Growing broccoli at home, all by yourself, can be a little bit tricky as broccoli is a heavy feeder and also has very specific temperature requirements, but still, with a little extra effort and hard work you can get beautiful, large, and vibrant green broccoli heads! However, there are a few instances when people discovered that their broccoli plant is not growing any head at all, or is growing extremely small heads. Here, we will check out, why is my broccoli plant not growing heads?
‘Buttoning’ is a term used when your broccoli plant produces small broccoli heads, (which are poorly formed) or no heads at all.
How long does it take for a broccoli plant to grow its first head
Before exploring the reasons as to why your broccoli plant is not growing broccoli heads or maybe growing a very few heads, it is important to know how long does it take for a broccoli plant to grow its first head and what are the ideal conditions under which broccoli plant will grow bright green heads with compact florets.
The first important question is how long does it take a broccoli plant to grow head.
Well, there are various factors on which the speed of the growth of the broccoli plant depends, for example, at what time of the year are you growing your broccoli plant, what variety of broccoli are you growing, what are the climatic conditions of the place where you have decided to grow your broccoli, the quality, and type of soil, the temperature of the place, the amount of sunlight that your broccoli plant receives, etc.
In an ideal condition, in which your plant is receiving sufficient sunlight, and water, and has all the optimum conditions for its growth, the broccoli plant would take about 90 to 200 days or about 3 months to produce broccoli heads.
A fully grown broccoli head is deep green and color and has tight and compact florets. The size of the broccoli head varies from plant to plant and from variety to variety, but usually, their size lies between 10 cm to 18 cm or about 4 to 7 inches.
Read Can broccoli grow again after cutting?
Why is my broccoli plant not growing heads
If you are worried about your broccoli plant not producing head or you want to simply ensure that your broccoli plant produces head on time, then here are some of the conditions that you need to ensure are being full filled –
1. The perfect soil
Broccoli is a heavy feeder and therefore requires the perfect kind of soil for its optimum growth. You need to make sure that the kind of soil you are using for growing broccoli, drains well. The soil should be well fertilized and moist.
Broccolis require the soil to be slightly acidic in nature. They grow best in soil with a pH of 6.0 to 6.8. One of the reasons for your broccoli plant not producing heads could be because your soil is too acidic.
If the soil has a pH below 6.0 then you can add some acid compost to it and if the pH of the soil happens to be above 7.0, then you can add some granular sulfur to it.
After making sure that your soil has the perfect pH level for the growth of your broccoli plant, you need to also ensure that the soil drains well. Usually, adding organic matter, such as compost or manure can help in water drainage.
It is also a good idea to fertilize your soil every 20 days for getting the best results. Water your broccoli plant well after fertilizing the soil.
Read What Layer of Soil Is Best for Growing Plants
2. Adequate sunlight
Broccoli requires a very good amount of sunlight in order to grow properly. It is extremely important to ensure that your broccoli plant is receiving at least 6 to 8 hours of sunlight on a daily basis.
Lack of sufficient sunlight can lead to your broccoli plant not producing heads on time, or even if it produces heads, they might not turn out to be as healthy and green as they should ideally have been.
Similarly, excessive sunlight or overexposure to strong sunlight can cause your broccoli plant to bolt and thus result in producing fewer heads or no heads at all.
3. The right temperature
Broccoli is a cool-season crop and usually cannot tolerate a lot of heat. An ideal time to grow your broccoli is in early spring for a summer harvest. If you are living in hotter places like Southern California then you should start planting your broccoli seeds in late September or early October.
Broccoli grows the best at a temperature that is between 18° C to 22 °C or 65 – 70° F.
If you are growing your broccoli plant at a temperature considerably higher than that, then your broccoli will start to bolt that is it will directly go into the flowering stage without producing broccoli heads.
So if you are living in such hot areas then you can go for certain varieties of broccoli that have a high tolerance for heat for example the Sun King variety of broccoli has a high tolerance for heat and is specially bred to grow in areas like Southern California where the winters can get a little warm. It is also known to produce the biggest broccoli heads.
Also if the temperature falls below 10° Celsius or 50° F, then this could also lead to buttoning or the formation of poorly formed small broccoli heads or no heads at all. In some cases, the broccoli plant might not even be able to survive such extremely cold temperatures.
A good idea would be to start planting your broccoli seeds about 6 weeks before the last frost-free date.
Using row covers is a good way to protect your broccoli plant from harsh and strong sunlight if in case you feel that your broccolis are over-exposed to the sun. Row covers also help in keeping the soil cooler and thus help in hot weather.
Read Can broccoli grow again after cutting?
4. Proper spacing between each broccoli plant
Once you transplant your broccoli seedlings into the garden bed or a larger area, the first thing that you need to ensure is that there is adequate spacing between each of the broccoli plants. Broccoli grows into huge plants once they mature and thus requires a large amount of space.
Make sure that you are spacing your broccoli plants with at least a gap of 15 to 20 inches apart from each other.
If the broccoli plants are sown too close to each other, then they might end up using the energy for survival and thus won’t be able to produce broccoli heads.
