How To Stop Broccoli From Bolting: Complete Guide

One of the many reasons to start a garden is for the ability to have fresh produce in your own backyard. Broccoli is a nutrient-dense green making it a favorite in the gardening community. It is also fairly simple to grow as long as you take the steps necessary to prevent it from bolting. 

Here’s how to stop broccoli from bolting:

  1. Plant in the spring or early fall.
  2. Plant in the shade or create some.
  3. Water your broccoli deeply and regularly.
  4. Create healthy soil for your broccoli to grow in.
  5. Apply mulch to protect the plant’s roots. 
  6. Don’t over-fertilize the soil.
  7. Plant broccoli types that bolt less easily. 
  8. Reduce stress on the plant. 

In the rest of this article, we will take a look at the steps you can take to prevent your broccoli from bolting too early and ruining your supply of fresh broccoli. 

1. Plant in the Spring or Early fall

When it comes to preventing your plants from bolting too early, it is essential to ensure that you are planting them during the right season. This is especially true of plants like broccoli, cauliflower, lettuce, and spinach. 

Broccoli should be planted in the spring or early fall and does incredibly well with temperatures as low as 40 °F (4.4 °C). However, broccoli plants are highly susceptible to heat over 75 °F (24 °C) and will bolt quickly if they get too warm. 

2. Plant in the Shade or Create Some

Broccoli tends to enjoy warm spring days and cool nights. They thrive with six hours of light daily but prefer the gentle morning sun.

Ideally, when it comes to planting your broccoli, you should plant them in a sunny spot that receives shade from the intense midday sun. But if your garden is planted somewhere it is in full sun during the majority of the day, don’t fret. 

You can still plant successful broccoli plants. You will just have to get creative and make some shade for those plants. 

Here are a few easy ways to make shade for your broccoli plants:

A Shade Tarp

The first thing you can do is buy a special shade tarp for your broccoli. A shade tarp is probably the easiest method for quickly creating shade for your plants. Ensure that the shade cloth or fabric deflects UV rays and keeps the plants underneath cool.

Spread the shade only during times of the day when the sun is too hot and bright (typically between 11 AM and 4 PM, depending on where you live). You can easily do so using posts to secure your shade in place and strings to unroll the material when needed.

Plant Near Dense, Leafy Plants

Plant your broccoli near larger plants that can provide a little shade. Green beans or cucumbers are a great option since they can provide dense leafy coverage to protect the broccoli, and these plants generally grow well when planted together. 

Buy or Build a Greenhouse

If you are planning to make a large-scale vegetable garden all year round, you should consider making or purchasing a greenhouse. A greenhouse will keep the direct sun off your plants and can help prolong the growth of many of your plants into the warmer and colder months. 

As you can see, there are quite a few ways that you can protect your broccoli plants from the harsh sun. Just get creative! 

3. Water Your Broccoli Deeply and Regularly 

To prevent bolting, broccoli should be watered frequently, which prevents the soil from growing too hot and stressing out the plant’s roots. That being said, broccoli prefers to live in well-drained soil, and too much water can lead to stressing your plant and early bolting. 

You can tell if you have overwatered your broccoli if, when you press your finger into the soil, it is still very damp. If you notice this is the case, pause watering until the soil has time to dry a bit. 

The best way to prevent overwatering is to feed your plant 1-2 inches of water weekly. That means six gallons per square yard (23 liters per 0.8 square meters) or deeply watering the soil to hydrate 8 inches (20 cm) deep.

Your plant will benefit from infrequent deep waterings better as it encourages them to grow healthy and strong roots. Following the other tips in the article will make this watering practice even more effective.

4. Create Healthy Soil for Your Broccoli To Grow In

This is probably the most critical step when it comes to slowing bolting and creating a healthy environment for your broccoli. 

Broccoli needs soil that:

Drains Well

You can create your own well-draining soil by working 2-3 inches (5-7.6 cm) of sand into the top 5-7 inches of garden soil. This will help with drainage and help prevent your plant’s roots from growing stressed or rotting. 

However, sand tends to trap heat so apply enough mulch above the soil surface to prevent the sun’s rays from heating up the soil.

Alternatively, you can make a raised garden bed before growing broccoli so that you can fill the bed with a well-draining and nutrient-rich substrate.

