun
Every 2–4 days
50–77°F · 10–25°C
40–55 days
Overview
Bok choy is part of the cabbage family, but it's grown for its crisp stalks and tender leaves instead of a tight head, which keeps things simple. It comes together quickly too, going from seed to a full plant in 40 to 60 days, so it's perfect for filling a bed early in spring or late in fall. Want a few leaves for dinner? Pick the outer ones, or just cut the whole plant at the 10 to 15 leaf stage.
Cool weather is really the secret with this one. It's happiest between 50°F and 77°F (10°C to 25°C), and a cold snap in its first weeks or the heat and long days of summer will nudge it to bolt and go bitter. Aim your sowings at spring and fall and you'll skip most of that headache.
Once it's up and running, it doesn't ask for much. Give it steady moisture, fertile soil, and full sun, though partial shade works too, and you'll be pulling crisp, mild greens for stir-fries and soups in just a few weeks.
Care
The short version: full sun and cool weather, steady moisture at about an inch of water a week, rich soil worked with compost, and a quick harvest at the 10 to 15 leaf stage before the heat sets it bolting.
Light
Bok choy loves full sun and grows fastest and fullest in it, but it's pretty easygoing. It'll still make usable heads on as little as 2 hours of direct sun a day, just at a slower clip, so don't write off a part-shade bed.
Water
Keep the soil evenly moist with about 1 inch (2.5 cm) of water a week from rain or the hose, and a bit more if your ground is sandy. That steady moisture is what keeps the stalks crisp and holds off bolting, so try not to let the bed bounce between bone dry and soaked.
Soil
Go for fertile, well-drained soil that still hangs onto some moisture, and mix in compost or well-rotted manure. A pH of 6.0 to 7.5 is the sweet spot, and nudging toward 7 helps if clubroot has been an issue.
Temperature
This is a cool-weather crop, happiest between 50°F and 77°F (10°C to 25°C). Cold below 50°F in the early weeks can set off bolting, and summer heat pushes it to flower and turn bitter, so timing really is your friend here.
Humidity
Regular outdoor humidity is just fine, so there's no number to chase. What you do want to watch for are the warm, wet spells that crank up pests and disease, and give plants enough elbow room for air to move through.
Feeding
Mix plenty of compost or well-rotted manure into the bed before planting and that carries most crops just fine. If your soil's on the poor side, a light nitrogen side-dress while it's growing keeps the leaves coming.
Pruning
There's really no pruning to fuss with. Just take the outer leaves as you need them or cut the whole head at the 10 to 15 leaf stage, and snip off any flower stalk the second the plant starts to bolt.
Size & spacing
Plants stand 6 to 12 inches (15 to 30 cm) tall and about as wide. Thin dwarf types to roughly 12 inches apart and full-size ones a touch more, so each plant has room to fill out and stay airy.
When to plant
Bok choy is a cool-season crop that bolts when summer turns hot, so it does its best work in the milder shoulders of the year. Start seed indoors a few weeks before the last spring frost or direct-sow right around it, then sow again in midsummer for a fall harvest that fills out as things cool down.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Sow: 4-5 weeks before the last spring frost for an early crop
- Plant: Set transplants out around the last spring frost once hard freezes have passed; direct-sow in midsummer (July) for a fall crop that matures in cool weather
- Harvest: Harvest 40-60 days after seeding at the 10-15 leaf stage, before hot weather triggers bolting; spring and fall crops
Hardiness
USDA hardiness zones: 2–11
Temperature: down to -46°C
Troubleshooting
Most bok choy trouble shows up as chewed leaves, slime near the base, or a plant that suddenly shoots to seed. The good news? Spot those signs early and you can jump in before the crop is gone. Find what matches below, then act while it still makes a difference.
Plants wilt and yellow even though there's plenty of water
When a plant wilts and yellows but the soil's plenty moist, the problem is down at the roots. Clubroot swells them into useless lumpy clubs, while cabbage maggots tunnel through and chew them apart. Here's the catch: clubroot has no cure once it sets in, so pull and destroy any infected plant and don't toss it on the compost.
Fix:
- Remove and destroy infected plants; do not compost them
- There is no cure for clubroot in an infected plant
A tall flower stalk pops up and the leaves stop coming
If a tall stalk suddenly shoots up and leaf growth stalls, that's bolting, usually after a cold spell tricks young plants into flowering or the heat and long days of late spring kick in. From there, the plant pours its energy into seed instead of leaves. The fix? Cut the head before the buds open and you can still eat it, even if it's a little more bitter than usual.
Fix:
- Harvest the head immediately, before the flowers open; it is still edible though it may be slightly bitter
Tiny round holes scattered all over the leaves
Those little pinprick holes are the calling card of flea beetles, tiny shiny black beetles that hop away when you brush the plant and go hardest after seedlings. Lay down a floating row cover at sowing and you'll keep them off. Keep the water steady so plants grow fast, too, and they'll just outrun the damage.
