How To Grow Giant Cabbage

Giant cabbage heads start with soil that drains well and stays nutrient-rich. If you have ever wondered how to grow giant cabbage, the process is simpler than you think—but it does require patience and attention to detail. Whether you want to impress your neighbors or compete at the county fair, these steps will guide you from seed to monster-sized head.

Growing a cabbage that weighs 50 pounds or more is not about luck. It is about soil preparation, variety selection, watering, and timing. Let’s break down each step so you can grow your own giant cabbage.

Before you plant a single seed, you need to understand the basics. Giant cabbages are not ordinary grocery-store cabbages. They are specific varieties bred for size, and they need extra care from day one.

Choose The Right Giant Cabbage Variety

Not all cabbage seeds are equal. For giant heads, you need a variety known for massive growth. The most popular choices include:

Mammoth Red Rock – Can reach 40–50 pounds with deep red color
Giant Jersey Wakefield – Heirloom variety, known for large pointed heads
O-S Cross – A hybrid that often produces 30–40 pound cabbages
Kalahari – Bred specifically for size, can exceed 60 pounds

Buy seeds from a reputable supplier. Avoid generic seed packets labeled only “cabbage.” You want a named giant variety.

Prepare The Soil Months In Advance

Giant cabbages are heavy feeders. They need rich, deep soil with plenty of organic matter. Start preparing your bed at least 4–6 weeks before planting.

Choose a sunny spot with at least 6–8 hours of direct sunlight daily.
Dig the soil to a depth of 12–18 inches. Remove rocks and roots.
Mix in 4–6 inches of well-rotted compost or aged manure.
Add a balanced slow-release fertilizer (10-10-10) according to package directions.
Test the soil pH. Cabbages prefer a pH between 6.0 and 7.5. Add lime if needed to raise pH.

Good drainage is critical. If your soil stays soggy, consider building a raised bed. Standing water rots roots and stunts growth.

Start Seeds Indoors For A Head Start

Giant cabbages need a long growing season. In most climates, you should start seeds indoors 6–8 weeks before the last frost date.

Use seed-starting mix in small pots or trays.
Plant seeds ¼ inch deep.
Keep soil moist but not wet.
Provide bright light (grow lights work best) for 14–16 hours daily.
Maintain temperatures around 60–65°F at night, 70–75°F during the day.

Once seedlings have two sets of true leaves, transplant them into larger pots (4-inch or bigger). This encourages strong root growth before moving outdoors.

Harden Off Seedlings Gradually

About two weeks before transplanting, start hardening off your seedlings. This means slowly exposing them to outdoor conditions.

Place seedlings outside in a sheltered spot for 1–2 hours on the first day.
Increase exposure by 1–2 hours each day.
Bring them indoors at night if temperatures drop below 45°F.
After 10–14 days, they should be ready for full sun and wind.

Do not skip this step. Sudden exposure to sun and wind can shock young plants and stunt their growth.

Transplant At The Right Time

Transplant your seedlings outdoors after the last frost date, when soil temperatures reach at least 50°F. Space them generously—giant cabbages need room to spread. Plant each seedling 3–4 feet apart in rows spaced 4 feet apart.

Dig a hole slightly larger than the root ball.
Mix a handful of compost into the bottom of the hole.
Place the seedling so the first set of leaves is just above soil level.
Firm the soil gently around the roots.
Water thoroughly after planting.

If you plant too close, the cabbages will compete for nutrients and produce smaller heads. Give them space to grow.

Water Consistently And Deeply

Giant cabbages need steady moisture. Inconsistent watering causes cracked heads or slow growth. Aim for 1–2 inches of water per week, including rainfall.

Water deeply at the base of the plant, not overhead. Wet leaves invite disease.
Use drip irrigation or a soaker hose for best results.
Mulch around the plants with straw or shredded leaves to retain moisture and suppress weeds.
During hot, dry spells, water more frequently—check soil moisture 2–3 inches down.

If the soil dries out completely, the cabbage may bolt (go to seed) instead of forming a big head.

Fertilize Regularly For Maximum Size

Giant cabbages are heavy feeders. They need a steady supply of nutrients throughout the growing season.

Two weeks after transplanting, apply a nitrogen-rich fertilizer (like fish emulsion or blood meal).
Repeat every 3–4 weeks until the head begins to form.
Switch to a balanced fertilizer (10-10-10) once the head starts swelling.
Side-dress with compost or aged manure halfway through the season.

