If you’re planning your vegetable garden, knowing when to grow bok choy is the first step to a great harvest. This crisp, versatile green thrives in specific conditions, and timing your planting correctly makes all the difference.
Bok choy, also known as pak choi, is a cool-season crop. It prefers mild temperatures and can bolt, or go to seed, quickly if stressed by heat or fluctuating weather. This guide will walk you through the best planting seasons for your climate, so you can enjoy a steady supply of its tender stalks and leaves.
When to Grow Bok Choy
The perfect planting time depends almost entirely on your local climate. There are two main growing windows: spring and fall. For most gardeners, fall is often the easiest and most productive season.
Spring Planting Season
In spring, the goal is to get bok choy established before summer heat arrives. You need to work around the last frost date.
- Start seeds indoors 4 to 6 weeks before your last expected spring frost date. This gives seedlings a head start.
- Transplant seedlings or sow seeds directly in the garden 1 to 2 weeks before the last frost date. Bok choy can handle a light frost.
- In regions with short, cool springs, direct sowing is often succesful.
The challenge with spring is that warming days can trigger bolting. Choosing slow-bolt varieties can help extend your harvest window.
Fall Planting Season
Fall is the premier time for growing bok choy. Cooler, stable temperatures and fewer pests create ideal conditions.
- Calculate your planting date by counting backwards from your first average fall frost date.
- Start seeds indoors or sow directly in the garden 6 to 8 weeks before that first frost.
- You can continue succession planting every two weeks for a continuous harvest.
As temperatures drop, bok choy grows sweet and tender. It can survive hard frosts with protection, like a cold frame or row cover.
Climate-Specific Planting Calendars
Here’s a quick reference to adjust the timing for your area:
Northern Climates (Colder Zones)
With shorter growing seasons, focus on one stellar crop in fall. For spring, wait until the ground is workable and use transplants. A mid-summer planting for fall harvest is your best bet.
Southern Climates (Warmer Zones)
You can grow bok choy in winter and early spring. Avoid summer entirely. Plant in late fall for a winter harvest, or in very early spring as soon as the ground thaws. Partial afternoon shade is beneficial as weather warms.
Coastal/Mild Climates
You have the most flexibility. You can often grow bok choy nearly year-round with succession planting. The primary times to avoid are the peak heat of midsummer and the coldest, wettest part of winter.
Step-by-Step Planting Guide
Once you’ve nailed the timing, follow these steps for healthy plants.
1. Choosing Your Variety
Select a type suited to your season. For spring, pick ‘Shanghai’ or ‘Joi Choi’ which are slower to bolt. For fall, you have more options like standard ‘Michihli’ or dwarf ‘Toy Choy’.
2. Preparing the Soil
Bok choy needs fertile, well-draining soil. Work in 2-3 inches of compost or well-rotted manure before planting. The soil pH should be slightly acidic to neutral (6.0-7.0). Good nutrition prevents stress that leads to bolting.
3. Sowing Seeds
Plant seeds ¼ to ½ inch deep. Space them about 1 inch apart in rows, with rows 12-18 inches apart. You’ll thin them later. Keep the seedbed consistently moist for good germination, which takes 4-10 days.
4. Thinning Seedlings
Once seedlings are a few inches tall, thin them to the proper spacing. For smaller varieties, leave 6 inches between plants. For full-sized heading types, allow 10-12 inches. The thinned seedlings are delicious in salads!
5. Watering and Feeding
Provide 1-1.5 inches of water per week. Consistent moisture is key; drought stress causes bitterness and bolting. A side-dressing of a balanced organic fertilizer 3 weeks after transplanting gives them a boost.
Common Problems and Seasonal Solutions
Each season brings its own challenges. Here’s how to manage them.
Preventing Bolting (Going to Seed)
Bolting is the number one issue. It’s triggered by:
- Long, warm days (over 13 hours of daylight).
- Temperature swings, especially warm spells after cool periods.
- Underwatering or root disturbance.
Solutions: Plant at the right time, use row covers to moderate temperature, choose bolt-resistant varieties, and water consistently. If a plant starts to bolt, harvest it immediately—it’s still edible.
Pest Management by Season
Pests vary with the time of year.
- Spring/Summer: Flea beetles and cabbage worms are prevalent. Use floating row covers as a physical barrier from day one. Check undersides of leaves regularly.
- Fall: Aphids and slugs can be problematic. A strong spray of water dislodges aphids. Hand-pick slugs or use iron phosphate bait.
Encourage beneficial insects like ladybugs by planting flowers nearby. Healthy plants are more resilient, so good soil and water practises are your first defense.
Harvesting Your Bok Choy
You can harvest at any stage. For baby bok choy, cut whole plants about 4-6 inches tall. For full-sized heads, wait until they are firm and 12-18 inches tall, depending on variety.
Use a sharp knife to cut the plant at the base. You can also harvest individual outer leaves as needed, which allows the center to keep growing. For the best flavor, harvest in the morning when plants are most hydrated.
Extending the Season
With a little effort, you can stretch your harvest beyond the typical seasons.
- Row Covers & Cold Frames: These protect plants from frost and light freezes in fall, allowing you to harvest weeks longer. In spring, they warm the soil slightly and protect from wind.
- Shade Cloth: In spring or warm climates, a 30-40% shade cloth can lower temperatures and delay bolting during unseasonable heat spells.
- Container Growing: Pots can be moved into shade or shelter as needed, giving you more control over the plants environment.
FAQ: Your Bok Choy Planting Questions Answered
Can you grow bok choy in summer?
It’s not ideal. Summer heat usually causes it to bolt quickly and become bitter. In cool-summer climates, you might succeed with shade cloth and ample water, but spring and fall are more reliable.
How late can you plant bok choy?
You can plant up until about 4-6 weeks before your first hard fall frost. Use quick-maturing varieties and be prepared to protect them with covers as temperatures drop for a late harvest.
Does bok choy come back every year?
No, bok choy is an annual plant. It completes its life cycle—from seed to harvest to seed—in one growing season. You need to replant it for each crop.
Can bok choy survive frost?
Yes, it can survive light frosts (down to about 28-32°F) quite well. In fact, a light frost can improve its flavor, making it sweeter. A hard, prolonged freeze will damage the leaves unless it’s protected.
What is the best month to plant bok choy?
There is no universal “best month.” It depends on your zone. For many, late summer (August) for a fall harvest is optimal. In the South, late winter (February) for a spring harvest works well. Always base it on your frost dates.
Getting the timing right is the secret to growing fantastic bok choy. By aligning your planting with the cool seasons of spring and fall, you provide the conditions this vegetable loves. Remember, consistent care—especially watering—will keep your plants stress-free and slow to bolt. With this guide, you’re ready to plan your planting calendar and look forward to a plentiful harvest of crisp, homegrown bok choy.