Cabbage Seeds,
Sapporo Giant #4

Sapporo Giant cabbage is ideally grown in cooler seasons. Start seeds indoors 6-8 weeks before the last expected frost date for a spring harvest. For a fall harvest, sow seeds in mid-summer. It typically takes about 65-100 days to mature, depending on the growing conditions. If you’re not sure how to find your first and last frost dates, consult our blog post 'Our Experts Answer Questions, Share Resources.'

Sow the seeds about 1/4 inch deep in a seed-starting mix if starting indoors. Once seedlings develop their first set of true leaves, transplant them outdoors, spacing them about 36 inches apart due to the large size of the heads. This cabbage variety prefers well-draining, fertile soil with a slightly acidic to neutral pH (6.0-7.5).

To grow Sapporo Giant successfully, ensure it receives full sun, about 6-8 hours a day. Consistent watering is crucial; the plants should receive about 1-1.5 inches of water per week. Deep watering is recommended to promote strong root growth. Mulching around the base can help retain soil moisture and prevent weeds. Fertilize regularly with a balanced fertilizer to support its large size.

• If you plan to save seeds, isolate plants from other members of the cabbage species (kale, collards, broccoli, Brussels sprouts and cauliflower) by up to one mile to avoid cross pollination.
• Cabbage is biennial, blooming only after experiencing a winter's chill, and will require overwintering with heavy mulch and row cover in cool winter areas.
• For those with very harsh winters, consider digging up and placing in a root cellar until hard frost has passed.
• In the second season, when flowers have passed and seed pods have dried, dig up the plants and hang upside down to dry.
• Dried pods can be placed in a sack and crushed to release seeds. Remove chaff and detritus.
• Place seeds in a glass jar and refrigerate for up to 5 years.