Growing Broccoli: How To Grow Tasty, Tiny “Trees”

What’s the name of Bruce Lee’s vegan brother? Brocco-Lee, of course! This veggie may not be into martial arts, but it’s definitely a master in the garden. In this article, we’ll teach you everything you need to know about growing broccoli at home.

Bad jokes aside, it isn’t hard to grow broccoli, we promise! You’ll be amazed at how well these cole crops take to your garden. Once planted, they’re low-maintenance, especially if you have an irrigation system set up. 

Unlike cauliflower, which is one and done, broccoli will continue to produce edible shoots after the main head is harvested. The leaves, opened flowers, and seeds pods are also edible, so not much will go to waste. Nutrition-wise, broccoli supplies a good amount of Vitamins A, B, C, fiber, calcium, iron, zinc, and more. What else could you ask for in a veggie?

As the icing on the cake, broccoli plants are cool-weather crops, so they’re easy to grow up north. Don’t feel left out if you live in a warm climate though – broccoli will grow during the winter there! So let’s get to know this popular veggie a bit more. After we’re done, you’ll be able to grow and eat those tiny, tree-shaped florets.

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• Monterey BT Caterpillar Killer
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• NaturesGoodGuys Beneficial Nematodes

Quick Care Guide

Common Name(s)	Broccoli
Scientific Name	Brassica oleracea (Italica Group)
Days to Harvest	100-150 days
Light	Full sun
Water	Consistent; medium
Soil	Fertile, neutral soil pH
Fertilizer	Balanced, when needed
Pests	Cabbage worms, cabbage loopers, root maggots, aphids
Diseases	Blackleg, black rot, clubroot

All About Broccoli

If you were to look up the name Brassica oleracea, you’d be bombarded with a plethora of cruciferous plants. From kale to Brussels sprouts to kohlrabi, this species encompasses many different vegetables (referred to as cole crops). To keep things orderly, B. oleracea is split into groups, which will definitely narrow your search.

The Italica group consists of the many species, including our 27 favorite types of broccoli. Here you’ll find varying flower crowns from the Broccolini hybrid to the bizarre-looking Romanesco broccoli. Sometimes it’s best to stick with the basics, though! For that, you’ll want to grow the Calabrese variety, which is the broccoli commonly found in grocery stores.

We can thank the Mediterranean and Asia Minor for broccoli. Our favorite green veggie is thought to have grown back in ancient Roman times, particularly in Italy. It wasn’t until the 1700s that this vegetable made its way to England and, a bit later, to America. Surprisingly, broccoli is only recently popular in the US, having gained its notoriety in the 1920s. 

I’m sure you’ve heard that broccoli is a flower, which is 100% correct! The head is entirely composed of tightly clustered, unopened buds that are supported by sturdy, dense stems. We aim to harvest broccoli before the flowers open. If left to their own devices though, the buds open into a loose bunch of cross-shaped, yellow flowers (hence the name Cruciferous).

The central head grows atop a cushion of big, dull-green leaves. Take one look at the foliage, and you’ll see the resemblance to cabbage. The entire plant typically reaches 1-2.5 feet tall and 1-2 feet wide. Even though it’s a perennial, broccoli is usually grown as an annual, especially in colder areas.

Planting Broccoli

Because of the way broccoli grows, the time frame is somewhat flexible. You can choose to plant broccoli for a spring harvest, fall harvest, or both! Plus, if you live in a warm climate, you can plant in the fall and harvest in the spring. The broccoli will overwinter as long as the garden temperatures aren’t consistently below freezing. 

For a spring harvest, start the broccoli seeds indoors 6-8 weeks before the last frost date (late winter to early spring). 3 weeks before that date, harden off the seedlings and plant them outdoors. You can also plant broccoli starts at that time. Your broccoli heads should be ready to harvest at the tail end of spring.

For a fall harvest, plant broccoli seeds indoors in July. Your aim is to transplant outside when the temperature is less than 75°F, so you’ll need to time this with your area’s climate. Ideally, you’ll be able to transplant to the garden in mid-August.

Plant broccoli seedlings in a space with lots of sun and fertile soil. Fall crop rotation is an excellent tool to prevent disease in cole crops, so try to plant somewhere that hasn’t grown anything cruciferous in at least 4 years. Broccoli growing is possible in containers, as long as they’re large enough (at least 8” deep and wide).

One of the best containers is right in our shop! Try the high-quality Epic Gardening grow bags. Container growing has the added benefit of being able to move your plants into the shade in times of extreme heat. And you can adequately space broccoli plants with ease.

Because they’re so small, only sow seeds a couple of centimeters deep. Space broccoli plants 18 inches apart and 2-3 feet (48-36 inches) apart. Germination takes 4-7 days and requires temperatures between 45 and 85°F. Transplants can be planted deeper than they were in the container by a few inches. Apart from a nice look, this will help create a more compact plant.

Broccoli Care

Your broccoli plant doesn’t need much work now that it’s planted. Keep up with the following care needs, and you’ll soon have a rewarding harvest.

