Vegetable · Brassicaceae
Bok Choy
Brassica rapa subsp. chinensis
Get seeds down while the weather stays cool, keep the moisture coming, and watch bok choy overflow its rows in just six weeks.
Full sun
Every 2–4 days
50–77°F · 10–25°C
40–55 days
Overview
Bok choy belongs to the cabbage family but throws all its effort into crisp stalks and tender leaves instead of a tight head, which makes it a joy to grow. It really moves, racing from seed to a full plant in 40 to 60 days, so it slots right into a bed early in spring or late in fall. Grab the outer leaves whenever a meal calls, or cut the whole plant at the 10 to 15 leaf stage and start fresh.
Cool weather is where this crop comes alive. It powers along between 50°F and 77°F (10°C to 25°C), while a cold snap in its early weeks or the heat and long days of summer will send it bolting and turn it bitter. Aim your sowings at spring and fall and you sidestep nearly all of that.
Once it gets going, it barely asks for a thing. Hand it steady moisture, fertile soil, and full sun, though it still crops in partial shade, and in a matter of weeks you are pulling crisp, mild greens straight into stir-fries and soups.
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 fast harvest at the 10 to 15 leaf stage before heat sets it bolting.
Light
Bok choy charges ahead in full sun, where it grows fastest and fullest, but it rolls with less. It still cranks out usable heads on as little as 2 hours of direct sun a day, just at a slower clip, which makes it a smart pick for 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 pour on more in sandy ground. That steady moisture keeps the stalks crisp and holds bolting at bay, so never let the bed lurch from bone dry to soaked.
Soil
Plant it in fertile, well-drained soil that still grips some moisture, turned over with compost or well-rotted manure. A pH of 6.0 to 7.5 hits the mark, and nudging toward 7 gives you an edge where clubroot is a known problem.
Temperature
This cool-weather crop runs best between 50°F and 77°F (10°C to 25°C). Cold below 50°F in the early weeks can kick off bolting, and summer heat shoves it to flower and turn bitter, so smart timing keeps it cruising.
Humidity
Skip the humidity worry, since ordinary outdoor air does the job. Just stay sharp for warm, wet spells that crank up pest and disease pressure, and give plants room so the air keeps moving.
Feeding
Dig plenty of compost or well-rotted manure into the bed before planting and that fuels most crops on its own. On poor ground, a light nitrogen side-dress during growth keeps fresh leaves rolling in.
Pruning
There is no real pruning to bother with. Snatch the outer leaves as you need them or cut the whole head at the 10 to 15 leaf stage, and snap off any flower stalk the second the plant starts to bolt.
Size & spacing
Plants shoot up 6 to 12 inches (15 to 30 cm) tall and about as wide. Thin dwarf types to roughly 12 inches apart and full-size plants a touch more, giving each one room to bulk up and stay airy.
When to plant
Bok choy is a cool-season crop that bolts the moment summer heat hits, so it thrives in the cooler shoulders of the year. Fire up seed indoors a few weeks before the last spring frost or direct-sow around it, then sow again in midsummer for a fall harvest that powers up as the weather cools.
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 waves a clear flag, whether that is chewed leaves, slime at the base, or a plant that suddenly bolts to seed. Spot those signals fast and you can jump in before a crop is lost. Match what you see below, then act while it still turns things around.
Plants sag and go yellow no matter how much you water
When a plant wilts and yellows even though the soil is moist, the answer is down at the roots. Clubroot swells them into useless clubs, while cabbage maggots tunnel through and chew them apart. There is no saving a clubroot-struck plant, so pull it, destroy it, and keep it far from 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 shoots up and leaf growth stalls
A tall stalk rocketing up while the leaves quit is bolting, usually sparked by a cold spell that tricks young plants into flowering or the heat and long days of late spring. From there the plant throws everything into seed instead of leaves. Move fast and cut the head before the buds open, and you can still eat it, just expect a touch more bitterness.
Fix:
- Harvest the head immediately, before the flowers open; it is still edible though it may be slightly bitter
Tiny round shothole holes peppering the leaves
Those little pinprick holes are pure flea beetle work, tiny shiny black beetles that ping away when you brush the plant and hammer seedlings hardest. Throw a floating row cover over the bed at sowing and you shut them out. Keep the water steady so plants grow fast, and they barrel right past the damage.
