Why Are My Vegetables Flowering?

Table of Contents:

Why Do Plants Flower?
Is Bolting the Same as Flowering?
1. What Is Bolting?
2. What Is Flowering?
What Causes Plants to Flower Prematurely?

So you grew some vegetables, but now they're flowering and you don't know why. Let's talk about it...

yellow flowers purple stems broccoli bolted — Purple broccoli has some incredibly radiant blooms!

Why Do Plants Flower?

In the flowering stage, angiosperm (flowering plants) utilize their flowers for sexual reproduction.

When flowers are pollinated (by wind, insects, animals, or water), plants can then reproduce by developing seeds that carry on their genes.

Is Bolting the Same as Flowering?

You'll often see the phrase "bolt to flower" which might make it seem like these two terms are identical.

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While often used interchangeably, these two terms do not quite mean the same thing.

brassicas flowering radish and broccoli among swiss chard in garden — Daikon and kohlrabi seen flowering due to hot temperatures seen here in the desert in late-spring

What Is Bolting?

Bolting generally refers to the transition period where the plant goes from the vegetative stage to the flowering stage. Bolting is the liminality between these two.

During bolting, many plants go through a process of flower stalk elongation in order to raise the future flowers up higher for pollinators to find.

Think lettuce, whose typical low growth habit completely transforms with the growth of a 2-3ft high woody flower stalk (inflorescence) which the leaves begin to spiral up.

Leaves can often get much thicker, tougher, and more bitter during this phase to protect themselves from predation long enough that they can make it through flowering and reproducing.

purple mustard flowering yellow flowers brassica — Purple mustard looks spectactular when flowering, but the leaves become very tough, bitter, and unpalatable in the process.

Bolting also has an addition connotation sometimes, which is that the plant is transitioning towards flowering prematurely.

This connotation does not always appear to be attached to this phrase, but it is sometimes.

In this case, bolting would mean both transitioning from vegetative to flowering stage and doing so because of adverse environmental conditions before it otherwise would have.

In some uses, the word may also mean transitioning from vegetative to flowering stage and doing it before I got to finish harvesting the leaves I wanted.

Be aware of these contexts, as this word 'bolting' is a slippery one that's only loosely-defined. People use it to mean different things so you may have to ask for clarification when it's used.

What Is Flowering?

Flowering is the reproductive stage that comes after the bolting transition zone, as they move away from the vegetative stage.

In the flowering stage, plants are pollinated and then reproduce via seeds.

yellow flowers on collard greens — Collard greens bolting to flower in the heat

What Causes Plants to Flower Prematurely?

The short answer is stress. The cause of any plant bolting and going to flower before it normally would in its lifecycle is always stress.

Stress in plants causes hormones to change, typically producing more to the flower-inducing hormone gibberellins. If you're familiar with selective plant breeding you may recognize that as the hormone you apply to force your plant to induce flowering.

It's not enough to simply say that 'stress' is the root issue, however, as any number of factors could be underlying that stress. If you hope to understand why your plant is flowering early, you'll need to understand what exactly the stressor is that triggered it.

Common stressors in plants that trigger early bolting include: