Plant Bolting: A Definition

What Happens When a Plant Bolts?

mercurial. fickle. ever-changing. (273/365)
ejchang/Flickr/CC BY-SA 2.0

As a gardener, it is helpful to learn popular phrases that go along with the activity. Knowing what your plants are doing--and what those things are called--is also helpful in the event that you seek out gardening help. Take plant bolting, for example. Bolting is defined as growing a tall flower stalk in a very short period of time. When you observe this, you can better tend to the garden.

Why Plants Bolt

What happens when a plant bolts? Essentially, it is the premature production of a flowering stem (or stems) on a plant before it can be harvested. Bolting is the plant's natural attempt to produce seeds so it can reproduce. It occurs when the weather heats up.

To produce a bolted stem, a plant typically redirects resources from producing leaves, roots or other edible parts. The extensions are its leaf-bearing parts. When a plant bolts, it is often a sign that you're in for a poor harvest. It also is an indication that it will decline in terms of flavor. 

Hot weather isn't the only thing that can cause veggies to bolt. Changes in the length of the day and stressors such as not getting enough water or minerals can cause bolting. And yes, low temperatures at certain growing stages can trigger a plant to bolt. Plants that are stress may respond to that stress by bolting so that they can produce seeds before they die.You know, to perpetuate their species and all.

Bolting is also known as going to seed. The term bolting is typically used with regard to vegetable gardening. Crops inclined to bolt include lettuce, basil, leeks, carrots, cabbage, turnip, arugula, beetroot, brassicas, spinach, celery, and onion.

Prevent Bolting

There are a few things you can do to prevent vegetables from bolting. Here are a few ways to prevent bolting: 

  1. Try to avoid plant stress. If the soil is too dry or the compost is not nutritious enough, give it more water or fresh soil or compost. Cover plants in the event of a cold spell, which can keep them from being directly exposed to cold temperatures, rain or snow. 
  2. Choose varieties of the plant that can resist bolting. For example, you may not experience bolting with Boltardy beets.
  3. Change your growing season. Lettuces, cabbage and arugula are not known to do well when sown in the spring. In that case, save your lettuce-growing for the summer. 
  4. Pick the outer leaves off, keeping them from maturing. This can extend the time the plant produces by as much as 10 weeks, giving you more of a chance to grow it better. 
  5. Sow plants regularly. Sowing plants at different intervals can give you more of a chance of producing at least some that do not bolt.