The Best Broccoli Plant Spacing for High Yields

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Broccoli plants like to spread out in the garden, so it’s important to get broccoli plant spacing right. This cool-season annual vegetable yields one main head and, often, several smaller side shoots. But it’s the large leaves that grow around the broccoli head that make it possible for the plant to photosynthesize and grow. The broccoli plant leaves are kind of like solar panels for the broccoli head, and they need space to access the sun. This is a primary reason you should pay attention to where you place your seedlings.

I realize that most gardeners don’t have all the room in the world to grow as much big, widely spaced broccoli as they want, so in this article, I’ll explain broccoli plant spacing for row gardens, raised beds, intensive plantings, and mixed plantings. I’ll also share how proper spacing can minimize insect damage to this nutritional powerhouse (fiber, vitamin, and mineral content), as well as some additional space-related broccoli-growing tips.

Why broccoli plant spacing matters

It sure would be easier to densely seed broccoli seeds and let them sort out their own space, water, and nutrients; but for yield, plant health, and your garden’s organization, that’s not how these large plants operate. Broccoli plant spacing matters because:

Broccoli’s large foliage will shade out weeds around the plant. Properly spaced, the leaves create a canopy to reduce weed pressure.
Plants placed too close together can become stressed, which makes them more susceptible to insects and disease.
The size of the main broccoli head and the likelihood of side-shoot development is partially dictated by the plant’s spacing.
Broccoli requires a lot of water: one to two inches per week (2.5 to 5 cm). Competition for water will require plants to put their energy into developing root systems rather than broccoli heads.
As I mentioned above, the broccoli leaves need to have access to the sun so they can do the work of photosynthesis.

broccoli plants in a raised bed — Be sure to water broccoli plants regularly, so the plants focus on producing broccoli heads rather than putting down more roots.

Choosing broccoli varieties

Broccoli plant spacing is related to all parts of the plant’s growth, from water to nutrients, weeds, and weather. When selecting broccoli varieties, carefully choose those that match your broccoli plant spacing needs.

Look to a variety like Belstar if you have a lot of space to work with. That same variety would be inappropriate in a small garden or intensive planting. For more compact broccoli, consider DiCiccio, which grows small heads as well as abundant side shoots.

The best broccoli plant spacing for row gardens

In traditional row gardens, where you’re looking for big broccoli plants and aren’t concerned with saving space, seed or transplant 18 to 24 inches (46 to 61 cm) apart, with seeds 1/4 to 1/2 inch deep (.5 to 1 cm). Make your rows 36 inches (91 cm) apart. This broccoli plant spacing offers plenty of room for plants to spread out, reduce plant stress, and lessen competition for resources like water, nutrients, and sunlight.

Broccoli plant spacing for raised bed growing

In your raised-bed garden, look to a block-planting plan. Space three broccoli plants across a 4-foot-wide block. Make the rows 18 inches (46 cm) apart. Allow the broccoli plants on the ends of the rows to grow over the side so the plant in the middle has more space. This makes up for the tighter between-row spacing.

A block planting plan is a good idea for spacing out broccoli seedlings in a raised bed.

How far apart to plant broccoli for intensive planting plans

Because plants are resilient and have a strong will to produce, broccoli plants will grow even when given a smaller space. The broccoli heads that result may not be as large, and you may miss out on side shoots, but you can still grow broccoli in an intensive planting arrangement. Looking to the Square Foot Gardening method of planting, give one broccoli plant 12 inches by 12 inches (30 by 30 cm) of growing space. If possible, plant the broccoli on the edge of the bed so it’s less likely to shade out other plants and can take advantage of the space outside the bed or container.

If you want to talk about truly intensive planting, consider growing Jessica’s tips for growing broccoli microgreens or broccoli shoots.

Using broccoli in mixed plantings

Mixed plantings can take the shape of an ornamental-edible garden, companion plants, and other creative garden styles. Broccoli’s big, bold, deep-green foliage makes an interesting addition to a landscape. Because they can tolerate frosts and even a moderate freeze, broccoli plants add greenery during seasons when many ornamentals are going dormant. When transplanted into a mixed planting in the fall, this plant will grow and overtake the fading plants around it.

broccoli and dill in a garden — When deciding what to plant around broccoli, consider crops that will be harvested before the heads mature.

Broccoli is slower growing than lettuce and annual herbs, like dill and cilantro, so you can often seed broccoli alongside these crops. When you harvest the lettuce and herbs, you’re making room for the broccoli plant to take over the space.

How broccoli plant spacing impacts pest damage

It’s rare that you’ll have a garden season with no signs of pests. One way to reduce pest damage is to keep plants healthy, because pests will target weaker plants first. Here’s another area where broccoli plant spacing is important: Proper spacing promotes healthier plants.

There are several insect pests that love broccoli (and its close brassica relatives: Brussels sprouts, cauliflower, turnips, and kale):

Aphids
Cabbage loopers
Cabbage worms (aka green worms)
Flea beetles
Slugs
Snails

Healthy transplants are your first line of defense, and then it’s up to you to create the conditions for broccoli’s best growth with the right care. If you see too much damage or more loopers caterpillars and white butterflies than you can dispatch by hand, you may need to consider other controls.

broccoli, lettuce and peas in a raised bed — Do a soil test before planting broccoli so you can add compost, the necessary minerals, and other nutrients before planting.

Extra tips for successful broccoli plant spacing

Regardless of the spacing and plant size, remember that broccoli plants like water—especially when they’ve first getting established and when they’re forming their heads. Give them 1 to 2 inches (2.5 to 5 cm) of water each week during these times, preferably spread out every few days.

Be sure the soil has enough nutrients for the broccoli you’re planting. Broccoli is what’s known as a “heavy feeder,” meaning it requires a lot of nutrients to grow well. Amend your garden with compost before planting broccoli seedlings. Side dress the plants with a high-nitrogen fertilizer a few weeks after planting to give them a boost.

While broccoli’s big leaves will eventually shade out the weeds trying to grow around it, broccoli starts out as small seedlings, and these need protection from weeds.

leafy broccoli plants — Use caution if weeding with tools, as broccoli plants are shallow rooted. Use mulch to both conserve soil moisture and reduce weed pressure.

The warmer the weather, the more space broccoli needs to grow. Plant your broccoli at the right time of year. Broccoli plants thrive in 65 to 75°F (18 to 24°C), meaning you should plan to be ready to harvest broccoli before the weather turns hot.

Plant your early spring crop two to three weeks before the last frost date—though you’ll want to protect them from a heavy freeze when they’re young and stems are still tender. For a fall harvest, plan for broccoli head maturity a few weeks after the first fall frost. Under weather stress, the tight flower buds can quickly give way to yellow flowers, signaling your broccoli has bolted, and you’re too late to harvest. You will get the best flavor by planting in cooler weather, too.

In row gardens, raised beds, intensive plantings, and creative landscapes, broccoli has its place. Broccoli plant spacing is easier to get right when you factor in your garden type, broccoli variety selection, and its nutrient and water needs. As you’re thinking about what to plant next, I hope this article helps assure you that there’s always room for broccoli.