Growing your own vegetables is rewarding, and few are as quick and satisfying as choy sum. This crisp and tender green is a staple in Asian cooking, and it thrives in a home garden with the right care. Let’s look at how you can grow a fantastic crop from seed to harvest.
Choy sum, sometimes called Chinese flowering cabbage, is prized for its sweet, mild flavor and succulent stems. It’s faster to mature than many brassicas, often ready in just 40-50 days. You get a lot of food from a small space, making it perfect for raised beds or containers.
Choy Sum – Crisp and Tender Greens
This heading says it all—the goal is to produce those perfect, crisp and tender greens. Achieving that texture depends on three things: rapid growth, consistent water, and a timely harvest. Slow-grown or stressed choy sum can become tough and bitter.
Why You Should Grow Choy Sum
It’s a versatile and forgiving plant for gardeners of all levels. Here’s why it deserves a spot in your plot:
- Speed: You’ll be harvesting in well under two months.
- Succession Planting: You can grow multiple crops in one season, from early spring to fall.
- Space-Efficient: Plants can be spaced quite closely together.
- Disease Resistance: It has fewer common pest problems than some cabbages.
- Dual Purpose: You can eat the leaves, stems, and yellow flowers.
Choosing the Best Variety for Your Garden
Not all choy sum is exactly the same. Selecting a variety suited to your climate and season improves your chances for those crisp stems.
- Green Stem Types: The most common, with vivid green leaves and stems. They are reliable and heat-tolerant.
- White Stem Types: Often called bok choy sum, they have thicker, very pale stems that are exceptionally sweet and crisp.
- Look for varieties labeled as “bolt-resistant” for spring and summer planting to prevent early flowering.
Planting Your Choy Sum: Step-by-Step
Getting the start right is crucial for healthy plants. Follow these simple steps.
1. Timing and Site Selection
Choy sum prefers cool to moderate weather. It can handle light frost but bolts in prolonged heat.
- Spring: Direct sow 2-4 weeks before your last frost date.
- Fall: Sow seeds about 6-8 weeks before your first fall frost for the sweetest crop.
- Site: Choose a spot with full sun to light afternoon shade. Soil should be fertile and drain well.
2. Preparing the Soil
These greens are moderate feeders. They need good nutrition for fast growth.
- Work in 2-3 inches of compost or well-rotted manure into the top 6 inches of soil.
- A balanced organic fertilizer mixed in at planting gives them a good boost.
- Ensure the soil pH is between 6.0 and 7.0 for optimal nutrient uptake.
3. Sowing Seeds Directly
Choy sum transplants okay, but it grows best sown directly where it will mature.
- Make shallow furrows about 1/2 inch deep.
- Sow seeds thinly, spacing them about 1 inch apart.
- Cover lightly with soil and water gently.
- Space rows 12-18 inches apart.
Seeds typically germinate in 4-7 days. Thin seedlings to 6 inches apart when they have a few true leaves. You can eat the thinnings!
Caring for Your Growing Plants
Consistent care is the secret to preventing toughness and ensuring a tender harvest.
Watering Needs
Never let choy sum dry out completely. Fluctuating moisture causes stress.
- Provide 1-1.5 inches of water per week, more during hot, dry spells.
- Water at the base to keep leaves dry and prevent disease.
- Mulch with straw or grass clippings to help retain soil moisture and suppress weeds.
Fertilizing for Fast Growth
A light feed halfway through the growing cycle supports rapid development.
- Apply a liquid fertilizer, like fish emulsion or a balanced organic blend, 3 weeks after sowing.
- This mid-season feed promotes strong leaf and stem growth without delay.
Pest and Disease Watch
While relatively trouble-free, keep an eye out for a few common issues.
- Flea Beetles: These tiny jumping insects make small holes in leaves. Use floating row covers from planting as a barrier.
- Cabbage Loopers: Handpick these green caterpillars or use an organic Bt (Bacillus thuringiensis) spray.
- Bolting: If the plant sends up a flower stalk too early, it’s usually due to heat or stress. Harvest immediately, as the stems remain edible.
How and When to Harvest
Harvesting at the peak moment is what delivers on the promise of crisp and tender greens.
- The best time to harvest is in the cool of the morning, when plants are most hydrated.
- Plants are typically ready 40-50 days after sowing, when about 12-15 inches tall.
- You can harvest the whole plant by cutting it at the base with a sharp knife, about an inch above the soil.
- For a “cut-and-come-again” approach, harvest the larger outer leaves first, allowing the center to continue growing.
Don’t wait to long, as over-mature stems can become fibrous. If yellow flowers appear, harvest right away—the stems are still great to eat.
Storing and Using Your Harvest
Freshness is key to maintaining that wonderful texture you worked so hard for.
- For best quality, eat choy sum the same day you harvest it.
- To store, wrap unwashed bunches in a damp paper towel and place in a perforated plastic bag in the refrigerator crisper. It will keep for 3-5 days.
- To prepare, rinse thoroughly. The entire plant—leaf, stem, and flower—is edible. Stir-frying, steaming, or adding to soups are classic methods that preserve its crisp-tender quality.
Common Problems and Simple Solutions
Here’s a quick guide to troubleshooting your crop.
- Slow, Stunted Growth: Usually caused by poor soil, lack of nutrients, or overcrowding. Thin plants and apply a liquid feed.
- Yellowing Leaves: Can indicate overwatering, poor drainage, or a nitrogen deficiency. Check soil moisture and consider a nitrogen-rich fertilizer.
- Woody, Bitter Stems: This is a classic sign of slow growth due to stress, heat, or an overdue harvest. Improve watering practices and harvest younger.
FAQ About Growing Choy Sum
What is the difference between choy sum and bok choy?
Choy sum has slimmer, rounder stems and produces yellow flowers. Bok choy forms a more pronounced, celery-like cluster of wide white stems with dark green leaves. The both have a mild flavor, but choy sum stems are more tender.
Can I grow choy sum in containers?
Absolutely. Use a pot at least 8-10 inches deep. Ensure it has drainage holes and use a quality potting mix. Water container plants more frequently, as they dry out faster.
How do I stop my choy sum from flowering so quickly?
Bolting is triggered by long days and warm temperatures. Plant bolt-resistant varieties for summer, and focus on spring and fall crops for the best results. Consistent watering and mulching to keep soil cool can also help delay it.
Can I save seeds from my choy sum plants?
Yes, but it requires planning. Let some of your best plants flower and go to seed. The seed pods will dry on the plant. Collect them before they split open, and store the seeds in a cool, dry place for next season. Remember, if you grow more than one brassica variety, they may cross-pollinate.
What are good companion plants for choy sum?
Plant it with other quick-growing greens like lettuce or spinach. Aromatics like onions, garlic, or herbs like dill and mint can help deter some pests. Avoid planting it in the same spot where other cabbage family plants grew the previous year to reduce disease risk.
Growing choy sum is a straightforward way to add a delicious, productive green to your garden. By focusing on quick growth through good soil, steady water, and timely picking, you’ll be rewarded with that perfect combination of crisp stems and tender leaves. Give it a try this season—you might just find it becomes a regular in your garden plan.