Brown Bud

You’ve probably seen it in your garden. Instead of developing a tightly packed head of green florets, your broccoli looks a little loose and floppy. Then, the florets turn brown. This die-off of unopened flowers is called brown bud or brown bead.

As a farmer, brown bud can make a crop unsellable, devastating a family’s financial situation. As a home gardener, things aren't nearly so dire. Now, we are not talking about the tiny black and brown fungal spots that occur on broccoli stored too long. You can cut those spots out and eat the rest, but that particular broccoli is probably past its prime. Brown bud is not a disease. Instead, it is a physiological disorder.

Symptoms of brown bud

Unlike your standard grocery store variety of broccoli, with its tightly packed head of unopened flower buds, heads affected with brown bud have a loose arrangement. The unopened florets at the center of the head first turn yellow (chlorotic) and then brown. This browning can spread across the head. These dead florets break off, providing easy access for pathogens.

Causes of brown bud

This poorly understood condition most frequently occurs when temperatures are higher than is ideal for this cool-weather crop. Heavy clay soil is another contributing factor. 

Brown bud is more likely to occur when nitrogen is deficient and during periods of low relative humidity. Some believe insufficient calcium causes brown bud, but research does not support those claims.
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Controlling brown bud

If brown bud has been a problem for you in the past, try starting your broccoli when temperatures are lower and the weather is wetter. And provide plenty of nitrogen since fast-growing heads are less likely to develop brown bud. Regular irrigation can also help prevent this disorder. Some cultivars, such as ‘Skiff’, are more likely to develop brown bud. While others, such as ‘Coaster’ and ‘Shotgun’, are less likely.

To avoid brown bud in your garden, feed those heads plenty of water and nitrogen!