What Does Bolting Mean?

Bolting is just another way of saying that a plant is going to seed. Its time in the garden—whether that was around 30 days, 90 days, or 720 days—is coming to an end.

We get really excited when fruiting plants produce seeds because that means it's finally time to pick delicious tomatoes and cucumbers from the vine. But for herbs and leafy greens, going to seed means the end of the harvest party.

Let's look at why plants bolt, how you can prevent premature bolting, and what to do once your plants are going to seed.

Why Do Plants Bolt?

Plants typically bolt for one of two reasons. They're likely either stressed or just plain tired of growing. Either way, the plant switches from putting effort into its own survival to looking toward the survival of its own kind. It does this, of course, through producing seeds.

Plants have a strong desire to continue their genetic line for generations to come, and the formation of seeds is how they ensure that dozens, if not hundreds, of copies of themselves will exist long, long after they die.

Plants Bolt When It's the End of Their Lifespan

Each plant has a set lifespan that's built into their DNA, and they can feel when it's coming to an end. Arugula, for instance, generally only spends about 60 to 75 days in the garden. At the end of that time, the plant will be like, "Well, it's just about that time to reproduce so I can make sure there are arugula seeds for next season." In the picture below, you can see bolting arugula.

Plants Bolt When It's the End of Their Optimal Time to Grow

Certain environmental triggers can also cause stress in plants and push them toward taking action to ensure the survival of their kind sooner rather than later. A change in temperature is the most common trigger, though running out of space to grow or using up all the nutrients in the soil can also stress a plant out and cause it to bolt.

You may notice that certain plants begin to bolt as spring turns to summer. Certain plants like cilantro and lettuce and dill are programmed to grow in cooler temps and shorter days. So as the days grow longer and warmer, the plants have a little internal alarm that alerts them it's time to go to seed. Beep beep! It's no longer the optimal time for us to grow!

If you plant something outside of its preferred growing season, prepare yourself for some premature bolting. You should, for instance, only plant cilantro in hot weather if you want to see how fast the plant can produce flowers. This is why it's really important for you to study up on the plants you want to grow and know which range of temperatures they generally prefer. (Though some gardeners plant cilantro just for the dainty white flowers, which you can see below.)

Signs Your Plant Is Going to Seed

Here are the telltale signs your plants are bolting.

Sign #1: Tall Main Stalk

The most obvious sign that your plant is beginning to bolt will be the sudden vertical growth of the plant's main stalk. Your mustard greens can all of a sudden stretch 5 feet tall. Small lettuce plants can suddenly become towering giants. Plants with lots of stems, like parsley, will send up several tall stalks that are much thicker than typical stems.

In the picture below, you can see a bolting spinach plant that's now taller than the kale and pepper plants.

Sign #2: Change in Leaf Shape

As the stem grows up, the leaves that form on the plant will look different than the leaves of the plant back when it was happy and healthy. When cilantro bolts, for example, its leaves will grow thinner and start looking more like dill or carrot leaves. Bolting parsley leaves become long and narrow. And bolting arugula leaves will become much more serrated than the original leaves of the plant.

Below, you can see bolting spinach, with leaves that resemble an arrowhead instead of the nice, rounded leaves we're used to.

Sign #3: Formation of Flowers

If you're not sure whether your plant is going to seed or not, you'll know once you see little florets forming at the top of the plant. These flowers will bloom, attract a ton of beneficial insects, and then eventually dry out. Inside will be dozens, if not hundreds, of seeds for next season's plants.

The flowers of bolting plants are some of my favorites—basil with its gorgeous purple flower spikes, arugula with its dainty white petals, dill with those stunning yellow umbels.

Sign #4: Change in Flavor

When a plant starts focusing on seed production, it's no longer sending any of its energy to the leaves or the roots. It's a sad but inevitable day when your cilantro leaves lose their wonderful flavor or your radishes turn starchy and bitter.

When lettuce bolts, you might notice a milky sap coming from the base of the plant, in addition to the bitter taste in the leaves. The leaves are still safe to eat, but you may find them too rubbery and unpleasant.

How to Prevent Bolting

Going to seed is inevitable, but you can keep your plants in your garden without them bolting for as long as possible by growing them under their preferred conditions. Here are some ways to delay plants going to seed.

