How can we both anticipate and manage plants that go to seed?
Background: Preventing Bolting Plants
When flowering plants reach maturity and are pollinated, they are able to produce seeds that form the foundation of the next generation of that particular species. In this stage of the plant’s life cycle -- towards the end, that is (even if only for the season) -- the plant directs much of its energy towards producing these seed structures. For some plants, such as salad greens and herbs, this new allocation of energy is damaging to what humans desire most of the plant: the leaves. While the leaves receive less nutrients, the seeds get all of the plant’s attention -- called bolting when it happens earlier than expected. Of course, the flowering process is desirable for other plants whose seeds (fruit) we harvest for consumption.
The introduction of stressors such as changes in the length of day and hotter days sends signals to the plant that it may be dying soon, causing the plant to go to seed. While this is inevitable, it is important to take actions to extend the life of your plant in order to gain the maximum harvest potential, in addition to keeping the leaves edible and tasty.
Students will be able to...
Understand the actions that can be taken to keep certain plants from going to seed
Treat plants that can still produce after they have gone to seed
bolting /ˈbōltiNG/ verb. - (in plants) the premature development of seeds
1. Gather your materials. You will need the following supplies:
pruners · plants such as salad greens, herbs, or brassicas, carrots, and other vegetables
2. Watch the following YouTube video to see a demonstration of how to prevent and treat plants bolting to seed. Then, follow along with the remainder of the lesson by reading the steps below.
3. Maintain a cool environment for leafy plants that tend to bolt by watering frequently, and adjusting watering intensity for particularly hot days. Also be sure to sow during the cooler parts of the season (early spring or before fall). Plants under consideration for fear of bolting are mostly those whose seed-bearing structures humans do not harvest for consumption. It is also important to harvest greens and herbs frequently, so the plant must create more leaves in order to photosynthesize effectively.
4. Notice any flowering of the plants, and snip off the buds using your hands or pruners. Since the flower precedes the formation of the seed, by snipping off the bud, the plant has nowhere but the leaves (and roots) to allocate energy (at least for a short time). Some plants -- such as cilantro -- may lose their flavor profile at this point in time, and no further action is very effective other than to collect the seeds for later use.
5. Some plants that make it through the flowering stage and begin to create seeds remain edible, such as basil. As before with the flowers, simply pluck or clip the seeds that have appeared at the top of the plant, and compost the clippings. The basil should begin to produce leaves again, but may need tending to often.
Download the PDF version of this lesson plan: