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How Tall Does Broccoli Grow?

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A hardy, cool-season vegetable, broccoli is full of vitamins A and D. Traditionally, broccoli was grown as a spring and a fall crop. The development of new heat-tolerant varieties, however, means that broccoli is enjoyed in summer, too. Broccoli plant size affects spacing, and helps a grower identify when the plant is ready for harvest.


Broccoli plants grow upward, rather than out. At maturity, these plants grow up to 2 1/2 feet tall. To ensure broccoli plants have enough room to grow, leave 12 inches between plants in all directions.

Head Size

Broccoli plant head size varies by variety grown, growing condition, season and care. When plants are ready to harvest, broccoli heads range from 4 to 6 inches in width, or greater. The main or central heads are largest; smaller or late-developing side shoots are often only 1 to 2 inches across. Central heads weigh up to 1 lb., with smaller side shoots weighing no more than 1/3 lb.

Growing Condition

Broccoli plants appear yellow and exhibit poor growth if not given the right care from the start. Planting too late or too early in the year contributes to small plant size. Seedlings that were mistreated develop poorly, so purchase quality plants from a grower you trust. Fertilizing broccoli at planting time helps get plants off to a good start, but won't be enough to get poor quality plants to reach maximum growth.


In general, broccoli plants take around two months to mature. The plants are to be harvested before flowers develop, and are generally harvested for several weeks. Cutting the main heads first spurs growth of side shoots, which are picked later. When cutting broccoli heads from the plant, cut 5 to 6 inches of stem along with the head.

Grow & Harvest Broccoli Rabe

Choose a planting site that receives full sun and has well-draining soil. Apply a layer of 8-8-8 fertilizer to the planting site. Space the seeds one to three inches apart. If you want to plant more than one row of broccoli rabe, space the rows 18 to 24 inches apart. Water the broccoli rabe seeds well immediately after planting. Watering pushes the seeds into the soil so they are able to germinate. Thin the broccoli rabe seedlings to three to six inches apart. Pull weeds as soon as you notice them to prevent the weeds from stealing moisture and nutrients from the roots of your broccoli rabe plants. The stem, shoots and leaves are all edible.

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