Possible Reasons Why Cabbage Won't Form A Head

Cabbage Plant With No Head
cabbage no head
(Image credit: arfo)

Cabbage is a cool season crop that you can grow twice in a year. Some varieties of cabbage, such as Savoy, will take up to 88 days to form heads. If you're wondering when will cabbage make a head, you may simply need to wait longer or your plants may be stressed by improper culture or temperatures. When a cabbage does not form a head, this condition is called blindness and can arise for many reasons.

When Will Cabbage Make a Head?

The answer to, “When will cabbage make a head?” is, it depends. The common green cabbages form heads more quickly than the huge Savoy cabbage. You can expect to see heads in approximately 71 days with green cabbage. Red cabbage takes slightly longer and Nappa cabbage will form small heads in only 57 days. Cabbage head formation sometimes occurs better in the moist, gently warming conditions of spring than in the cooling days of fall. Consult the seed packet for days from seed to harvest and be patient.

Why Cabbage Won't Form

There are a few cultural and temperature elements that may be the reason for cabbage not growing a head.

  • Excess nitrogen may cause the plant to form more leaves that are loosely held and do not make a head.
  • Early damage by cutworms may prevent the plant from heading.
  • Club rot in soggy alkaline soils is another reason why cabbage won't form a head.
  • Poor cultivation or planting the seedlings when temperatures are 80 degrees F. (27 C.) or more will also affect cabbage head formation.

How Do I Get Cabbage to Head Up?

Setting out the plants at the right time is crucial to cabbage head formation. Cabbage will bolt or send out flowers to set seed if they're exposed to temperatures below 45 degrees F. (7 C.). You'll also find cabbage not growing a head if they are exposed to extremely hot temperatures. An even temperature of 55 to 65 degrees F. (13-18 C.) favors the best cabbage production. Grow plants so they'll reach harvest well before the crushing heat of summer or prior to freezing fall temperatures. Fertilizing your cabbage with phosphorus will spur root formation and aid in the growth of the head. Use an 8-32-16 fertilizer to provide minimum amounts of nitrogen and potassium with a power punch of phosphorus. Water is crucial to head development in cabbage. If you're asking yourself, "How do I get cabbage to head up?” the answer may simply be water.

Bonnie L. Grant
Writer

Bonnie Grant is a professional landscaper with a Certification in Urban Gardening. She has been gardening and writing for 15 years. A former professional chef, she has a passion for edible landscaping.