There’s something special about growing your own greens, and few are as rewarding as choy sum. To get that perfect choy sum – crisp and vibrant green from your garden, a few key steps make all the difference. This guide walks you through everything from seed to harvest, ensuring you get the best flavor and texture from this delicious vegetable.
Choy sum, sometimes called Chinese flowering cabbage, is a staple in Asian cooking. It’s known for its tender stems, mild flavor, and those beautiful yellow flowers. But the real prize is when the leaves and stalks are crisp and the color is a deep, vibrant green. That’s a sign of perfect health and freshness.
Choy Sum – Crisp and Vibrant Green
Achieving that ideal crisp, vibrant green harvest isn’t just luck. It’s the direct result of understanding the plant’s needs and creating the right conditions in your garden. When you get it right, the difference is remarkable.
Why Choy Sum is a Gardener’s Best Friend
This vegetable is a fantastic choice for both beginners and experienced gardeners. It grows quickly, often ready for harvest in just 40-50 days from seeding. It also doesn’t require a huge amount of space, making it perfect for small gardens or even containers on a sunny balcony.
Here are some of its top benefits:
* Fast growth cycle for multiple harvests in a season.
* High yield in a compact footprint.
* Excellent cold tolerance for spring and fall planting.
* Few serious pest problems compared to other brassicas.
* Adds beautiful structure and color to the vegetable patch.
Starting Right: Seed Selection and Soil Prep
Your journey to crisp choy sum begins before you even put a seed in the ground. Choosing the right variety and preparing your soil sets the foundation for everything that comes after.
Picking Your Seeds
Look for reputable seed companies. Common varieties include ‘Green Lance’ and ‘Springtime’. For something a bit different, you might try purple-stemmed varieties, though our focus remains on that classic green color. Always check the days to maturity on the packet to plan your planting schedule.
Creating the Perfect Soil Bed
Choy sum thrives in rich, well-draining soil. It prefers a slightly acidic to neutral pH, between 6.0 and 7.0. Heavy, clay-heavy soil will lead to poor growth and less crisp stems.
Follow these steps to prepare your bed:
1. Loosen the soil to a depth of at least 12 inches.
2. Mix in a generous 3-4 inch layer of well-rotted compost or aged manure.
3. Add a balanced, all-purpose organic fertilizer according to package directions.
4. Rake the bed smooth, removing any large clumps or stones.
Planting Your Choy Sum for Success
You have two main options for starting your crop: direct seeding or transplanting. Both can work well, depending on your climate and preference.
Direct Seeding into the Garden
This is often the easiest method. Sow seeds about ½ inch deep and 1 inch apart in rows that are 12-18 inches apart. Once the seedlings are a few inches tall, you’ll thin them to about 6-8 inches apart. Don’t feel bad about thinning—those tender thinnings are perfect for a salad or stir-fry!
Starting Seeds Indoors for Transplants
If you have a short spring or want to get a head start, begin seeds indoors 3-4 weeks before your last expected frost. Use cell trays or small pots with a good seed-starting mix. Keep them moist and provide plenty of light. Harden off the seedlings for a week before transplanting them into the garden at that same 6-8 inch spacing.
The Care Guide: Water, Food, and Sun
Consistent care is the secret to preventing bitterness and encouraging that desirable crisp texture. Choy sum is not a “plant and forget” crop, but its needs are simple.
Watering for Consistent Growth
The goal is even, consistent soil moisture. Fluctuations between dry and wet soil cause stress, leading to tougher stems and a stronger flavor. Water deeply at the base of the plants, ideally in the morning. Avoid overhead watering in the evening, as damp leaves overnight can invite fungal diseases. A soaker hose or drip irrigation system is ideal.
Feeding Your Plants
While your initial soil prep provides a good base, choy sum is a quick grower and benefits from a mid-season nutrient boost. About 3 weeks after planting or transplanting, side-dress the plants with a nitrogen-rich fertilizer. Blood meal, fish emulsion, or a balanced organic vegetable fertilizer work great. This keeps the growth steady and the leaves vibrant.
Sun and Temperature Needs
Choy sum prefers full sun, which means at least 6 hours of direct sunlight daily. In very hot summer climates, it appreciates a little afternoon shade to prevent it from bolting (flowering prematurely) too quickly. It grows best in cooler conditions, with ideal temperatures between 50°F and 75°F. This makes it a perfect spring or fall crop in many regions.
Keeping Pests and Problems at Bay
Healthy choy sum is usually trouble-free, but a few pests can show up. The key is early identification and gentle intervention.
Common issues include:
* Flea Beetles: These tiny jumping insects create small shot-holes in leaves. Use floating row covers as a barrier from day one.
