The most common cause of bolting broccoli is heat. Broccoli is a cool-season plant and does best with a soil temperature between 18°C and 24°C (65°F to 75°F). As the summer temperature starts to rise above this, the broccoli roots overheat and focus on self-preservation.
The cool season shrub begins to generate seed once more as the days grow longer and the sun's rays become more intense in preparation for the summer months.
Bolting, or flowering, in broccoli can also be brought on by other pressures on the roots, such as getting rootbound or being injured. Broccoli grows best in rich soil with a pH range of 6.0 to 6.8. Every two to three years, I test the soil in my garden to use a soil testing kit.
Preventing the root from getting too heated is the greatest approach to stop your broccoli from bolting. Put a thick coat of organic mulch, like straw, over your broccoli plants to protect the soil from the sun, retain moisture, and insulate the ground.
While sunlight is a major catalyst for bolting, protecting the broccoli from the sunlight can be quite beneficial. You may offer shade in many different ways. You can cover your broccoli with row covers, hang shade fabric, use a patio canopy, or around it with tall, quick-growing plants.
If you plant a small amount of broccoli about once a week as opposed to all at once, your plants will be in different phases if the temperature suddenly becomes hot. They won't all respond to the heat in the same way in this manner, and some growth stages won't be as likely to bolt.
If you grow broccoli indoors, take sure to transplant it before the roots in the pots get tangled. Move the delicate seedlings into big pots until they're ready for transplanting if the climate is still too unpredictable for them.
After you pluck the primary head of broccoli, fresh side shoots will continue to sprout. Compared to the primary head, these side branches are much less likely to bolt. Consider plucking earlier, smaller heads before plants bolt as a scorching summer approaches.
You may get your broccoli ready even before heat arrives by planting it in good, healthy soil, which will aid in its speedy growth.