Broccoli Growth Stages: A Week-by-Week Guide From Seed to Harvest
Broccoli is a dependable cool season crop that rewards careful timing. When you understand the broccoli growth stages, you can plan watering, feeding, and harvest with confidence. From seedling to full head, each step in the broccoli growth cycle follows a predictable pattern.
This week-by-week guide explains the stages of broccoli growing so you know what healthy development looks like and when broccoli is ready to harvest.
If you are choosing seeds, explore our full collection of broccoli seeds to compare maturity dates and head size.
Week 0–2: Germination and Broccoli Seedling Stages
Most gardeners start seeds indoors 4 to 6 weeks before the last frost for spring planting, or in midsummer for fall crops. When you start seeds indoors, sow broccoli seeds ¼ inch deep in moist seed mix.
Seeds usually sprout within 5 to 10 days at soil temperatures between 60°F and 75°F. These early stage growth stages of broccoli include:
- Two rounded seed leaves
- The first true leaves forming at the center
During these broccoli seedling stages, provide bright light and even moisture. Weak, leggy seedlings struggle later in the broccoli plant growth stages.
Week 3–5: Transplanting and Vegetative Growth
Once seedlings have 4 to 6 true leaves and sturdy stems, harden them off and transplant outdoors. Space plants broccoli about 18 inches apart to allow airflow and room for head formation.
This phase of broccoli plant growth focuses on building strong leaves. The plant is storing energy for future broccoli heads. Rich, well-drained soil and steady watering are critical during this period of plant growing.
For a deeper overview of soil preparation and timing, review our full guide on how to grow broccoli. You can also see practical techniques in our short video on growing broccoli.
Week 6–9: Head Formation Begins
In the next set of growing stages of broccoli, the plant shifts from leaf production to head development. A tight cluster of immature flower buds forms in the center.
This is one of the most important broccoli stages. The developing head of broccoli should appear compact and firm. Healthy plants show thick stems and deep green leaves.
Cooler temperatures between 55°F and 75°F produce the best heads. If temperatures rise too high, the broccoli growth time may shorten and heads may loosen.
Depending on the variety, early types may begin forming heads around 55 to 65 days after transplanting.
Week 9–12: Harvest Stage and Side Shoots
Most standard varieties mature in 60 to 80 days after transplant, depending on the variety.
Broccoli is ready to harvest when:
- The central head is firm
- The flower buds are tight
- No yellow flower petals are visible
If left too long, broccoli flowering stages begin. The buds open into small yellow flower clusters. Once flowering stage starts, texture becomes coarse and flavor declines.
Cut the main head with 5 to 6 inches of stem. Many broccoli varieties then produce side shoots along the stem. These smaller heads extend the harvest window for several weeks.
A broccoli growth time lapse would show steady leaf expansion followed by rapid bud development in the center. Understanding these broccoli stages of growth helps you harvest at peak quality.
Broccoli Varieties and Their Growth Patterns
Different broccoli varieties move through the growth stages of broccoli at slightly different speeds.
Strong performers include:
- Calabrese Broccoli Seeds (Organic): Classic large green heads with reliable side shoots.
- Di Cicco Broccoli Seeds (Organic): Early maturing and especially productive side shoots.
- Romanesco Broccoli Seeds (Organic): Distinctive spiraled heads with mild flavor.
- Rudolph Broccoli Seeds: Well suited for fall planting and cooler temperatures.
- Kailaan and Early Jade Gai Lan: Chinese broccoli types harvested mainly for stems and leaves rather than large central heads.
- All Season Broccoli Blend Seed Mix: Offers staggered maturity for extended harvest.
For seasonal planning ideas, see our article on Red, White and Broccoli, which explains how different types fit into cool weather rotations.
The Gift Seed Tin – Frost Kissed Collection also includes Calabrese Broccoli along with other cool season crops for diversified planting.
Summary of Broccoli Plant Stages
To simplify the stages of a broccoli plant:
- Germination
- Seedling leaf development
- Vegetative leaf growth
- Central head formation
- Harvest of green heads
- Side shoot production
- Flowering stage if not harvested
Recognizing each stage of broccoli plant growth allows you to adjust care. Avoid heavy nitrogen feeding once heads begin forming, and keep watering consistent to prevent stress.
Conclusion
Broccoli growing succeeds when you match the plant’s natural rhythm with cool weather and steady soil moisture. By understanding broccoli growth stages, you know when to expect leaf development, head formation, and harvest.
Watch for tight green heads, harvest before any yellow flower appears, and encourage side shoots for continued production. With proper spacing at 18 inches and careful timing, most varieties reward gardeners with abundant, flavorful harvests.
