How do you grow broccoli in fall?
Written by
Paul Reynolds
Reviewed by
Prof. Samuel Fitzgerald, Ph.D.Fall broccoli yields more [flavor] and with fewer [bugs]! Plant your seeds indoors when the late summer days swelter away and the skies are sultry at 80°F (27°C) or higher. I always used the air conditioning room in my early growing days to obtain success. That takes them right into cool plant-out days with no fear of touchy bolting. Don't transplant them until the sweet breath of Fall night air gets in. In other words, wait until the hot spells are finally over and the days have settled into steady temperatures of less than 80°F (27°C).
Cold Zones (3-4)
- Start seeds indoors by early June
- Transplant seedlings before July 10
- Use cold frames for early frost protection
- Harvest before September hard freeze
Temperate Zones (5-6)
- Sow seeds mid to late August
- Transplant by September 1-15
- Apply heavy straw mulch in October
- Harvest after first light frosts
Warm Zones (7-10)
- Plant seeds September through October
- Transplant October-November
- Minimal frost protection required
- Harvest through winter months
Harden off your seedlings before moving them outdoors. Begin 7-10 days before you plan to move them. Each day, start with 2 hours of morning shade and increase their exposure over the next week to 10 days. I cover my plants with floating row covers to protect them initially from pests and temperature extremes while they are establishing.
Maximize cold advantages for flavor development: frost turns the starches to sugar in the heads of broccoli; therefore, I do not harvest until after the first hard frosts. The purple varieties develop a much deeper color in the cold. Try to harvest them while it is still chilly in the morning. They are then doubly sweet. Editors Note: Cold very much reduces the bitterness also.
Frost protection: use thick straw mulch. Once temperatures dip below 50°F, apply 4 to 6 inches of mulch around the base of the plants you wish to protect. When a frost is forecasted, install fabric covers. I secure my covers to metal hoops. On sunny days, be sure to ventilate them.
Select a cold-hardy variety, such as Purple Sprouting or Waltham 29. These two will tolerate temperatures to about 20°F (-7°C). I no longer grow any heat-sensitive plants for fall planting. Choose an appropriate variety, and you're guaranteed a hatful of big heads if given the time to mature, before deep freezes set in. Time the dates of maturity according to the information on the seed packet.
Adjust your watering according to the cooler temperatures. You don't want to water too much, or the roots may start to rot. I only water when the first 2 inches have dried out. Consider using drip irrigation to prevent the foliage from getting wet. Watering in the morning gives the plant time to absorb moisture before the cool night sets in. Your plants won't crack once the heads start to form.
Read the full article: When to Plant Broccoli for Best Results
