Bolting happens when a plant blooms and sets seed too early, reducing the yield of your vegetable crop. This coping strategy is activated when a plant is exposed to harsh situations. Thankfully, you can do a few simple things to avoid bolting and boost your chances of a good crop.
What causes plants to bolt?
Plants rely entirely on environmental cues to determine what they should do and when they should do it. Some of the conditions that cause your herbs and veggies to bolt are as follows:
Soil Quality Issues
Poor soil quality will also tell the plant to speed up. Flowering is triggered by a lack of nutrients or the existence of metals, salt, or other contaminants in the soil.
Artichokes, bok choy, broccoli, cabbage, garlic, kale, and cauliflower are heat-sensitive cool-season crops. Therefore, they will very probably go to seed when the weather warms.
Biennial plants have a two-year life cycle and are likelier to bolt during a cold spell in their first season. Therefore, the arrival of unexpectedly cool weather indicates the end of winter and the beginning of the flowering season.
The dry soil encourages bolting, indicating to the plant its do or die time. Conversely, low or no rainfall triggers a fast reproductive cycle, ensuring that the mother plant fulfills its life purpose even if it dies.
Day Length Variations
Flowering is triggered by longer days for some plants. When the days are longer and the nights are shorter, these plants are known as “long day” plants. It’s time to plant flowers when long-day plants like lettuce, spinach, sugar beet, and potato receive more than 12 hours of sunlight per day.
Short-day plants, on the other hand, require longer evenings to blossom. Therefore, these plants will only bloom if they have less than 12 hours of daylight each day. Rice and soybean are examples of these.
Plant stressors include sudden temperature changes, a lack of water, and poor soil. In addition, viruses, insects, and herbivore attacks will hasten the plant’s life cycle. Even severe winds can cause the plant to become overly stressed and bloom early.
What happens during bolting?
The good news is that identifying bolting is simple. When you notice the following signs, it means your plants are bolting:
- You notice a strong stalk emerge from the plant’s foliage, studded with only a few leaves.
- The stalk creates buds, which develop into flowers and seeds.
- You can see that the rest of the plant’s growth has halted significantly.
- You taste that the remaining leaves are growing increasingly bitter.
How do I stop bolting?
The process of a plant bolting is irreversible once it starts. Try one or more strategies to keep your plants from bolting and ensure a healthy development cycle.
- Plant seeds that will not bolt. Look for seeds that are branded “bolt-resistant” or “slow bolting,” as these seeds have been designed to withstand conditions that cause bolting. Also, look for heat-treated onion sets when growing onions. For example, these onions can tolerate high temperatures and are less likely to form blossom buds in hot weather.
- Sow your seeds directly. Carrots, turnips, beets, radishes, and many herbs, which are sensitive to bolting due to root stress, grow best when direct sowing outdoors rather than transplanting. This permits them to build their root systems without interruption.
- Mulch your soil to keep it cool. When warm soil heats the roots of plants with heat-sensitive roots, such as broccoli, cauliflower, and cilantro, they bolt. Spread a layer of mulch on the topsoil to cool things down and moist and prevent them from overheating.
- Make sure you’re using the right fertilizer. If you use fertilizer on your plants, be sure it’s one designed for developing leaves and stems rather than one that promotes bloom growth. Fertilizers that promote green growth typically contain more nitrogen.
- Plant your crops when the weather is cooler. Early spring planting may still be relatively warm, depending on your local environment. Try growing spring veggies in the fall, when temperatures are less likely to be unseasonably warm. Kale, cabbage, and bok choy are among brassicas that can be grown in the spring or fall.
- Give your cold-weather crops some shade. If you reside in a hot region, be careful to give cool-season vegetables like radishes, lettuce, and spinach some shade. Even vegetables that thrive in full sun can bolt if the temperature is excessively hot. Planting these crops alongside taller plants, like corn, will give natural shade, or you can set up shade cloth covers during the extra-hot daytime conditions.
Can you reverse bolting?
If you catch a plant in the early stages of bolting, you can sometimes stop it from bolting completely by snipping off the blooms and flower buds. In other plants, such as basil, the plant will continue leaf production and halt bolting.