Broccoli is a  COOL WEATHER plant, and grows best when temperatures are between 25° and 75° F.^a It does well in the spring and fall, but not during the hot summer.

Spring planting dates

For a spring planting, start indoors from seed 12 weeks before the last spring frost date. When the plants have 4-6 true leaves, harden them off , and transplant outside.^a This will be about 4-6 weeks before the last frost date.^b It is a hardy vegetable, and can tolerate frost, but it will bolt quickly if the weather gets too hot.

If you live in a mild climate (with a long spring and summers that don’t get very hot), it’s possible to plant seeds directly in the garden 2-3 weeks before the frost date.

Fall planting dates

To grow in the fall, start seeds indoors 14 weeks before the first fall frost date, and transplant them into the garden when they have at least 2-4 true leaves, usually about 9 weeks before the frost date. The plants will mature more slowly in the fall because the days are shorter, but since they can tolerate freezing temperatures, you can continue harvesting after the first fall frost.

If you live in a mild climate with a late or no fall frost date (after Nov 1), you might be able to plant broccoli from seed, and even grow it all during the winter!

If you live in a climate with hot summers and/or a short fall, choose varieties that mature quickly.

SFG Spacing

In the All New Square Foot Gardening book, Bartholemew recommends 1 per square. I have found that my broccoli gets really crowded with this spacing. Instead, I give each plant 18″, which is the same as planting 4 plants in 9 squares.

Fertilizing

Before planting, add lots of good compost to these squares, and possibly some all purpose (10-10-10) fertilizer. Broccoli loves thrives if it has plenty of nitrogen, so fertilize again 4 weeks after transplanting, when heads are 1 1/2″ in diameter, and after harvesting the main head.^a

Harvesting

Harvest before the flower buds open, when the buds are still tight. Cut off the head with 4-5 inches of stem. You’re better off harvesting a little too early than a little too late–flowers can appear overnight! The head may be small, so don’t expect grocery-store-sized broccoli. After the first harvest, don’t pull the plant out! Side-shoots will appear and produce several smaller heads.

My experience is that, here in the Mountain West, the broccoli yield is not as large and plentiful as it would be in cooler climates–but the flavor is UNBELIEVABLE! Definitely worth growing!

A Note About Timing

Many seed packets indicate that broccoli takes from 55 to 75 days to harvest. Generally, this means from TRANSPLANT to harvest, not from seed to harvest. It takes an additional 4-6 weeks to grow broccoli from seed to transplant.

More Broccoli Resources

• Broccoli Reference Sheet (Utah Extension Service)
• Growing Broccoli in the Fall

Happy gardening!

Sources:
a. Broccoli in the Garden, Dan Drost and Michael Johnson,
USU Extension, February 2007.
b. All New Square Foot Gardening, Mel Bartholemew,
Cool Springs Press, 2005.

Filed under: Veggies