Bolting Plants: What Is It, and How to Deal with It

When someone bolts, it usually means that he or she is running or moving quickly from one place to another. But what does it mean when a plant bolts?

While a plant may not “run away” physically, their growth can run rapidly to flower and set seed in a very short period of time, prematurely producing flowering stem(s) before the plant is ready for harvest. The result of this bolting is usually inedible, bitter-tasting or poor quality crops.

Why Do Plants Bolt?

Bolting occurs when the season changes – most plants bolt when the weather heats up, although a few others may be triggered by low temperatures instead. As the day gets longer and warmer, plants may experience heat and water stress, and thus focus their energy on producing seeds before their time. This is especially likely for photo-sensitive plants such as lettuce and spinach.

In contrast, warm-season plants such as onions, beetroots and carrots may bolt in response to unstable weather, which confuses their life cycle. When the days get prematurely warm, these plants may take it as a sign that winter is over and start preparing for reproduction – but when the temperatures return to lower numbers it will inhibit healthy growth, resulting in dud produce.

How Can I Prevent Bolting?

  • Sow your plants regularly, especially if the weather fluctuates a lot. This will increase your chance of healthy growth.
  • Keep your soil healthy with careful watering or compost addition to encourage good growing conditions.
  • Sow cold-sensitive plants in early spring and cold-season plants in late summer to reduce risk of bolting.
  • Provide the best conditions for your plants. Providing shades for cool-season plants and placing your warm-season plants in full sun exposure are recommended.
  • Opt for bolt-resistant varieties, such as the Boltardy beetroot.