Fix:
- Cover plantings with floating row cover at seeding
- Keep plants growing fast with steady water so they outgrow damage
Ragged chewed holes with dark green droppings
Ragged holes and crumbs of dark frass usually mean cabbage caterpillars, which covers the imported cabbageworm, the cabbage looper, and diamondback moth larvae. Flip the leaves over and check the undersides where they hide, then pick them off. If it gets bad, a spray of Bacillus thuringiensis while they're still small sorts it out.
Fix:
- Handpick caterpillars
- Apply Bacillus thuringiensis (Bt) while caterpillars are small
Slime trails and holes down at the leaf stalks
Silvery trails and chewed stalk bases? That's slugs and snails, which come out after dark to feed in the damp, crowded base of the plant. Go on a night patrol and pick them off by hand, or scatter some iron phosphate bait around the plants. Clearing away mulch and debris near the stems takes away the cover they hide under by day.
Fix:
- Handpick at night
- Use iron phosphate slug bait around plants
- Reduce mulch and debris immediately around stems
Toxicity
Bok choy is a kitchen vegetable through and through, safe for people and not on the ASPCA's toxic list for cats or dogs. The only thing to keep in mind is how much, since the natural goitrogens in all cabbages can cause gas or mild upset if any animal eats a lot of it raw, a lot of the time. Horses are the one exception worth watching, because extension guides say brassicas just don't suit them.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
No need to panic if a cat sneaks a bite, since bok choy isn't on the ASPCA toxic list. The worst a big plate of raw leaves might do is bring on a little gas or a mild upset stomach, and that's it.
Dogs None
A dog can happily share a bit of cooked or raw bok choy with you. The only thing to watch is gas or loose stools if a dog gulps down a big raw helping all at once.
Horses None
Horses are the exception here, since NC State Extension says to keep brassicas out of their diet because the family doesn't agree with them in any quantity. One stray leaf won't hurt, but don't make it a regular thing.
Rabbits None
Rabbits do fine with small servings of the leafy greens. Just bring it in slowly and keep portions modest, because too much rich brassica at once can leave a bunny gassy.
Livestock None
Cattle, goats, and sheep can graze the leaves without any real worry. Like any brassica, though, a diet of nothing but this can upset rumen digestion, so think of it as part of the mix, not the whole meal.
Birds None
Backyard hens and other birds peck away happily at both the leaves and the bolted flowers. In moderation, it's a wholesome green for them.
People Safe
Bok choy is grown to be eaten and it's totally safe in the kitchen, raw in a salad or cooked into a stir-fry. The only thing worth a second thought is a steady habit of large raw amounts, thanks to the natural goitrogens that run through the whole cabbage family.
No special handling needed; safe to grow in household gardens.
Varieties
Bok choy comes in white-stemmed and green-stemmed forms, plus full-size and baby types. These are the few worth knowing by name.
Shanghai (green-stem) type
The Shanghai type, called Shanghai Qing back in China, has spoon-shaped leaves on pale green stalks instead of white ones, and it's often picked young as baby bok choy.
Dwarf types
If you're short on space, dwarf types are the way to go, since they top out around 6 inches, sit as close as 12 inches apart, and mature in a hurry.
'Joi Choi'
'Joi Choi' is a vigorous white-stemmed hybrid that folks love for how slowly it bolts and how easily it handles both cold and warm spells.
'Mei Qing Choi'
'Mei Qing Choi' is a green-stemmed baby pak choi hybrid that does a great job resisting bolting.
Companions
Bok choy grows best beside onions and aromatic herbs that throw pest-laying moths off the scent, and it shares a cool-season bed comfortably with beets.
Plant near
Onions: Extension companion-planting guides note onions get along well with all cabbage-family crops, and onion interplanting helped reduce cabbage looper and imported cabbageworm damage in brassica trials
Aromatic herbs (dill, sage, thyme, chamomile, rosemary): Cole crops do well planted with aromatic herbs; sage and thyme reduced diamondback moth pressure on brassicas in studies
Beets: Extension companion charts list beets as compatible neighbors for cabbage-family crops in the cool-season bed
How to propagate
Bok choy grows from seed, and honestly it's about as easy as sowing gets, with a fresh row ready to start every couple of weeks.
SeedEasy
Direct-sow or start indoors in early spring, and again in mid-to-late summer (around July) for a fall crop · Seed germinates in about 4-10 days in cool soil; plants reach transplant size in 3-4 weeks and harvest size in 40-60 days
Bok choy grows from seed and nothing else, which keeps it simple. Tuck the seed a quarter to half an inch deep in early spring, or again around July for a fall crop, and it'll sprout in 4 to 10 days in cool soil. Thin to one plant every 6 to 12 inches depending on the variety, and from there it's 3 to 4 weeks to transplant size and 40 to 60 days to a full head. Pop in a fresh row every couple of weeks and you'll never run short.
Myths
Once bok choy starts to bolt, the plant is ruined and you have to throw it out.
Don't toss it just yet, because a bolting plant is still good eating if you catch it in time. Cut the head before the flowers open and it eats much like a young one, just a hair more bitter, and the flower stalks are tasty in their own right.
Bok choy needs full sun all day to make a crop.
Sure, full sun grows the fastest, fullest heads, but it's not a deal-breaker if you can't offer that. As little as 2 hours of direct sun a day still yields usable heads, just at a more relaxed pace.