by Connie Oswald Stofko
What is bolting versus flowering?
In both cases, the plant produces a flower.
Flowering occurs as a natural part of the plant’s life and generally doesn’t affect the taste of leaves.
Bolting occurs when a plant is stressed, often because the temperatures got too warm for that plant’s liking. The plant wants to reproduce before it dies, so it sends up a flower that will go to seed. Bolting diverts resources away from the leaves, which can affect the taste — and not in a good way. The leaves can be inedible.
Jen Weber, vice president and manager of Mike Weber Greenhouses at 42 French Rd., West Seneca, takes us through what you need to know about herbs that flower and herbs that bolt.
Herbs that bolt
Cilantro
Cilantro gets bitter when it bolts.
Plant cilantro in spring, between Memorial Day and Father’s Day, Weber said, and use it until the weather gets hot.
As soon as you see a flower bud start to form, cut it off. That will prolong the harvest of your leaves, she said.
Don’t just cut the bud off at the top; cut the stem all the way down to the leaves. If you’re doing it right, you’ll cut off a stem that is a quarter inch or half inch long.
Keep cutting the buds off. If you see a white flower, it’s too late. Your cilantro will be bitter.
If it gets away from you, you can buy a new cilantro plant at Mike Weber’s. They keep planting cilantro in batches, so they have new, fresh plants. You can also buy their Gardener’s Own brand plants at Wegmans.
Or you can skip the hottest part of the summer and buy a cilantro plant in mid- to late-August when the nights are cooling off, Weber said.
Unfortunately, cilantro seeds won’t overwinter outside in our area, so even if you let your plant go to seed outside, you won’t get a new crop in spring. You could save the seed and try to start a cilantro plant inside next spring.
Parsley
Parsley bolts, but that doesn’t affect the flavor of the leaves, so you can let parsley go to seed. The seeds do overwinter, so you can have more parsley next year.
The parsley flower is ugly, but edible. The flower contains a lot of pollen, so if you’re allergic to pollen, don’t use the flower.
Weber added that you can get multiple harvests from one parsley plant. Parsley leaves grow back fast, so go ahead and cut them off and use them. Don’t be timid; more leaves will grow in their place.
Arugula, watercress and sorrel
You can think of arugula, watercress and sorrel as leafy vegetables, or you can think of them as herbs. They all bolt.
Bolting makes the leaves of these plants very bitter, and it’s especially true of arugula.
“Arugula is always bitter — and I like arugula — but one bite and you’ll spit it out,” Weber said. “You need to keep cutting the flowers off. When half the plant is flowers, toss it out.” And as it gets older, the leaves get tough, so you can tell just by looking at it that it’s past its prime.
Herbs that flower
Chives
Some chives flower once in spring while other varieties can flower off and on all season. The flowering doesn’t affect the taste of the leaves.
The flowers are pretty and edible.
Basil
When a basil plant flowers, it won’t affect the flavor of the leaves.
Clip off the flowers and the plant will get bigger.
Thyme, marjoram and oregano
Thyme, marjoram and oregano get small, pretty flowers. The flowers don’t affect the flavor of the leaves.
The flowers are edible, but they don’t taste like anything. You don’t really notice they’re there, Weber said.
Mint
Mint gets really big flowers, and the flowers don’t affect the taste of the leaves.
You can eat the flowers.
Because mint can spread easily in your garden, you may want to snip off the flowers before they go to seed.
Hi Charlotte, thanks for that tip!
When cilantro does gets away from you and flowers you can keep a few plants and let the seeds develop. Harvest the seeds, roast and grind them (now it’s called coriander) and use them in sweet or savory cooking.
Hi Diane, thanks so much! Did you know you can subscribe? It’s free! When you subscribe, the newest edition is emailed to you every Tuesday so you don’t miss a thing. You can subscribe here.
New gardener. I love the site, please keep doing what you do best. Information is easy to read and understandable. Like your step by step approach to gardening. Be safe
Hi L Earl, that’s great! Thanks for sharing.
I live in Zone 5 and my cilantro and parsley came back this year. Some might be from seed. Where I plant my herbs is on the side of my patio which is about 3 feet off the ground.
It sounds like cilantro might overwinter in warmer spots, but a true 5a, 5b or 6a zone might be too cold. Thanks for sharing, Jenn.
I agree with Peggy!!! We are a zone 6a in Ohio and I have a garden in the corner where my garage and house meet. It’s on the south side of my house so it likely stays a bit warmer than much of my yard. One year I grew cilantro. I can’t recall which variety but every year since, the first thing to sprout are literally thousands, perhaps hundreds of thousands, of cilantro seeds all over my yard. I’ve never seen anything like it. I let it go to flower, I have honeybees that cover it en mass all Spring/early Summer. Rinse and repeat every year.
Peggy, that’s great. I’m sure many gardeners envy you. Thanks for sharing!
I don ‘t know why. One variety I plant is calypso. Plants that start in fall will over winter and come warm spring weather, they perk up and I can harvest leaves or let them go to seed. I have more then t can ever use!
Peggy, I’m with Meredith. How do you do it? Do you have an especially sheltered spot? Why do you think it works for you? Please let us know so I can share with others.
Lucky you Peggy! If you have any tips I’d welcome them; maybe recommend a certain plant or cultivation tips etc
I beg to differ on cilantro not over wintering. I have a perpetual cilantro patch that is constantly in flux; plants setting seed, plants in bloom, new plants coming up. I almost always have enough for fresh use and save seeds for use as coriander, and some to leave for future sowing. Come spring, there will be a fresh batch of beautiful, young plants to use.
Seed does not, however, germinate well in summer.
Meredith, that’s helpful information. Thanks for sharing!
I also have cilantro that has re-seeded for years but the leaves never really develop well and plants quickly bolt. The seeds – known as coriander are definitely worth harvesting! When the plants are just starting out I use the whole plant, root and all, for that great fresh cilantro taste but I admit it’s easy and cheap to just buy it in the quantity I want for cooking throughout the summer.
Sue, thanks for the question!
Yes, I thought since I planted two years ago, maybe the plant with foliage was there last year and I just didn’t notice. It was out in the open with not much protection but we did have pretty good snow cover for quite a while so that must have helped. Thanks for the info.
Jen Weber says: Cilantro isn’t a biennial. (A biennial has foliage the first year and flowers in the second year. It doesn’t mean you plant it every other year.) If you had the cilantro planted somewhere protected, like up against the house, your plant could have overwintered. In Western New York, generally neither the plants or seeds overwinter, but maybe you have a spot where they can come back. Lucky you!
I’m relieved to read that it’s OK to let parsley go to seed. I had a surprise plant that got away from me and now the flower stalk resembles queen Anne’s lace. I disagree with the statement that cilantro doesn’t overwinter. I have a few plants that overwintered and they’ve now gone to seed. I wondered if they’re biennials because I don’t recall planting them last year, but I did the year before.