Fix:
- Cover plantings with floating row cover at seeding
- Keep plants growing fast with steady water so they outgrow damage
Big ragged bites in leaves plus dark green droppings
Ragged holes and crumbs of dark frass scream cabbage caterpillars, the crew that includes the imported cabbageworm, the cabbage looper, and diamondback moth larvae. Flip the leaves and hunt the undersides where they hide, then pick them off. If they get ahead of you, hit them with Bacillus thuringiensis while the caterpillars are still small.
Fix:
- Handpick caterpillars
- Apply Bacillus thuringiensis (Bt) while caterpillars are small
Slimy trails plus chewed holes down at the stalk bottoms
Silvery trails and chewed stalk bases blow the cover of slugs and snails, which sneak out after dark to feed in the damp, crowded base of the plant. Go on a night patrol and pick them off, or scatter iron phosphate bait around the plants. Clear out mulch and debris near the stems and you strip away their daytime hideout.
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 clear of the ASPCA list of plants toxic to cats and dogs, so grow it with gusto. The one thing to keep tabs on is quantity, since the natural goitrogens common to all cabbages can cause gas or mild upset if any animal eats large raw amounts often. Horses are the exception to watch, as extension guides flag brassicas as a poor fit for their diet.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
A cat that grabs a nibble has nothing to fear, since bok choy stays off the ASPCA toxic list. The worst a big plate of raw leaves might stir up is some gas or a mild upset stomach, and that is the end of it.
Dogs None
A dog can dive into a little cooked or raw bok choy without any worry. The only catch is gas or loose stools if a dog wolfs down a large raw helping all at once.
Horses None
Horses are the one to keep away from it, since NC State Extension flags brassicas as a poor fit for their diet in any quantity. A stray leaf does no harm, but do not make it a regular treat.
Rabbits None
Rabbits take small servings of the leafy greens in stride. Bring it in slowly and keep portions modest, since too much rich brassica at once can leave a bunny gassy.
Livestock None
Cattle, goats, and sheep can graze the leaves with nothing to fear. Like any brassica, a diet of it alone can upset rumen digestion, so keep it as part of the mix rather than the whole meal.
Birds None
Backyard hens and other birds peck eagerly at the leaves and the bolted flowers. In moderation it makes a wholesome green for them.
People Safe
Bok choy is grown to be eaten and is dead safe in the kitchen, raw in salads or cooked into a stir-fry. The only thing to flag is a steady habit of large raw amounts, owing to the natural goitrogens shared across the cabbage family.
No special handling needed; safe to grow in household gardens.
Varieties
Bok choy shows up in white-stemmed and green-stemmed forms and in full-size and baby types. These are the ones worth knowing by name.
Shanghai (green-stem) type
The Shanghai type, called Shanghai Qing in China, sports spoon-shaped leaves on pale green stalks instead of white ones and is often grabbed young as baby bok choy.
Dwarf types
Dwarf types pack a fast crop into tight space, topping out around 6 inches, sitting as close as 12 inches apart, and maturing in a hurry.
'Joi Choi'
'Joi Choi' is a vigorous white-stemmed hybrid that growers chase for its slow bolting and its easy way with both cold and warm spells.
'Mei Qing Choi'
'Mei Qing Choi' is a green-stemmed baby pak choi hybrid that shrugs off bolting like a champ.
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 it is about as easy and rewarding as sowing gets, with a fresh row ready to fire off 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 starting it a breeze. Drop the seed a quarter to half an inch deep in early spring, or again around July for a fall crop, and watch it pop in 4 to 10 days in cool soil. Thin to one plant every 6 to 12 inches by variety, then it is 3 to 4 weeks to transplant size and 40 to 60 days to a full head. Fire off a fresh row every couple of weeks and you will never run short.
Myths
When bok choy shoots to seed, the whole plant is a write-off headed straight for the trash heap.
Hold off on tossing it, because a bolting plant is still great food 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 a tasty bonus all their own.
No blazing sun all day means no bok choy; the crop simply refuses to grow with anything less.
Full sun grows the fastest, fullest heads, sure, but it is no make-or-break. As little as 2 hours of direct sun a day still yields usable heads, just at a more easygoing pace.