8 Tips to Stop Vegetables From Bolting This Summer

If you’ve tried to grow cool-weather crops like cilantro or lettuce in early summer, you’ve probably run into this frustrating issue: seeing your plants bolt before they’ve even gotten started.

Certain plants are more susceptible to bolting than others, but there are ways to help your favorite plants last just a little bit longer in the garden (even if it’s the middle of July).

Bolting is sometimes also known as “going to seed” for this reason—a plant bolts as a last-ditch effort to spread its seed and produce offspring. (This is technically different from a plant naturally going to seed at the end of the growing season, after it’s put out a full harvest.)

Bolting occurs for various reasons, but it’s especially common in heat-sensitive plants like lettuce, kale, arugula, broccoli, cauliflower, cabbage, and other leafy greens. But, it can also happen early in root crops like carrots, beets, turnips, parsnips, rutabagas, and radishes in response to stress, resulting in flower spikes when the plants are barely developed.

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Direct sowing eliminates all possibility of transplant shock and allows root systems to develop without disturbance. (Just don’t forget to thin your seedlings to keep them from competing for sun and space.)

Look for seedlings that are stout and full, rather than those with tall and spindly stems. I often see brassica seedlings that are already on their way out because they’re all gangly and wiry with small, narrower-than-normal leaves that grow vertically.

If you’re transplanting your own seedlings started at home, choose the most compact, lush, and healthy-looking seedlings over larger or taller seedlings that may be pale or rootbound.

Cool-season crops (like carrots and cabbage) are best planted in early spring or late summer so they mature while temperatures are still mild. Not only that, but these types of crops actually turn sweeter if they mature in cold weather! If you’ve never tried growing root crops or leafy greens in fall—and harvested them after the first frost—you’re in for a treat.

If you live in an area where warm weather comes quickly in spring, consider growing an early-maturing variety or start your seeds in late winter so you can transplant sooner.

Or, start a fall garden when hot weather and day length (the main causes of bolting) won’t be issues at all. You can start seeds in mid to late summer, or transplant seedlings in early fall when the soil is still warm. (Though if your climate sees some of its hottest days in September, here are a few tips for planting a fall garden in the heat.)

Read next: The fastest-growing crops you can plant and harvest in 40 days or less

A 2-inch layer of organic mulch helps insulate plant roots and keep them cool in hot weather. This reduces the amount of heat stress a plant experiences when air and soil temperatures rise, and prolongs the harvest period.

A long, slow watering also encourages roots to penetrate deep into the soil, where they have access to more moisture, nutrients, and beneficial microbes.

Read more: How to water your garden properly during a heat wave

On particularly hot days, I’ll often give a supplemental watering (on top of the drip irrigation in my garden beds) to give some midday relief to heat-sensitive plants.

You can also plant in the shade of taller crops, or plant in containers so you can move cool-season crops to shadier spots in the afternoon.

Seaweed extracts also contain many active compounds and trace minerals that help promote growth in plants by developing stronger root systems, increasing yields, and improving resistance to pests and diseases.

What all of this means is that using an organic seaweed or kelp liquid fertilizer can not only help your plants grow bigger, but also help them withstand extreme heat and recover from environmental stresses.

Note that you should never fertilize plants while they’re under heat stress—doing so may damage plant tissues and cause even more stress.

An interesting “exception” to this rule are herbs like parsley and cilantro, which actually become more productive if you snip off their flowers (and stems) and harvest them frequently. Doing so can extend their life cycle by many months with no perceptible change in flavor or texture.

For the majority of vegetable crops, however, they’ll continue to send up new flower spikes and slow down vegetative growth, even if you remove all their flowers.

For one thing, some flower buds (like kale) are edible and even considered a delicacy. You might not be able to get a full harvest of leaves, but you can certainly get a few handfuls of flowers to toss into a salad or stir-fry!

Secondly, bolted plants in the brassica family (such as broccoli, kohlrabi, kale, and collard greens) and parsley family (such as parsley, cilantro, fennel, and dill) are a pollinator’s paradise.

Bees absolutely love these small, simple flowers (which tend to grow in clusters called umbels), and I’ll say that I tend to see more bees on my flowering mustards and flowering herbs than I see on the blooms in my flower garden.

Learn more: My favorite bee-friendly flowers to plant in every garden

But it’s not just about the bees—other beneficial insects and predatory bugs also feed on nectar and pollen. Making these florets available ensures that they stick around in the garden, thus helping you control pests naturally.

Make this: Attract good insects to your garden with these simple recipes for beneficial “bug chow”

And lastly, bolted plants give you an opportunity to save seeds. Most people never save seeds from carrots, beets, kale, or collard greens because—as biennial plants—they’re often harvested before they complete their life cycle.

But if they bolt, you can save seeds from your favorite varieties without waiting for them to go through two growing seasons.

This post updated from an article that originally appeared on June 29, 2023.