Quick answer: Yes, you can eat basil leaves after the plant flowers. The leaves may have a slightly different taste, but they are still edible and safe to consume.
Does Basil Change After Flowering?
Basil can develop some changes after the plants start flowering. The most noticeable difference is the taste. Once basil begins flowering, it starts producing essential oils that give the leaves a more pungent, spicy flavor. The leaves may also become slightly tougher and woodier in texture.
You may notice other physical changes as well. The leaves tend to get smaller. Their color may dull from a vibrant green to a paler olive green. The plant’s energy gets diverted from leaf production to forming flowers and seeds, so the foliage growth slows down dramatically.
None of these changes make the leaves inedible. The taste is simply stronger. The texture is a bit chewier. But the leaves still offer the sweet essence of basil even after the plant flowers. There is no toxin or chemical change that happens to make the leaves unsafe to eat.
Why Does Basil Taste Different After Flowering?
The reason flowering basil has a more pronounced flavor all comes down to chemistry. Here’s what happens inside the plant:
- Flowering triggers an increase in essential oil production. These are the compounds that give basil its distinct aroma and flavor.
- One essential oil called eugenol increases more dramatically, altering the flavor profile.
- Chlorophyll production drops off as the plant’s energy goes toward flowering instead of leaf growth.
- The reduction in chlorophyll removes some of the grassy, green flavor notes.
So in summary, the leaves end up packed with more essential oils, but less of the compounds that give basil its sweetness. The result is a more concentrated, spice-filled flavor.
Basil Essential Oil Composition Changes During Flowering
Researchers have analyzed the exact chemical changes that happen in basil leaves post-flowering. One study published in the Journal of Essential Oil Research examined the differences inessential oil content between non-flowering and full-flowering basil plants.The results were as follows:
| Essential Oil Compound | Non-Flowering Leaves | Flowering Leaves |
|---|---|---|
| Eugenol | 8% | 21.5% |
| Linalool | 27.5% | 18.2% |
| 1,8-Cineole | 6.5% | 9.8% |
| Camphor | 6% | 5.6% |
As you can see, there was a huge spike in eugenol content once the plants flowered. This compound has a very pungent, clove-like aroma. The sweet, floral linalool decreased during flowering. So the overall flavor profile shifts to being more sharply spicy.
When Does Basil Usually Flower?
Sweet basil varieties flower in mid to late summer. This is around 60-100 days after sowing the seeds. Some gardeners may see basil start flowering sooner, while others might not notice flowers until early fall.
The timing depends on a few factors:
- Variety – Some types of basil are bred to resist flowering. Italian basil can go weeks longer without blooming compared to other types.
- Temperatures – Hot weather speeds up flowering. Cool summer temperatures delay it.
- Sunlight – Flowering happens faster when basil gets at least 6 hours of direct sun daily.
- Mature Plant Size – Larger, older basil plants tend to bloom before smaller ones.
- Pruning – Cutting off flowers as they form delays flowering.
- Stress – Any type of stress like drought or overwatering can trigger earlier flowering.
Can You Prevent Basil From Flowering?
It takes a little extra care, but you can prolong the vegetative growth phase of basil and prevent flowering. Here are some effective techniques:
- Pinch off flowers – As soon as you spot flower buds forming, pinch or snip them off. Keep doing this periodically and you can delay flowering for weeks.
- Prune aggressively – Cutting the plants back by a third encourages more leaf growth instead of flowers.
- Use shade – Giving basil bright but indirect light can slow down flowering.
- Watch watering – Avoid drought stress, but also don’t overwater. Keep soil moderately moist.
- Fertilize often – Apply diluted liquid fertilizer every 2-3 weeks during the growing season.
- Pot up container plants – Repotting into larger containers delays flowering.
With perfect conditions, you may be able to go an entire growing season without seeing flowers on your basil plants. But flowering is inevitable as the plants reach maturity. The best approach is to simply keep harvesting the flavorful leaves.
