When to plant bok choy by city
Start bok choy indoors 4–6 weeks before your last frost, plant them out up to 2 weeks before your last frost, or sow seed outdoors 2–4 weeks before your last frost. For a fall crop, sow 6–8 weeks before your first fall frost. Here is what that means for 2027 in cities across the US, using each city’s average frost dates (NOAA 1991–2020). Pick the city with the climate most like yours, or enter your ZIP code above.
| City | Last frost | Start indoors | Plant out | Sow outdoors | Fall crop |
|---|---|---|---|---|---|
| Seattle, WA (9a) | Mar 13 | Jan 30 – Feb 13 | Feb 27 – Mar 13 | Feb 13–27 | Sep 22 – Oct 6 |
| Portland, OR (8b) | Feb 25 | Jan 14–28 | Feb 11–25 | Jan 28 – Feb 11 | Oct 6–20 |
| Sacramento, CA (9b) | Jan 12 | Dec 1–15 | Dec 29 – Jan 12 | Dec 15–29 | Oct 21 – Nov 4 |
| Phoenix, AZ (10a) | Jan 5 | Nov 24 – Dec 8 | Dec 22 – Jan 5 | Dec 8–22 | Nov 8–22 |
| Salt Lake City, UT (7b) | Mar 31 | Feb 17 – Mar 3 | Mar 17–31 | Mar 3–17 | Sep 13–27 |
| Denver, CO (6a) | Apr 30 | Mar 19 – Apr 2 | Apr 16–30 | Apr 2–16 | Aug 17–31 |
| Dallas, TX (8b) | Mar 2 | Jan 19 – Feb 2 | Feb 16 – Mar 2 | Feb 2–16 | Oct 4–18 |
| Minneapolis, MN (5a) | Apr 23 | Mar 12–26 | Apr 9–23 | Mar 26 – Apr 9 | Aug 21 – Sep 4 |
| Kansas City, MO (6b) | Apr 4 | Feb 21 – Mar 7 | Mar 21 – Apr 4 | Mar 7–21 | Sep 7–21 |
| Chicago, IL (6b) | Apr 10 | Feb 27 – Mar 13 | Mar 27 – Apr 10 | Mar 13–27 | Sep 10–24 |
| Columbus, OH (6b) | Apr 20 | Mar 9–23 | Apr 6–20 | Mar 23 – Apr 6 | Aug 29 – Sep 12 |
| Nashville, TN (7b) | Apr 1 | Feb 18 – Mar 4 | Mar 18 – Apr 1 | Mar 4–18 | Sep 5–19 |
| Atlanta, GA (8a) | Mar 24 | Feb 10–24 | Mar 10–24 | Feb 24 – Mar 10 | Sep 13–27 |
| Raleigh, NC (8a) | Mar 28 | Feb 14–28 | Mar 14–28 | Feb 28 – Mar 14 | Sep 13–27 |
| Philadelphia, PA (7b) | Mar 30 | Feb 16 – Mar 2 | Mar 16–30 | Mar 2–16 | Sep 22 – Oct 6 |
| Boston, MA (7a) | Apr 4 | Feb 21 – Mar 7 | Mar 21 – Apr 4 | Mar 7–21 | Sep 14–28 |
In frost-free parts of Florida, southern California and the Gulf Coast, timing is about heat instead: grow bok choy from fall through winter.
Bok choy spacing
In a square-foot bed, plant 4 per square foot. In traditional rows, space plants about 6 inches apart with 18 inches between rows.
Baby bok choy is ready in about 30 days.
How to grow bok choy
Bok choy (pak choi) is a fast, mild Asian green with crisp white or green stems. Baby plants are ready in about 30 days and full heads in 45–60, so it fits neatly between other crops. It is easiest in spring and fall, because cold snaps and heat both push it to bolt.
Sun and soil
Full sun to part shade, in moist, well-drained soil amended with compost, pH 6.0–7.5. It has shallow roots, so keep the soil evenly moist.
Planting
- Direct-sow ¼–½ inch deep 2–4 weeks before the last frost, once soil is around 45°F.
- Or start seeds indoors 4–6 weeks before transplanting and set plants out from 2 weeks before the last frost up to the frost date.
- Thin or space to 6 inches apart in rows 18 inches apart. Baby types can go closer.
- For fall, sow 6–8 weeks before the first fall frost; fall crops bolt least.
Care
- Water regularly; dry soil makes stems tough and triggers bolting.
- Feed with a little nitrogen for fast, tender growth.
- Protect young transplants from hard frost and long cold spells, which can cause bolting later.
- Use row cover against flea beetles and caterpillars.
Harvest
Cut baby bok choy when it is 4–6 inches tall, or harvest full heads at the base when they reach full size, usually 45–60 days from seed. You can also pick outer leaves one at a time. If a flower stalk appears, harvest the whole plant right away.
Common problems
- Flea beetles: Tiny holes in leaves. Row cover from sowing is the most effective control.
- Bolting: Triggered by long days, heat and cold stress. Grow in spring and fall and harvest promptly.
- Slugs and snails: Ragged holes and slime trails. Hand-pick at night, use traps, and avoid soggy mulch around plants.
- Aphids and cabbageworms: Spray aphids off with water; hand-pick caterpillars or use Bt.
Varieties to try
- 'Joi Choi' — large heads with white stems, slow to bolt
- 'Toy Choy' — miniature type for baby bok choy
- 'Black Summer' — dark green leaves, more heat tolerant
Crop rotation
Bok choy belong to the cabbage family (Brassicaceae). Clubroot and cabbage pests build up in the soil. Rotate for at least 3 years. Relatives that count as the same family for rotation: broccoli, cauliflower, cabbage, kale, brussels sprouts, radish, turnip, arugula, kohlrabi.
Frequently asked questions
When should I plant bok choy?
What grows well with bok choy?
How far apart should I plant bok choy?
How long do bok choy take to grow?
Can bok choy handle frost?
Sources
- Frost dates: NOAA National Centers for Environmental Information, U.S. Climate Normals 1991–2020.
- Hardiness zones: 2023 USDA Plant Hardiness Zone Map, USDA-ARS and PRISM Climate Group, Oregon State University.
- Planting windows and spacing: Vegetable Planting Guide (GardenNotes #720), Colorado State University Extension, and other land-grant extension guides.
- Gardening with Companion Plants (EM128E), Linda Chalker-Scott, Washington State University Extension, 2023
- Brassica flea beetles, UMass Amherst Vegetable Program
- Trap Cropping, Washington State University Extension Master Gardener Program
- Trap cropping: a review of the state of the art, Sarkar et al., 2018 (open-access review)
- Brassica rapa Chinensis Group (bok choy) — NC State Extension Plant Toolbox