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Spring Cabbage · Brassica oleracea var. capitata

Why is my Spring Cabbage bolting instead of heading?

Bolting happens when your cabbage decides to send up a flower stalk instead of forming a tight head. This is almost always a reaction to heat stress or sudden temperature changes. Check your local weather patterns to see if a heat wave triggered this change.

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Check these first

  1. Observe if the center of the plant is stretching upward.
  2. Check the soil moisture to ensure it is not drying out.
  3. Monitor the daily temperatures in your garden.

Likely causes

  1. Heat stress

    Most likely

    How to tell: The center of the plant begins to stretch upward, forming a tall, thick stalk instead of a round head. The leaves may also start to taste bitter.

    What to do: Provide shade cloth during the hottest part of the day to keep the soil and plant cool. Ensure you are watering deeply every 3 to 7 days to keep the root zone consistently moist.

  2. Temperature fluctuations

    Possible

    How to tell: Plants exposed to a cold snap followed by a sudden warm spell often trigger a reproductive response. The plant thinks the season is ending and rushes to produce seeds.

    What to do: Use row covers to protect young plants from extreme temperature swings in early spring. Consistent moisture helps the plant stay focused on vegetative growth rather than flowering.

Other plants that won't flower

Find out what's wrong with your spring cabbage

The list above covers the usual causes. Pocket Botanist looks at a photo of your actual plant and tells you the likely cause, how serious it is, and what to try first. Identification and a health check are free.

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When to worry

Once the flower stalk begins to form, you cannot stop it. The plant will become bitter, so it is best to harvest it immediately or compost it.

Stopping it coming back

Plant your cabbage early enough so it matures before the heat of summer arrives. Choose varieties specifically bred to be bolt resistant.

Spring Cabbage: not flowering? Check yours with a photo

Every plant is a little different. Take a photo of your spring cabbage and Pocket Botanist tells you which cause is most likely, how serious it is, and what to try first. A few checks a day are free. Save the plant and you get care reminders timed for it.

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Questions people ask

Can I eat a cabbage that has started to bolt?
You can, but the leaves will likely be tough and bitter. It is usually better to harvest it as soon as you notice the stalk forming.
Does watering more prevent bolting?
Consistent watering helps reduce stress, which is a major factor in bolting. Keep the soil moist to give your plant the best chance of forming a head.

More problems with Spring Cabbage

Back to the Spring Cabbage guide

This article was generated with AI on from the plant’s care profile and is general information, not horticultural advice. Read about how we build these guides.