Be careful not to over-fertilize with nitrogen late in the season. Too much nitrogen can cause loose, leafy heads instead of dense, heavy ones.

Control Pests And Diseases

Giant cabbages attract the same pests as regular cabbages, but damage is more costly. Common problems include:

Cabbage worms – Small green caterpillars that chew holes in leaves. Use row covers or spray with Bacillus thuringiensis (Bt).
Aphids – Tiny insects that suck sap. Blast them off with water or use insecticidal soap.
Slugs and snails – They eat leaves and can kill young plants. Use beer traps or diatomaceous earth.
Clubroot – A soil-borne disease that causes swollen roots. Rotate crops and avoid planting in infected soil.

Inspect your plants weekly. Early intervention saves your harvest.

Support The Growing Head

As the cabbage head expands, it becomes top-heavy. The stem may not support the weight, especially in wind or rain. Provide support to prevent the plant from tipping over.

Use a stake or tomato cage placed near the stem.
Loosely tie the stem to the support with soft garden twine.
Alternatively, mound soil around the base of the stem for extra stability.

Do not tie too tightly. The stem needs room to expand as the cabbage grows.

Harvest At The Peak Of Size

Giant cabbages can take 100–150 days from transplanting to harvest, depending on variety and weather. You want to harvest when the head is firm and dense, but before it splits.

Check the head by pressing gently. It should feel solid, not spongy.
If the head starts to crack or split, harvest immediately. Splitting ruins the cabbage for storage.
Cut the stem with a sharp knife, leaving a few outer leaves attached to protect the head.

Harvest in the morning when temperatures are cool. This helps the cabbage stay crisp and fresh.

Store Giant Cabbages Properly

Giant cabbages are too large for most refrigerators. Store them in a cool, humid place like a root cellar or basement.

Remove loose outer leaves.
Wrap the head in a damp cloth or newspaper.
Place in a plastic bag with small holes for ventilation.
Store at 32–40°F with 90–95% humidity.

Properly stored, a giant cabbage can last 3–4 months. Check regularly for rot or wilting.

Troubleshooting Common Problems

Even with careful planning, things can go wrong. Here are solutions to frequent issues:

Small heads – Usually caused by insufficient nutrients, water, or sunlight. Check your soil and adjust.
Bolting (going to seed) – Triggered by temperature swings or drought. Keep soil evenly moist and protect from extreme heat.
Yellow leaves – Often a sign of nitrogen deficiency. Apply a nitrogen-rich fertilizer.
Stunted growth – Could be root damage from transplanting or compacted soil. Loosen soil and avoid disturbing roots.

If you notice problems early, you can often correct them before the cabbage stops growing.

Tips For Competition-Grade Cabbages

If you want to enter a giant cabbage contest, follow these extra steps:

Start seeds in January or February for a summer harvest.
Use a soil test kit to fine-tune nutrient levels.
Water with a diluted liquid fertilizer every week during head formation.
Remove all but the strongest seedling per planting hole.
Thin side shoots and lower leaves to direct energy to the main head.

Competition growers often use specialized techniques like grafting or hormone treatments, but for most home gardeners, good basics are enough to produce a 30–50 pound cabbage.

Frequently Asked Questions

How long does it take to grow a giant cabbage?

Most giant cabbage varieties take 100–150 days from transplanting to harvest. Starting seeds indoors adds another 6–8 weeks, so plan for a total of 5–7 months from seed to harvest.

What is the best fertilizer for giant cabbage?

A balanced 10-10-10 fertilizer works well, but giant cabbages also benefit from compost tea, fish emulsion, and bone meal. Avoid high-nitrogen fertilizers late in the season.

Can I grow giant cabbage in a container?

It is possible but challenging. Use a container at least 20 gallons in size with excellent drainage. Giant cabbages need deep soil and frequent watering, so containers dry out quickly.

Why is my giant cabbage not forming a head?

Lack of head formation is often due to too much nitrogen, too little sunlight, or temperature stress. Ensure your plants get 6–8 hours of sun daily and avoid over-fertilizing with nitrogen.

How do I know when my giant cabbage is ready to harvest?

The head should feel firm and dense when pressed. It should also be fully round and have stopped expanding. If the head starts to crack, harvest immediately.

Growing a giant cabbage takes time, but the reward is impressive. With the right variety, rich soil, consistent care, and a little patience, you can produce a cabbage that turns heads. Start preparing your garden bed now, and by the end of the season, you might be holding a new personal record.