What Does Bolting Mean in Gardening?

When you’re gardening, it’s important to know the meanings of different terms. Bolting is one term that you may have heard before, but may not know what it means. Bolting is a process that some plants go through in order to reproduce. They send up a flower stalk in order to release their pollen and fertilize other plants. If you see your plants going into bolt mode, don’t worry – there are ways to stop them!

When a plant prematurely develops flower stalks and seeds, preventing the plant from producing a strong harvest, it is said to be bolting.

Bolting, sometimes known as “going to seed”, is the process of concentrating a plant’s energy on producing seeds and a blossoming stem rather than leaves and roots.

Bolting always signals the end of new leaf development in perennial plants. It’s an indication that the plant will soon die in annual plants [1] .

In this blog post, we will discuss what bolting is and how to prevent it from happening in your garden.

What Is Bolting?

In the gardening world, though, this phrase has a more figurative meaning. It’s all about growth running away from you. When a plant’s growth shifts from being mostly leaf-based to being mostly flower and seed-based, it is said to bolt.

What Is Bolting?

This is usually an issue with annuals, which only live for one growing season. The plant’s goal is to produce as many seeds as possible before winter comes, and it will sacrifice leaves and stems to do so. This can be a problem if you were hoping to eat the leaves or use them in some other way.

Bolting can also happen when a plant gets too hot or too cold. If the temperatures dip suddenly, a plant may try to flower quickly before it dries, resulting in bolting. The same thing can happen if the weather warms up unexpectedly early in the spring [2] .

How to Identify Bolting?

The good news is that finding and treating ingress is straightforward. The bad news is that, because it’s so easy to detect, most homeowners are unaware of it until their plants start dying.

When you find evidence of bolting on a plant [3] :

  • You see a slender stalk with just a few leaves appear out of the plant’s foliage, which is studded with numerous small leaves;
  • This stalk develops buds, which become flowers before seeds;
  • You can tell that the remainder of the plant’s growth has come to a halt;
  • You notice that the leaves’ flavor is getting increasingly harsh;
  • The plant flowers and sets seed much earlier than normal;

Additionally, the leaves’ flavor will become increasingly harsh as the plant bolts. Finally, the plant will flower and set seed much earlier than normal. If you see any of these signs on your plants, they are likely bolting.

Why Bolting Is Bad?

Bolting is when a plant grows too quickly and produces flowers or seeds before the leaves have fully developed. This can happen for a number of reasons, including stress, lack of nutrients, or changes in temperature. Bolting reduces the plant’s ability to photosynthesize and produce food, which can make it weak and less productive. In some cases, bolting can also cause the plant to produce fewer fruits or vegetables.

But there’s more to it than that. When a leafy vegetable bolts, it no longer creates those beautiful big, delicious leaves for which you nurtured it. The leaves on the final three or four branches will be less numerous and tougher. Any further leaves developed would have similar tastes, so you’ll avoid eating them.

Why Bolting Is Bad?

Finally, if an annual plant produces a seed, it will die since its purpose in life has been completed.

Causes of Bolting in Plants [4] :

  1. The day length increases. Planting too late in the spring leads to excessive plant bolting as a result of longer days. The days, on the other hand, become longer during summer, exposing plants to greater sun exposure and potentially harming them. If you sow your seeds too early in the spring, this may be an issue for you;
  2. Root stress. Root strain happens when a plant’s root system is disrupted by transplanting or if it runs out of space in a container that isn’t big enough.  This can also occur if the roots are damaged by pests or diseases. When a plant’s root system is stressed, it can cause the plant to bolt in an attempt to reproduce before it dies;
  3. Hot weather. Plants that are exposed to hot temperatures may bolt as a way to try and escape the heat stress. This is especially true for plants that are grown in areas with high summer temperatures.
    If you live in an area with hot summers, you may need to take steps to protect your plants from the heat, such as shading them during the hottest part of the day or planting them in a location that gets some relief from the afternoon sun.
  4. The top layer of the ground is extremely hot. The days grow longer as summer approaches, and the temperature rises. Crops become stressed as the soil temperatures rise, prompting them to begin seed and flower formation. Bolting frequently happens when there’s an excessively hot spring or you plant crops too late in the season, despite the fact that this isn’t a problem when it occurs on schedule at the end of the plant’s life cycle;
  5. Drought conditions. When a plant doesn’t get enough water, it will go into survival mode and try to reproduce before it dies. This is especially true for annual plants that only live for one growing season. If you’re experiencing drought conditions, you’ll need to water your plants more frequently to prevent them from bolting;
  6. Fertilizer burn. Over-fertilizing can cause a condition called fertilizer burn, which can stress plants and cause them to bolt. Fertilizer burn usually happens when too much nitrogen is applied to the soil or when the fertilizer is applied too close to the plant’s roots;
  7. Inadequate drainage. Plants that are grown in areas with poor drainage may also be susceptible to bolting because they’re constantly stressed by wet conditions. If you live in an area with poor drainage, you’ll need to take steps to improve the drainage in your garden or choose plants that are tolerant of wet conditions;

