Brassica red/brown/yellow leaves - Ask Extension
My broccoli and cauliflower have been a slow go this spring/summer. I put them in back in early May. The leaves turn red, then brown, then yellow. ...
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Brassica red/brown/yellow leaves #873501
Asked June 17, 2024, 5:21 PM EDT
My broccoli and cauliflower have been a slow go this spring/summer. I put them in back in early May. The leaves turn red, then brown, then yellow. The broccoli buds are yellow. Very small. The cauliflower is doing some better. I've included some photos. As per advice on several gardening sites, I added fish emulsion and blood meal as they blamed the condition on lack of nitrogen. I'm in Waldport, right on the ocean.
Thank you for any advice.
Carolyn
Lincoln County Oregon
Expert Response
Thank you for your question.
The purplish leaves could be due to a variety of factors:
- Soil & air temperatures too cold
- Phosphorus deficiency in the soil or soil pH outside optimal 6.0-7.0 range which can hinder phosphorus uptake (you could add some bone meal)
- Not getting enough sun (requires 6-8 hours per day)
- Too much nitrogen & potassium fertilizer may also hinder phosphorus uptake
- Natural buildup of pigment anthocyanin due to excessive sun exposure, temperature fluctuations,
Here's an article that discusses anthocyanin in Brassica - https://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=41061#:~:text=The%20purple%20color%20is%20caused,also%20can%20cause%20loose%20heads.
The yellowish small broccoli buds could show that they are starting to bolt. This could be due to water stress (too much or too little), nutrient deficiency, too cold temperatures (less than 50) or too hot temperatures for too long a period, increased day length (more sunlight received).
Water regularly as needed. Consider using mulch that will help keep moisture in the soil and keep the roots cool. Fertilize with a balanced fertilizer.
You might also try using shade cloth or row covers to protect heads during the warmest periods of the day. You can also tie leaves up over the heads to provide shade and therefore reduce tendency to bolt.
The purplish leaves could be due to a variety of factors:
- Soil & air temperatures too cold
- Phosphorus deficiency in the soil or soil pH outside optimal 6.0-7.0 range which can hinder phosphorus uptake (you could add some bone meal)
- Not getting enough sun (requires 6-8 hours per day)
- Too much nitrogen & potassium fertilizer may also hinder phosphorus uptake
- Natural buildup of pigment anthocyanin due to excessive sun exposure, temperature fluctuations,
Here's an article that discusses anthocyanin in Brassica - https://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=41061#:~:text=The%20purple%20color%20is%20caused,also%20can%20cause%20loose%20heads.
The yellowish small broccoli buds could show that they are starting to bolt. This could be due to water stress (too much or too little), nutrient deficiency, too cold temperatures (less than 50) or too hot temperatures for too long a period, increased day length (more sunlight received).
Water regularly as needed. Consider using mulch that will help keep moisture in the soil and keep the roots cool. Fertilize with a balanced fertilizer.
You might also try using shade cloth or row covers to protect heads during the warmest periods of the day. You can also tie leaves up over the heads to provide shade and therefore reduce tendency to bolt.
