Choy sum succession planting schedule for year round Asian green harvests in raised beds

Achieving continuous choy sum harvests in raised beds throughout the year hinges on understanding its temperature preferences, managing seasonal challenges, and maintaining a disciplined sowing rhythm. Choy sum thrives in cool to mild weather, ideally between 55-75°F (13-24°C), and tends to bolt rapidly when temperatures climb or day lengths extend. Raised beds offer superior drainage and soil control, which are advantageous for this crop.

For consistent production, plan to sow small batches of choy sum seeds every two to three weeks. This staggered approach ensures that as one crop is harvested, the next is already growing to maturity. Prepare your raised bed soil by enriching it with well-rotted compost, ensuring it is loose and well-draining. Direct sow seeds about half an inch deep, spacing them 4-6 inches apart in rows 8-12 inches apart. Consistent moisture is paramount from sowing through harvest.

Spring (Early March to Mid-May): This is the prime growing season for choy sum in most temperate regions. Begin your succession planting as soon as the danger of hard frost passes. The mild temperatures and increasing daylight promote vigorous growth without immediate bolting pressure. Sow a new section of your raised bed every two weeks. Expect harvests within 30-45 days. Keep the soil uniformly moist, as any dry spell can trigger premature bolting.

Summer (Late May to Early September): This period is challenging due to high temperatures and long days, which cause choy sum to bolt quickly and become bitter. Select heat-tolerant varieties. Crucially, position your raised beds to receive afternoon shade or use 30-50% shade cloth. Shorten sowing intervals to every 1-2 weeks, as plants mature and bolt faster. Water deeply and consistently, potentially twice daily during heatwaves, to keep the root zone cool and moist. Mulching with straw or shredded leaves helps retain moisture and regulate soil temperature. Harvest plants young, often as baby greens or before flower stalks fully emerge, for best flavor.

Autumn (Mid-September to Late November): As temperatures begin to cool and day lengths shorten, autumn becomes another excellent season for choy sum. Conditions mirror spring, often with less pest pressure. Resume your 2-3 week sowing schedule. The plants will grow steadily, producing tender leaves and stems. Continue to ensure consistent soil moisture in your raised beds. Harvests will typically occur 30-50 days after sowing. Be prepared for potential early frosts by having lightweight row covers or cloches ready to deploy over your raised beds, extending the harvest window well into late autumn.

Winter (Early December to Late February): Year-round choy sum is achievable in raised beds, especially in USDA zones 8 and above, or with significant protection in colder climates. In milder zones, sow every 3-4 weeks; growth will be slower. For colder regions, use unheated cold frames, low tunnels, or thick fabric row covers over your raised beds to insulate plants from freezing temperatures and cold winds. Choose cold-hardy varieties. Growth will be significantly slower, extending harvest times to 50-70 days or more.