Can You Eat a Plant After it Bolts?

If you’re growing your own vegetables, you may be wondering if it’s safe to eat a plant after it bolts. The answer is yes! Bolting simply means that the plant has gone to seed, which can make the flavor of the vegetable less desirable. However, the vegetable is still safe to eat [5] .

Can You Eat a Plant After it Bolts?

However, after a plant has bolted, it is generally inedible. Because all of the plant’s energy goes into producing seeds, the rest of the plant tends to get hard and woody as well as flavorless or even poisonous. Occasionally, if you spot a plant in the early stages of bolting, you may temporarily stop the process by cutting off the flowers and flower buds. In some plants, such as basil, the plant will resume growing leaves and will not bolt again.

Broccoli and lettuce are two prominent examples of plants that benefit from this approach because it allows for additional time to harvest before the crop becomes inedible.

Plants That Bolt and When

Annual Vegetables

These include plants in the cabbage family, such as broccoli, cauliflower, and Brussels sprouts. They also include beets, spinach, and lettuce. Most annual vegetables will bolt in warm weather.

The life cycle of these vegetables takes place in a single growing season. They may be prone to bolting when the weather warms up in late spring/early summer [6] .

Annual vegetables typically bolt in warm weather. The life cycle of these vegetables takes place in a single growing season, so they may be prone to bolting when the weather warms up in late spring or early summer.

Biennial Vegetables

Annuals are also known as biennials since their lives span two growing seasons. In the first year, they develop a vegetative component, and in the second year, they blossom and produce seeds.

Biennials that bolt includes members of the cabbage family, such as kale and collards. They also include carrots, parsley, and turnips.

It’s important to harvest annual vegetables before they bolt.

Once they flower and produce seeds, the leaves will become bitter.
Biennial vegetables can be harvested in either the first or second year.

If you want to eat the root vegetable, then you should harvest it in the first year. If you want to eat the leafy green, then you should wait until the second year.

Ways to Prevent Your Plants From Bolting

Plant bolt-resistant seeds

Seek for seeds labeled “bolt-resistant” or “slow bolting”, as they have been created to endure circumstances that induce bolting. Look for heat-treated onion sets, for example, when growing onions; these bulbs can withstand high temperatures and are far less prone to produce flower buds in the summertime [7] .

Introduce Shade

When temperatures begin to rise, attempt to introduce some shade to your plants. This can be done by putting up a temporary canopy or simply moving the pots to a shadier location. Be careful not to put the plants in too much shade, however, as this can also lead to problems such as stunted growth.

Mulch is a wonderful way to keep your soil cool

Mulching is an excellent way to not only keep your soil cool but also to help retain moisture and suppress weeds. You can use a variety of materials for mulch, such as wood chips, straw, or even shredded newspaper. Be sure to reapply the mulch every few weeks as it will eventually break down.

Plant your produce in the fall or winter, when the weather is cooler

Early spring planting is not recommended during the summer months, when temperatures may be excessively high. If you live in a warm environment, try growing spring veggies in the fall instead, when unusually hot weather is less likely.

Spring or fall plantings are possible for Brussels sprouts, cabbage, and bok choy (Brassicas).