5. Avoid overcrowding your broccoli plant
Just like inadequately and improperly spacing your broccoli plant can reduce the chances of production of broccoli heads or produce heads of very poor quality, similarly, it is important to ensure that while you are transplanting your broccoli to the larger area, you are not overcrowding the space by growing too many broccolis in a limited amount of space.
Overcrowding and improperly spacing the broccoli plants can lead to them competing for space and nutrition as a result of which your broccoli plant might end up producing only a very few broccoli heads, which might not be of the best quality.
Read Why are my broccolis growing out to be bitter?
6. Sufficient water for their growth
Broccolis, just like other green leafy vegetables, require a good amount of water for their maximum growth. Broccoli plants require about 1 inch to 1/4 inches of water every week. Always make sure to check the soil moisture. If the soil at any point feels dry then immediately dampen it.
Yet another way to check if your soil is lacking moisture is to check if the soil, present a few inches below the surface is moist or not. If this soil feels dry then it is a sign that you need to water your broccoli plant more often.
Another point to keep in mind while growing broccoli is that broccolis have a very low tolerance for drought. A broccoli plant cannot grow at all in such conditions.
So one of the reasons for your broccoli not producing heads could be that you are not watering it adequately.
Now once you have ensured that your fulfilling all the conditions mentioned above here are some of the things you can look into if in case your broccoli plant is still not growing head.
Read How to Grow Greener Broccolis?
7. Improper water drainage
As already discussed above, the broccoli plant requires the soil to be able to drain well. Loose and well-draining soil is an important requirement for growing your broccoli as this promotes healthy root growth.
If drainage is the problem that you are facing while growing your broccoli then you don’t need to worry as there is a way out for this if you want to improve the soil drainage.
Mulching can help in improving soil aeration, eventually helping in soil drainage. Mulching is the process in which you add some organic matter to the soil for example manure or compost, which will help improve the soil drainage.
Mulching is an excellent way to help prevent your broccoli plant from bolting and thus help your broccoli plant to grow heads instead of directly going into the flowering stage.
One of the reasons that your broccoli is bolting is your broccoli plant is growing too tall. This is when your plant will start to flower at maturity, without producing any heads, in order to complete its reproductive cycle.
So in a lot of cases, you will find your broccoli plant growing tall and bolting without forming any broccoli heads.
Read When and how should I plant broccoli in Georgia?
8. Control over pest attack
Pest attacks can lead to the production of very few broccoli heads and even no heads at all. Using fertilizers containing potassium can help to improve the plant’s metabolism and resistance to diseases.
Controlling pest infestation is extremely important to ensure that your broccoli plant is producing healthy broccoli heads. Using row covers can help keep those nasty insects and pests at bay! You can also use neem-based insecticides to control pest infestation.
9. Your plant not getting the right amount of nitrogen
As already discussed that broccoli is a heavy feeder and just like other vegetables from the cabbage family, broccoli too requires a good amount of nitrogen for the production of healthy broccoli heads.
It is important to ensure that you are fully filling the nitrogen requirements of your broccoli plant for its healthy growth and development.
If in case the soil that you are using to grow broccoli is not rich in nitrogen, then you can simply use nitrogen-rich fertilizers.
Some good alternatives for chemical fertilizers for your plant can be – blood meal, hoof, feather meal, compost, manure, etc.
Yet another way to compensate for the lack of nitrogen would be to grow leguminous plants around your broccoli.
The rhizobium bacterias, which are present in the root nodules of such leguminous plants, convert the nitrogen present in the air into water-soluble nitrogen compounds called nitrates and they can help in fulfilling the nitrogen requirements of your broccoli plant.
Read How can I grow broccoli by using its stem in water?
Bolting is the process in which your broccoli plant starts to flower in order to produce seeds.
Some of the reasons that can cause your broccoli to bolt could be – stress, such as extreme temperatures, which are too high or too low, transplanting your plant too late etc.
Bolting is basically a survival mechanism in many cool-season crops, where the plant tries to quickly complete its reproductive cycle before it dies and thus it leads to improper formation of broccoli heads which are too tiny and sometimes, even non-existent! In other words, bolting can result in your broccoli plant directly going into the flowering stage without producing any broccoli heads.
Thus, making sure that your broccoli plant is growing within the ideal temperature range and conditions is very important to avoid your plant from bolting.
So, we see that ‘buttoning’, or the condition of your broccoli plant producing extremely tiny heads or no heads at all, is often a result of the broccoli plant going through stressful environmental conditions. Thus providing your broccoli plant with ideal and optimum growth conditions and also controlling pest attacks on your plants can result in the formation of perfectly healthy broccoli heads!
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I’m Elsa, and I love gardening. I started GardeningElsa.com as a resource for other gardeners, and I offer expert advice on gardening topics such as plants, flowers, herbs, and vegetable gardening. On my website, I share my latest tips and tricks for creating beautiful gardens. When I’m not working on my website, you can find me in my own garden, tending to my plants and flowers. Read more about me.