How Does Flowering Affect Harvesting Basil?
Once basil starts blooming, harvests become a bit trickier. Here are some tips for continuing to pick basil leaves after flowering starts:
- Harvest more frequently – Pick leaves at least every week to encourage more growth.
- Target outer leaves – The youngest leaves at the tips still have the best flavor.
- Remove flowers – This redirects energy back to leaves.
- Cut back plants – Radically pruning stimulates new growth.
- Harvest early in day – Leaves tend to be crisper in the morning.
- Preserve extras – Freeze or dry any surplus leaves you can’t use right away.
As flowering winds down, harvests will become even sparser. At this point, you can opt to pull up the plants and replant with fresh seedlings for a second crop.
Should You Remove Basil Flowers?
It’s best to remove most basil flowers to get the longest harvest window. But leaving a few flowers can be beneficial too:
- Keep flowers if you want to collect seeds – Just allow one plant to finish blooming and set seed.
- Prune selectively – Leave flowers on plants you don’t harvest often.
- Allow some flowers for pollinators – Bees love basil blooms!
The bottom line is judiciously plucking most flowers helps direct energy to leaf production. But you can make exceptions if needed.
Can You Use Basil Flowers?
While we remove basil flowers to prolong leaf harvests, the blooms aren’t useless. Basil flowers have some culinary uses:
- Add to salads for color and a mild basil flavor
- Use as garnish on pasta, pizza, soups, and more
- Infuse in oils for a floral basil flavor
- Dry for culinary use – they keep their color well
- Pickle in vinegar for a caprese salad garnish
- Float in drinks like chilled wine, lemonade, or cocktails
The flowers have the sweet, aromatic qualities of basil with floral notes. Both the petals and buds can be eaten.
Can You Propagate Basil From Flower Cuttings?
Interestingly, taking cuttings from flowering basil stems can be an effective way to propagate new plants. Here are some tips for success:
- Take 3-4 inch stem cuttings below a flower/leaf node
- Remove any flowers and lower leaves
- Treat cut ends with rooting hormone (optional)
- Place in water/soil to root for 2-3 weeks
- Transplant successfully rooted cuttings
As long as the mother plant is still actively growing despite some flowering, the stem cuttings can root readily. The resulting plants may take longer to flower since they are started from juvenile cuttings.
Common Questions
Why does my basil taste bad after flowering?
Once it begins flowering, basil tends to lose some of its sweet flavor and take on a sharper, more bitter taste. This is caused by chemical changes in the essential oil composition of the leaves. The spike in eugenol gives the basil a strong clove-like flavor that not everyone enjoys.
Can I use flowering basil for pesto?
Yes, you can still use flowering basil leaves to make pesto. The flavor will be more pungent. To balance out the strong taste, add extra pine nuts, parmesan, or a soft white cheese like ricotta. The flowers themselves can also be added to pesto for color and flavor.
Should I prune basil before it flowers?
It’s a good idea to prune basil about 4 weeks before its expected flowering time. Cutting the plants back by about one third redirects their energy from flowering to producing new growth. Just be sure not to prune too early or you could end up delaying the harvest window.
What can I do with basil that has flowered and gone to seed?
Once basil goes to seed, the leaves won’t have much flavor or texture left. At this point, pull up the old plants. You can save some seeds for planting next year or sprinkle them on salads. Replace the old basil plants with fresh seedlings so you can continue harvesting.
Should I deadhead basil flowers?
It’s best to pinch or snip off most basil flowers as they form. This is called deadheading. It redirects the plant’s energy from seed production back to leaf and stem growth. Allow just a few flowers for pollinators and collecting seeds.
Conclusion
Letting basil flower doesn’t need to spell the end of your harvest. While the leaves take on a more pronounced flavor, they still offer that unmistakable essence of basil. With frequent harvesting and careful maintenance, you can continue picking tasty leaves all season long – even after the plants start blooming.