Use the correct fertilizer, regardless of what kind it is

If you fertilize your plants, be careful that it isn’t a fertilizer designed for leaves and stems rather than flowers.

Use the correct fertilizer, regardless of what kind it is

Nitrogen is a common component in fertilizers that encourage green growth.

Plant your seeds as soon as possible after the last frost

Direct sowing carrots, turnips, beetroot, radishes, and other plants that are sensitive to root strain stress outside rather than transplanting them promotes optimum growth. This allows their root systems to develop uninterruptedly.


FAQ

What does bolting look like?

Bolting is the process where a plant produces flowers and then sets seeds. The plant grows rapidly, often reaching its maximum height in just a few weeks. Once the plant has flowered and set seed, it dies back. This is why you’ll often see plants that have bolted (flowered and gone to seed) in your garden before they’ve reached their full size or potential [8] .

Is bolting the same as flowering?

No, bolting and flowering are not the same. Bolting is when a plant grows too quickly and produces seeds before the leaves have fully developed. This usually happens in response to warm weather or long days.

Flowering is when a plant produces flowers. Bolting can happen to leafy greens, such as spinach and lettuce, as well as root crops like beets and radishes.

When a plant bolts, it becomes tough and bitter-tasting. The best way to prevent bolting is to sow seeds at the right time of year for your climate and to keep plants well-watered so they don’t experience stress.

Is bolting good for plants?

Bolting is not generally considered to be good for plants. When a plant bolts, it produces flowers and seeds very quickly in an effort to reproduce before dying. This usually happens when the plant is stressed or doesn’t have enough energy to produce fruits or vegetables. Bolted plants often have fewer nutrients and are less flavorful than non-bolted plants.

What can you do with bolted greens?

Allow your bolting lettuce or other leafy greens to bloom and develop seeds rather than pulling them out. The blooms attract pollinators, so you may gather the seeds and store them for next season’s crop [9] .

How do you eat bolted broccoli?

Broccoli does not recover from a small start. It’s still edible (if you like the buds that size), so you could still salvage some, but it’s better to remove the plants now and plant something different [10] .

How do you keep Swiss chard from bolting?

The best way to keep Swiss chard from bolting is to plant it in the spring and harvest it regularly. Swiss chard is a cool-weather crop, so it will bolt (flower and produce seed) if the weather gets too hot. Bolting can also be caused by stress, so make sure to water your plants regularly and fertilize them if needed.

How do you keep Swiss chard from bolting?

If you do see Swiss chard starting to bolt, you can still eat the leaves, but they will be bitter. You can also try cutting off the flower stalk to see if that delays bolting.

Can you eat bolted carrots?

It is not a smart idea to consume carrots that have bolted. The carrot will become very fibrous and hard after it bolts, making it un-edible. If you are growing carrots for their greens, then you can still harvest them after the plant bolts. The leaves of the carrot will become bitter, but they can be used in salads or as a cooked green [11] .


Useful Video: What Does it Mean When a Plant Bolts?


References:

  1. https://www.masterclass.com/articles/ways-to-prevent-vegetables-from-bolting#what-is-bolting
  2. https://www.gardeningknowhow.com/edible/vegetables/vgen/what-is-bolting-what-it-means-when-a-plant-bolts.htm
  3. https://www.thespruce.com/why-do-plants-bolt-2539753
  4. https://www.masterclass.com/articles/ways-to-prevent-vegetables-from-bolting#3-causes-of-bolting-in-plants
  5. https://www.gardeningknowhow.com/edible/vegetables/vgen/what-is-bolting-what-it-means-when-a-plant-bolts.htm
  6. https://bustlingnest.com/guide-to-plant-bolting/
  7. https://www.masterclass.com/articles/ways-to-prevent-vegetables-from-bolting
  8. https://www.towergarden.com/blog.read.html/en/2015/7/bolting_basics_how.html
  9. https://www.birdsandblooms.com/gardening/fruit-and-vegetable-gardening/vegetable-garden-leafy-greens-bolt/
  10. https://gardening.stackexchange.com/questions/17579/can-i-save-this-crop-of-broccoli-that-bolted-early
  11. https://gardeniaorganic.com/can-you-eat-bolted-carrots