* Cabbage Loopers: These green caterpillars can munch on leaves. Handpick them or use an organic Bt (Bacillus thuringiensis) spray.
* Aphids: Small clusters of green or black insects on stems and undersides of leaves. A strong blast of water from the hose often knocks them off.
* Bolting: When the plant sends up a flower stalk too early, usually due to heat or stress. The stems can become woodyer. The best prevention is planting at the right time and keeping plants well-watered.
How and When to Harvest for Peak Crispness
This is the most important part! Harvesting at the right moment is what ensures that choy sum – crisp and vibrant green makes it to your kitchen. Timing is everything.
The best time to harvest is when the flower buds are just beginning to form and are still tightly closed. The stems should be firm, and the leaves should be a deep, uniform green. If the yellow flowers have fully opened, you’ve waited a bit too long—the stems may start to loose their perfect crispness.
Here’s the proper way to harvest:
1. Use a clean, sharp knife or scissors.
2. Cut the main stem about an inch above the soil line. This method often encourages new, smaller shoots to grow from the base for a second, “cut-and-come-again” harvest.
3. Alternatively, you can harvest individual outer leaves and stems as needed, allowing the center to continue growing.
4. Immediately take your harvest inside to cool it down.
Post-Harvest Handling for Maximum Freshness
What you do after harvesting is just as crucial as how you grow it. Proper handling preserves that texture you worked so hard for.
Follow this routine:
1. Cool Quickly: Bring your harvest inside right away. If the leaves are wilting slightly, you can submerge the whole stems in a bowl of cool water for 10-15 minutes to re-crisp them.
2. Dry Thoroughly: Gently spin or pat the leaves dry. Excess moisture speeds up decay.
3. Store Correctly: Place the dry choy sum in a perforated plastic bag or a loose plastic bag with a paper towel inside. Store it in the crisper drawer of your refrigerator. Properly stored, it should stay crisp for 4-7 days.
Growing Choy Sum in Containers
No garden bed? No problem. Choy sum adapts wonderfully to container growing, making it accessible to almost anyone.
Choose a pot that is at least 12 inches deep and wide. Ensure it has excellent drainage holes. Use a high-quality potting mix, not garden soil, and consider mixing in some extra compost for nutrients. Container plants dry out faster, so you’ll need to check the moisture daily, especially as the plants get bigger. A monthly feed with a liquid fertilizer will keep them growing strong.
Troubleshooting Common Growing Issues
Sometimes, despite your best efforts, things don’t go perfectly. Here’s how to diagnose and fix common problems.
* Yellowing Leaves: This is often a sign of overwatering or poor drainage. Check that your soil or container drains well. It could also indicate a nitrogen deficiency—try a liquid feed.
* Spindly, Thin Stems: The plants are not getting enough light. Move them to a sunnier location or thin them out more to reduce competition.
* Bitter Flavor: Usually caused by heat stress or inconsistent watering. Ensure even moisture and provide shade during the hottest part of the day in summer.
* Holes in Leaves: Likely insect damage. Inspect the undersides of leaves for pests and take appropiate action as described earlier.
FAQs About Growing Choy Sum
Q: What’s the difference between choy sum and bok choy?
A: They are related but different. Bok choy forms a more pronounced, celery-like white stalk with dark green leaves clustered at the top. Choy sum has slimmer, greener stems and tends to produce prominent yellow flowers. The texture and flavor are also distinct.
Q: Can I grow choy sum year-round?
A: In mild climates, you can grow it almost year-round. In areas with hot summers or freezing winters, it’s best as a spring and fall crop. It tolerates light frosts quite well.
Q: How do I stop it from flowering so fast?
A: Bolting (premature flowering) is triggered by long days and high temperatures. The best strategy is to plant it so it matures in the cool weather of spring or autumn. Keeping the soil consistently moist also helps delay bolting.
Q: My choy sum is tall and leggy. What went wrong?
A: This is almost always due to insufficient sunlight. The plant stretches to find more light. Ensure it gets at least 6 hours of direct sun. Overcrowding can also cause this, so thin your seedlings properly.
Q: Can I save seeds from my choy sum plants?
A: Yes, but with caution. Choy sum will cross-pollinate with other brassicas like mustard greens or turnips if they are flowering nearby. To save pure seeds, you need to isolate the plants. Let the flowers fade and the seed pods dry on the plant before collecting them.
Growing the perfect choy sum is a simple joy. It responds so clearly to good care, rewarding you with those crisp stems and vibrant green leaves that are so much better than anything you can buy. With the right timing, consistent moisture, and a watchful eye for pests, you’ll be harvesting basketfuls of this tasty green. Remember, the path to a great harvest starts with good soil and ends with a timely harvest. Give it a try in your next garden season.