Is Fertile

Broccoli plants prefer soil that is fertile and full of organic matter. You can also amend the soil using compost instead of sand to improve drainage and aeration and add a slow-release fertilizer to give your seedlings a good start.

Has a pH of 6.0 to 6.8

When your broccoli’s pH is at the right level (between 6.0 and 6.8), your plant will grow better and are far less likely to bolt. This pH range allows your plant’s roots to access as much nutrients as they need to grow. Remember that broccoli is a heavy feeder and will produce good-quality heads when given enough nitrogen.

Retains Adequate Moisture

Brocolli prefers consistently moist soil for its shallow roots to stay cool and continue absorbing nutrients. However, that doesn’t mean they enjoy being in wet soil. That’s why it’s crucial to keep a balance between drainage and moisture retention in your garden soil.

Compost and other organic matter can provide your soil with enough moisture retention.

A soil containing all four of these ideals will produce happier broccoli plants that shouldn’t bolt too early and will leave you with a delicious broccoli supply for much longer. 

5. Apply Mulch To Protect the Plants’ Roots

One of the most important ways you can prevent your broccoli plants from bolting too early is to apply mulch around your plants. Mulch’s job is to provide a protective layer that absorbs harmful sun rays and locks moisture into the soil. 

Now let’s take a look at a few options of mulch you can use to protect your broccoli plants:

Straw

Straw is a very easy mulch to acquire, and it does a fantastic job of blocking out the heat to prevent further stress on your broccoli plant’s root system. You can acquire straw at your local plant or animal feed store. Straw is also available for purchase online. 

Pine Straw

If you live in an area dense with pine needles, you can collect these yourselves or purchase them if you find that easier. The needles provide a dense covering for your plants and will do a great job protecting them from the sun.

Grass Clippings

Grass clippings are a cheap and easily acquired form of mulch. Simply save your bags of grass after mowing the lawn and spread the clippings over your garden to help lock in all the incredible moisture.

Dried Leaves

Don’t have a lawn to mow? Don’t fret. Dried leaves are a fantastic option for those with a steady supply of leaves. Consider using them to mulch your garden instead of raking and throwing away all of those pesky leaves. 

All of these mulch options should work great for protecting your broccoli plant’s roots and aid in bolting prevention. Not only are these great options, but they are also pretty inexpensive, and you should have access to at least one of these in your very own backyard. 

6. Don’t Over Fertilize the Soil

Now we all know and hear about how important it is to fertilize your garden’s soil properly, but it is equally important that we don’t overdo it. 

When fertilizing your soil to grow the best broccoli, you should use a nitrogen-rich fertilizer. However, too much nitrogen can stress your plants and lead to strange deformities in your plants, such as hollow stems.

Apply fertilizers at half-strength. You can add a balanced fertilizer to give your seedlings a boost and add nitrogen-rich fertilizers, such as blood meal, after a month. Applying fertilizers again after harvesting the main head will help encourage the side shoots to develop.

Remember to water your plants directly after fertilizing to unlock the fertilizer and allow it to better penetrate into the roots. Plus, broccoli plants should always be well-watered. 

Using Compost for Healthier Broccoli Plants

Composting is another method of fertilization that can significantly aid in growing healthy broccoli that won’t bolt too soon.

Broccoli plants greatly benefit from high levels of natural material in their soil, which is why you should definitely consider using compost to help fertilize your garden. By adding compost to the soil, you can help strengthen your plants and help them to avoid bolting too soon. 

Plus, it’s free to make your own compost. You can create your own compost from food scraps and yard clippings, grass, leaves, and other organic matter. Just remember that not all foods should be composted, so be sure to do your research before adding them to yours.

If you don’t have a compost bin, you can purchase one relatively cheaply or even make one. It doesn’t need to be fancy. Many people opt for a bucket or even a pile of organic plant matter somewhere in their yard. 

Either way, your broccoli will love the added nutrients! 

7. Plant Broccoli Types That Bolt Less Easily

There are over 27 varieties of broccoli, and each comes with different pros and cons. In fact, certain types of broccoli have been bred to withstand higher temperatures and bolt far less easily. 

So let’s take a look at a few stronger varieties of broccoli that shouldn’t bolt as quickly:

Destiny 

The first broccoli variety, called Destiny, is a hybrid type of broccoli known for being very heat tolerant and is relatively easy to keep happy. It may be more resistant to heat, but you should still take steps to protect your plants from the harsh sun for the best results. 

