Knowledge from Olle Garden Bed: Why Your Broccoli Heads Become Loose and Bitter

By regularly watering and maintaining stable, cool temperatures, broccoli can be a sweet, tight, and well-formed head. Read here are some things that you should know when It comes to Olle Garden Beds!

Key Points

Harvest broccoli when the central portion is green and tightly packed to avoid bitterness. Harvest in the morning for maximum moisture and sweetness.

Plant broccoli as an early spring or late summer crop to avoid high temperatures and enhance flavor.

Broccoli is one of the many vegetables in the Brassicaceae family, alongside other species like kale, cabbage, and cauliflower. It's a classic cool-season vegetable, capable of continuing to produce even when temperatures hover around freezing. While broccoli has its advantages, dealing with loose heads and bitterness in broccoli is not uncommon. Protecting broccoli from extreme water and temperature fluctuations and harvesting regularly can make a difference between a successful broccoli harvest and disappointing outcomes.


Harvesting Too Late

Broccoli matures relatively quickly. Depending on the variety, broccoli can be ready for harvest in less than two months after sowing. Broccoli should be harvested when the central head is still green and tightly packed. Once the center becomes loose and turns yellow, the plant is preparing to flower, and the taste becomes more bitter. Like most vegetables, it's best to harvest broccoli in the cool of the morning. Plants take up moisture during the night and convert some of the starch into sugars, so vegetables should be well-hydrated and sweet in the morning. To harvest broccoli, simply cut the stem about 6 inches below the head. The plant will continue to produce smaller heads from the side shoots that are forming. Check and harvest broccoli regularly to ensure it's always harvested at its best. Don't wait until the buds open to harvest broccoli, as once broccoli starts to flower or bolt, its taste becomes increasingly bitter and unpleasant. Bolted plants have reached the end of the season, so you should remove broccoli that begins to flower to make space for other things in your garden.

High Temperatures

Broccoli is a cool-season crop, and high temperatures and prolonged daytime heat can increase bitterness. For this reason, it's best to either plant broccoli as an early spring crop or wait to plant it in late summer so it can prepare for the fall. Broccoli planted in the fall typically performs better and tastes better than spring-planted broccoli because in many areas, spring temperatures rise too quickly, causing broccoli to bolt before it can thrive. A long and cool fall gives broccoli the time it needs to develop without the stress of high temperatures, resulting in a better harvest.

Irregular Watering

As a cool-season crop, broccoli requires extra care and attention when temperatures start heating up. Ensure broccoli is getting enough water. While insufficient watering can be an issue, excessive watering can also cause loose heads. 1 to 1½ inches of water a week, whether it's from rain or irrigation, is generally sufficient for broccoli during the growing season. Using mulch will help keep the broccoli's soil moist and cool. This is especially essential as broccoli has shallow roots that can be vulnerable to sudden changes in temperature or moisture.

Excess Nitrogen

While nitrogen fertilizer can lead to rapid growth and lush foliage, it's not always conducive to the ideal flavor and texture of vegetables. In broccoli, excess nitrogen can result in loose and fragile broccoli heads, as they grow too quickly in the late stages of development. Like most Brassicaceae family plants, broccoli is considered a heavy feeder, so heavy nitrogen fertilization in the early stages of growth is beneficial. However, it's best to gradually reduce or entirely stop nitrogen fertilization in the last four weeks before harvest to slow down the development of nearing maturity broccoli heads, making them tighter.

Improper Storage or Prolonging

Broccoli is at its best in flavor and least bitter when consumed shortly after harvest. It becomes less sweet and the bitterness becomes more pronounced the longer it's stored. When storing broccoli is necessary, it's best to ensure it's kept between 32°F and 39°F (0°C to 4°C), stored in a bag that allows for good airflow. If broccoli is left in the fridge for more than five days, its taste and texture deteriorate rapidly, so plan how you'll use this bounty of broccoli. If you can't use broccoli within a few days of harvest, it's best to blanch and freeze it for later use.

Perfect Broccoli Is Possible

Broccoli can be a delicious and nutritious homegrown vegetable. Bitterness in broccoli is often associated with allowing it to be subjected to extreme temperature and water fluctuations and waiting too long to harvest broccoli heads. Then, through proper storage and preservation, your broccoli can go from your garden to your table at its peak of freshness. Be sure to share this broccoli troubleshooting guide with friends and family battling this beloved Brassicaceae family plant.