Is Broccoli a Fruit? A Flower? What Is It?

When it came time to categorize broccoli as a leafy green, root crop, or fruiting plant for my new book, Leaves, Roots & Fruit, I lumped broccoli in with large fruiting plants like melons and eggplant. I'm sure this decision left many a technical gardener out there scratching their heads or perhaps even shaking their fingers at me.

Here's the thing: If we’re talking plant parts, broccoli is technically a flower bud, not a fruit. That being said, it takes a similar length of time to develop and shares the same space and tending needs as larger fruiting plants. So from a gardening perspective, it's helpful to think of broccoli as a large fruiting plant. From a botanical perspective, broccoli is a flower bud.

So Broccoli Is a Flower?

Broccoli, cauliflower, romanesco, and Brussels sprouts are all immature flower heads. Technically speaking, the part of broccoli plants we typically consume is an inflorescence, or a head made up of the upper stems and florets. If you leave the broccoli head on the plant long enough, each floret will turn from a little green bud into a beautiful and fragrant yellow flower.

So broccoli isn't quite a flower. It's actually thousands of tiny flowers. The green heads you see at the store have all been harvested before they begin to open, and that's usually the goal when you're growing your own broccoli, as well.

Let's look at broccoli plant stages to understand more about how we go from a tight green head to a bursting yellow bouquet.

Broccoli Plant Stages

Broccoli Leaves

Broccoli plants grow leaves and a strong main stem before they ever think about forming a flower head. Both the leaves and the stems are edible at any stage. Broccoli actually makes a great microgreen to grow for gardeners who don't have the right weather (or patience) for growing large broccoli plants.

Broccoli Heads

Once the little flower cluster forms, it'll swell larger and larger each day for weeks. It can be harvested at any point. The trick is waiting long enough to get a good harvest but not too long, or the florets will quickly turn yellow and burst into flower.

Broccoli Flower Clusters

Once the flowers begin to open, the plant will send up stalks that are typically about 4 to 5 feet tall. In the picture below, you can see the flowers at different stages of bloom and how there's no longer one central head.

The leaves, stems, and even flowers of the plant are still edible. The flowers are actually pretty tasty, but they're obviously not that tight head of broccoli you're used to.

Broccoli Seeds

If the yellow flowers are pollinated, they can produce broccoli seeds. The petals will fall off and be replaced by these skinny tendrils, which will fill out over time and eventually contain seeds that can be collected and stored for next year.

What Happens If Broccoli Flowers Before It Forms a Full Head?

This is, unfortunately, a common issue growing broccoli.

Broccoli loves cool weather, like between 45 and 75 degrees. While broccoli can handle a little frost, it does not like warm weather at all. If you have broccoli plants in your garden when the weather is warming up, the little florets might begin to open up even before the head has reached its mature size.

Obviously, you'd prefer to have a nice, large head of broccoli with lots of tightly packed and closed florets. But your preferences don't matter. Your plant is on a mission: The warming weather has stressed it out, and now it only cares about producing seeds before its time in the garden is done.

There are a couple of things you can do to prevent broccoli from flowering before the heads are mature.

Grow Broccoli in Cool Weather

Broccoli needs a 90- to 100-day stretch of weather where the temperatures are below 75 degrees Fahrenheit. It's a good idea to give yourself a head start by starting broccoli seeds indoors before the soil is even warm enough to plant in. Broccoli seedlings will need about 30 days inside before they can be moved outdoors.

Toward the end of the season, unexpected warm weather can cause broccoli to flower. The higher the temperature, the faster broccoli will bolt, or go to seed. You can use shade cloth to delay bolting by a couple of weeks.

Give Broccoli Plenty of Space

Besides rising temperatures, not giving broccoli enough space can also cause it to flower early. This is a large plant. Make sure to give it at least two square feet to spread out.

Harvest the Broccoli Leaves and Flowers

Broccoli leaves can be cooked the same way you'd cook cabbage, Swiss chard, and kale.

You might be surprised to learn you can also eat the broccoli flowers once they've opened up. Broccoli raabs are the little flowering tops of broccoli, and they're considered a culinary treat! You can sauté them with some EVOO, salt, and pepper; eat them raw; or toss them into your next stew.

It doesn't matter which plant part you're eating—this is still a super healthy veggie.

Harvest the Main Head

If your main head is flowering early, don't remove the plant from your garden just yet. Cut just below the main head and leave the plant to keep on growing. If the weather is ideal, it might produce side shoots, which are smaller heads of broccoli, so you can get a second harvest.

Let the Pollinators Enjoy the Flowers

If you're growing several broccoli plants, leave one to flower as a treat for your neighborhood bees and butterflies. Bees go nuts for the yellow blooms, which are full of nectar for them.

If the blooms are pollinated, then, of course, you can also wait a couple weeks and collect your own broccoli seeds for next year.

When Life Gives You Broccoli Flowers...

Save seeds for next year!

Even if you don't want to save your own broccoli seeds or just learn more about the life cycle of this plant, you can still enjoy the pretty yellow blooms and all the pollinators they bring in. We might not go around giving each other bouquets of broccoli, but honestly, we could.

The garden always gives you something, even if it’s not the thing you originally wanted. Thanks for being here!