The Destiny variety of broccoli is known for being heat-tolerant and handling direct sunlight well.

However, Destiny broccoli will still bolt and die if exposed to extreme heat and, therefore, will do better planted in the shade during the spring and fall seasons. Destiny can also handle upwards of six hours in the direct sun as long as the day’s heat isn’t excessive.

Destiny’s ideal garden setup is:

Well-Watered Soil

Just because this plant does reasonably well in the heat, it doesn’t mean it can handle drier soil. And like all broccoli, Destiny prefers well-watered soil with good drainage. 

A Layer of Mulch

To better help you create heat-resistant broccoli, you should use a light layering of mulch to protect your plants and soil from the sun as well as lock in that much-needed moisture. 

Annual Crop Rotation

Destiny broccoli prefers to be planted in different spots every year. Destiny broccoli grows best when moved about the garden since it will zap its preferred nutrients from the soil. 

So, just like with the other standard types of broccoli, Destiny broccoli should be planted in soil that drains well, is properly fertilized, and has been mulched. 

Eastern Magic

Eastern Magic is another hybrid that does pretty well in warmer temperatures and is more challenging to stress, leading to less frequent bolting. 

Eastern magic broccoli is known for being relatively resilient.

It is important to note that although Eastern Magic broccoli is considered heat-tolerant, it will still die if exposed to extreme heat and prefers a shady place to grow. Eastern Magic broccoli also has a higher tolerance for stress than most and is an excellent option for those learning to garden. 

This species plants well in the spring and winter, which means that your Eastern Magic broccoli plant will yield crops in the fall and summer. 

Eastern Magic’s ideal garden setup is:

Soil That Drains Well

Soil that has proper drainage is vital for keeping all varieties of broccoli healthy and happy, including the Eastern Magic variety.

Well-Watered Soil

To keep your Eastern Magic broccoli plant from becoming stressed or bolting, you should water your plant regularly.

A Layer of Mulch

You’ll also want to keep a layer of mulch surrounding your plant. Mulch is a great way to keep your broccoli from bolting and to lock in moisture. Your Eastern Magic plant will do better with mulch as a barrier from the harsh sun.

A Shady Place to Grow

Eastern Magic is more tolerant to the sun than some varieties, but that doesn’t mean it should be planted somewhere too hot and sunny. Broccoli prefers the shade, and your Eastern Magic plant will prefer a shady place too. 

To keep this variety of broccoli happy, you should still follow the above-listed steps, such as planting in the shade. No matter how well your broccoli does in the full sun, the plants ultimately prefer cooler temperatures and should be planted in the winter and spring. 

Belstar

The Belstar Broccoli is an excellent option for those in warmer climates who find their broccoli plants bolting too soon. This variety of broccoli is well suited for planting in the spring or even the summer.

I would recommend still planting this broccoli in the spring for the best results and to avoid the possibility of early bolting. 

The Belstar is known for being stress-resistant. This means that the broccoli plant is less likely to bolt too early or die off due to the stress of its environment.

It’s also known for its ability to grow in warmer weather. Most broccoli hates the heat and will bolt quickly when exposed to higher temperatures. The Belstar, however, is more tolerant to heat and will continue to grow even in warmer temperatures, though it should still be shielded from extreme heat, as it will bolt and die. 

The Belstar’s ideal setup:

Well-Draining Soil

All broccoli varieties grow better in soil that drains well and doesn’t pool too much water around their roots. If water sits on your plant’s roots for too long, this can lead to root rot. 

Mulching

Mulch is a must for most plants, including broccoli, and the Belstar is no exception. An inexpensive mulch should do the job just fine. 

Added Organic Nutrients

You should also add plenty of organic nutrients to the soil. As previously discussed, composting and mulching are fantastic ways to achieve this and keep your broccoli plants happy. 

If you live in a warmer climate, the Belstar is a great option, especially for those newer to gardening and looking for a plant that will be a little more forgiving. 

Sun King 

Last but not least is the Sun King Broccoli plant. If the name hasn’t already clued you in, this hybrid broccoli plant does well in the sun and with warmer temperatures than most. 