Grow Plants From Seed in the Garden

If at all possible, direct sow seeds for annual herbs like cilantro and dill and then small leafy greens like spinach, lettuce, and arugula. Plants sown from seed right in the garden where they'll grow tend to bolt slower than those purchased as seedlings or started indoors and then transplanted into the garden.

Pictured below is bolting parsley alongside bolting lettuce.

Grow Plants During Their Preferred Season

Once you know a plant's preferred growing season (cool, warm, or hot), then you can try to add that plant by seed or plant start as early as possible at the beginning of that season. Spinach, for instance, loves cool weather. You can plant it well before your last frost date in the spring. If you wait till you only have a couple weeks left when the temps will stay below 75°F, it's too late to grow spinach. Wait until the return of cool weather for best results.

One thing to keep in mind is that big box stores don't really take a plant's preferred growing season in mind when they're selling you plants. You might see cilantro on sale, even though it's already much too warm to grow cilantro.

If you want to learn how to get the timing right in your garden, download our free 2024 Garden Calendar. This is a great resource we created to help you know when to plant things like herbs and salad greens based on your climate.

Look for Certain Varieties When Shopping for Seeds

Look for seed packets that say things like "slow bolt" or "long standing". That means the plants have been bred to last longer in the garden. If you're coming up on warmer weather, you could also look for more heat-tolerant varieties. Jericho romaine, for example, is known for being able to grow in summer weather long after other lettuce plants have gone to seed.

Harvest Regularly

Cut the older, outer leaves from your plant on a regular basis. Harvesting regularly this way keeps the plant healthy and gives you lots of leaves to enjoy (and perhaps freeze) while they're at their peak flavor and nutrition. If you notice an immature flower stalk beginning to form, go ahead and snip it off. That can buy you perhaps a couple weeks more.

Pictured below is bolting basil with developing flowers that can be pinched off.

Provide Shade

Protect your plants from the hot afternoon sun by covering your garden with shade cloth or by planting taller plants around those that are sensitive to rising temps. Shade cloths can protect plants from the full force of the sun, keeping the air underneath cooler by as much as 10 to 20 degrees and helping to retain moisture. The effect is to basically trick your plants into thinking it's still their ideal climate for a while longer.

Taller plants can also provide much-needed shade and keep the soil cooler as the day grows warmer. Don't worry about your lettuce or basil getting full sun—these herbs and leafy greens can continue to grow with just 4 to 6 hours of sun a day.

Succession Plant

Succession planting is when you direct sow new seeds for the same plant every couple of weeks. When one set of arugula plants start to bolt, for instance, you'll have another set of arugula plants growing that will soon be ready to harvest. This planting method doesn't prevent your plants from bolting, but it gives you a more continuous supply of the flavors you love.

Keep Plants Watered

Increase your watering schedule to correspond with the rise in temps. You might need to water tender leafy greens like lettuce and spinach every single day so that the soil stays moist. These plants have shallow roots that can't reach very deep into the soil for water, so they'll feel water stress much faster than other plants. Keeping them watered on warmer days is like a cooling balm to them.

Pictured below is some bolting mustard greens.

What to Do When Your Plants Start Going to Seed

When your plants bolt, you have two choices. You can leave the plants in your garden to give food for the pollinators and save your own seeds. Or you can remove the plants and replace them with something better suited to the current season. Let's look at each choice.

Option #1: Keep the Plants in Your Garden

There are three good reasons to keep these plants a little longer, even though you won't be able to harvest any more delicious leaves.

One: Pollinators Love the Flowers

Those pretty little flowers produce food for our bees, butterflies, and ladybugs. Bees particularly love the yellow flowers of brassicas like bolting broccoli and bolting mustards because they're fragrant and there are a lot of them. Bees can drink their fill from just one plant.

Two: The Flowers Benefit the Overall Health and Productivity of Your Garden

The many pollinators that visit your garden to feast on your bolting basil and cilantro will swing by your fruiting plants and make sure they get pollinated, as well. That means your fruiting plants will be more productive. The flowers also attract other beneficial insects like parasitic wasps that can help you control garden pests.

Three: You Can Save Seeds for Next Year

If you leave your bolting plants in the garden long enough, the flowers will dry up and the seeds will mature inside them. You can collect these seeds or let them drop into the soil so they'll sprout next year.

Just one bolting plant can produce dozens, sometimes even hundreds, of seeds. Simply by leaving a plant or two in your garden each season, you can produce seeds to last you for years and years to come. You can even share with your gardening friends. I mean, who doesn't love free seeds?

Pick your favorite plants to go to seed (maybe they were super productive or extra beautiful). Assuming the plant wasn't a hybrid, the seeds will remain true to the original plant. Even cooler, over time, you can grow plants that are better and better adapted to your unique garden space.

In some cases, the seeds from these plants are a much-loved spice. That's certainly the case for cilantro (aka coriander), and dill seeds are also edible and delicious.

How to Save Seeds from Bolting Plants

Saving seeds from plants that are no longer producing is like making lemonade when the garden gives you lemons. Pinch off the flowers of your herbs and salad greens for as long as possible so you can buy yourself a couple more leaf harvests. Then, let the plants completely go to seed toward the end of the season.

Here are guides to saving seeds:

• Bolting cilantro? You're about to get cilantro seeds, or as we call them in the kitchen, coriander! Here's how to harvest and save your own coriander.
• Bolting basil? Here's the easy way to save your own basil seeds.
• Bolting radishes? This one's particularly fun because the seeds won't actually come from the beautiful purple and white flowers but from these little bean-like seed pods. Here's how to save those radish seeds.
• Bolting lettuce? Here are the easy steps to save your own lettuce seeds.
• Bolting dill? Follow these 3 easy steps to save your own dill seeds.
• Bolting arugula? Just like with radishes, the seeds will form in little bean-like seed pods. Here's how to save arugula seeds.

Option #2: Remove the Plants & Replace Them with Something More Suited to the Current Season

If you have limited space in your garden, then you might not want to keep these rapidly expanding plants around just for their seeds, especially not if you already have flowers for the pollinators.

Before you remove a plant, harvest a couple leaves and do a quick taste test to see if you still like the flavor or texture. I keep eating the leaves of bolting plants as long as I can. They are, after all, 100 percent edible. Harvest as much from the plant as you can before you say bye bye.

To remove a bolting plant, use pruners or a hori hori knife to cut the plant's base, right above the soil line. Leave the roots in the soil so that you don't disturb neighboring plants.

Now you'll have room for this season's plants, which will thrive in your current weather conditions instead of immediately trying to produce seeds. And as long as your bolting plants weren't suffering any major pest or disease issues, you can toss them into the compost pile so that they become food for next year's plants.

Are Bolting Plants Still Edible?

Before you toss a bolting plant into the compost, consider saving those flowers. Arugula flowers, radish flowers, cilantro flowers—they're not only edible, they're actually pretty delicious. Have you heard of broccoli raab or kale raab? Those culinary treats are just yellow broccoli flowers and kale flowers! Who knew letting your plants go to seed could feel so gourmet?

I like to sauté brassica flowers with some EVOO, salt, and pepper. You can also toss them into your salad bowl (arugula flowers are great to add a peppery kick). Radish flowers (pictured below) are edible, and guess what? So are those little green seed pods forming on your radish plant. They have the same peppery flavor you'd expect from a radish, and if you pick them before they start drying out, they have a nice, crisp texture.

This is the really cool part about growing your own veggies. You get to try something new and enjoy more parts of the plant than what you see at the grocery store. Even if you're not interested in eating the flowers, they're all so pretty you could use them as garnishes.

Don't Cry Over Bolting Plants

Bolting is nothing to stress about when it comes to the garden. In fact, it's something to celebrate. Your plants have a purpose beyond what you're growing them for, and they're ready to produce flowers and then tons of seeds. You can enjoy their beautiful flowers, use them to help support our pollinators, and save seeds for yourself. And then as soon as you're ready, you can pull the plant and make room for next season's crops.

The garden is always giving, even if it's not the thing we originally wanted. Watching your plants go through their complete life cycle might just teach you a thing or two about plants and help you see them in a whole new light!