The Sun King broccoli is known for its ability to grow well in full sun. The Sun King should be planted somewhere where it will get sun the majority of the day. That being said, it will still bolt and die if the temperatures become too extreme. Besides being heat-resistant, this species can also withstand light frosts.

The Sun King’s ideal growing conditions are:

Full Sun

Unlike most broccoli plant varieties, the Sun King prefers to grow in full sun. 

Well-Draining Soil

Too much water will build up and can kill your broccoli plants, so good drainage is critical when planting the Sun King variety in your garden.

Rich Soil & Compost

The Sun King variety also enjoys rich soil with plenty of compost. A generous helping of organic matter will help stimulate the Sun King to grow and prevent premature bolting.

A Mulch Layer

Not surprisingly, the Sun King prefers a layer of mulch as a barrier between its soil and the sun to achieve optimal growth.

Away From Cabbage

Interestingly, the Sun King variety prefers to be planted somewhere that cabbage has yet to grow since this will result in poor soil quality for your broccoli.  

The Sun King is the best variety for those growing their gardens in a warmer climate or in full sun. It is very hearty and will do well with stress as you learn to navigate its needs. 

8. Reduce Stress on the Plant

Last but not least, the best way to prevent your broccoli plant from bolting is to reduce your plant’s stress. 

Now you may be wondering how you can reduce a plant’s stress and what on earth could stress a plant out. Plants like broccoli don’t feel stressed like you or me, but they can get stressed due to their environment. 

Common Stress Factors

Factors that can stress your plant out include:

Heat

Perhaps unsurprisingly, excessive heat exposure can dry the broccoli’s soil and cause plants to bolt, wilt, and die. Providing your broccoli with shade is extremely important.

Overwatering

When you overwater a plant, you can cause it to soak up too much water and may notice your broccoli changing color or the leaves sagging.

Lack of Nutrients

Your broccoli plant may bolt or not even grow if there are not enough nutrients in the soil. Broccoli prefers nutrient-dense soil that has been well-fertilized and is full of organic matter. 

Overly Cold Weather

Just like excessive heat, when the weather grows too cold, this can kill your broccoli plant. Most broccoli plants can tolerate temperatures as low as 26 °F (-3.3 °C).

Pests

Bugs can undoubtedly put a strain on your plants if left unchecked. This is why you should consider using an organic pesticide that will be gentle on your plants, help prevent bugs, and keep your produce safe for consumption.

Disease

Broccoli can be prone to diseases like Black Rot, Blackleg, and Leaf Spots. Diseases can happen to any plant, and it is best to start treatment as soon as possible in order to prevent spreading the illness around. 

How to Reduce Broccoli Stress

The best ways to reduce your broccoli plants’ stress levels:

  • Keep your plant in a shady place: Your broccoli will grow stressed when overly sunned or overheated, which is why you should always plant them in the shade when you can. Building some shade is also a good option. 
  • Water regularly: Regular watering will keep your plant cool and hydrated.
  • Keep fertilized: Having the proper nutrients in your broccoli’s soil will keep your plant happy and far less likely to bolt. 
  • Plant during the spring and fall: Most broccoli plants prefer to grow during the spring and then are harvested in the summer or winter months. 

You will want to follow all the above tips to keep your broccoli plant as happy as possible. Broccoli plants bolt when they are stressed to hurry and pass on their seeds so that future broccoli plants will be able to grow after they die. 

So when growing your broccoli plant, it is essential to avoid any stressors that will trigger your plant to bolt too early. 

Conclusion 

If you notice your broccoli plants are bolting prematurely, the underlying cause is most likely stress, and there are a few ways in which you can combat this in the future. 

You can prevent premature bolting by:

  • Planting your broccoli during the correct seasons. 
  • Plant in a shady place.
  • Water your broccoli regularly.
  • Keep your soil nutrient dense with good fertilizers. 
  • Use mulch.
  • Reduce your plant’s stress.
  • Plant varieties of broccoli that are known for bolting less.

Dr. Moritz Picot

Dr. Moritz Picot is a horticulture enthusiast and the founder of TheGrowingLeaf.com, where he serves as the lead content writer. He established the website in 2022 as a valuable resource for both gardening aficionados and beginners, compiling all the gardening tips he has accumulated over the past 25 years. Alex has a passion for nurturing plants, transforming backyards into inviting spaces, and sharing his knowledge with the world.

Recent Posts