Sun and Temperature

Broccoli needs full sun, so we’re looking at 6-8 hours of direct light per day. However, full sun paired with hot heat can do more damage than good. You may need to shade the broccoli plant if the temperature gets above 80°F. If not, the growth may be stunted, and the broccoli heads can bolt. Shade cloths are excellent for keeping vegetable plants out of the heat (look for 30% coverage).

These plants are somewhat vulnerable to frost but typically do fine if the temperature stays above 20°F. Ideally, though, the garden temperature should be 45-75°F. 

Water and Humidity

Broccoli plants love, love, love their water. They also have shallow roots, so you need to be very consistent.

Don’t let the soil dry out, or you’ll stress out the broccoli plant, which disrupts its growing and gives the vegetable a bitter flavor. Keep the soil moist. Of course, you don’t want to drown them either. There shouldn’t be puddles on the soil surface after you water. Using a soaker hose provides a great way to keep them fully hydrated.

Mulch is highly encouraged for broccoli plants. It will protect the shallow roots and help keep the water in and weeds out. Organic matter, such as compost, chopped leaves, or grass clippings, are excellent choices for your garden.

Soil

Loamy soil is best, but a variety of soil textures work as long as they have a good balance of draining and water retention to keep the soil moist. The soil will need to be consistently moist, but we never want to drown the roots (even plants need air!). The soil pH should be neutral or at a slightly acidic (6-7) soil pH.

Keep the garden soil rich with organic matter, and your broccoli plants will thank you! A good supply of nutrients will help them mature before the broccoli growing season is over. Add organic matter before planting and periodically as the plants grow.

Fertilizing

The best way to supply your broccoli plants with nutrients is to add organic matter to the soil. However, you can apply fertilizer to give your veggies an extra boost. Starting after transplanting, apply it every few weeks until harvest.

Choose a balanced fertilizer, such as 10-10-10 or 12-12-12. Slow release is often the most convenient, as it will supply nutrients for a longer period of time. To really help the broccoli plant absorb it, water in the fertilizer after applying. When applying any fertilizer, avoid letting it touch the plant to prevent burns.

Pruning

Broccoli doesn’t look like it needs it, but pruning can actually help you strategize its growth. When left to its own devices, broccoli grows a central head and some side shoots. With pruning, you can choose to focus growth on the broccoli heads or shoots.

For larger broccoli heads, clip off the side shoots whenever they show up. On the flip side, remove the central head about a month after transplanting. This will result in several medium-sized side shoots. As always, use a clean, sharp knife or sterilized pruning shears when making any incisions in your plants.

Be sure to space your broccoli at least 18 inches apart, so they don’t run into each other. If your garden does end up short on space, you’ll need to transplant the broccoli instead of pruning it.

Propagation

Since it’s usually grown as an annual, broccoli is typically only propagated by seed. Because they cross-pollinate, the plants grown from your harvested seeds may not be true to type. Nevertheless, seed-saving is a fun experiment that every gardener should try.

You’ll have to sacrifice a broccoli head by allowing it to fully mature. Choose one that’s healthy and let it bolt, which is when the head breaks apart into fluffy bunches of yellow blooms. It’s actually very wildflower-esque! After bolting, seeds start growing inside the flower stems. You’ll actually be able to see the stems round out, giving them a pea-pod appearance. This whole process will take at least a couple of months.

Once the seed pods have dried out on the plant, remove the broccoli plant from the ground and let it dry for an additional two weeks. Then, you can pluck off the seed pods and crush or twist them to release the seeds. The small, round broccoli seeds will last for up to 5 years but are best used as soon as possible. Store them in a dry, cool place until you’re ready to plant. 

Harvesting and Storing

You put in all the work to grow broccoli, and now you get to reap the rewards! The process to harvest broccoli is simple, so you’ll be munching on the florets before you know it.

Harvesting Broccoli

Harvest your broccoli sooner rather than later. You don’t want the plant to bolt! The head should be tight, stiff, and fully colored. Usually, it will be fist-sized or larger, but this varies with the variety.

Cut into the stem 4-6” below the head (or further down if you want to eat the stem as well). You can also harvest the leaves and eat them as you would collard greens. Opened flowers and seed pods can also be eaten, usually as a garnish or sprinkled in salads. You should be harvesting broccoli in the morning, when the weather is cooler, and move the heads from garden to fridge as soon as possible.

Most varieties will send out shoots after harvest, which could give you a second spring or fall crop, so leave the plant in the ground for a while after you’re done harvesting broccoli. These shoots will be smaller than the original head but are just as tasty! Make sure you leave enough stem and leaves so that the shoots can grow broccoli again.

Storing

After you’ve finished harvesting broccoli, you can store the broccoli head in the fridge, unwashed, for 3-5 days. If long-term storage is more your style, blanch and freeze the heads for up to 12 months. When blanching, you’ll want to slightly undercook them, so they don’t turn mushy when thawed. As with any vegetable, the sooner you eat it, the better the quality.

Troubleshooting

As we mentioned, broccoli growing is pretty simple. Still, you need to be aware of the potential problems that could make the process less than simple. Here’s a quick guide to what you should be on the lookout for.

Growing Problems

Bolting may be the goal when seed-saving, but it can disrupt a good harvest. When broccoli bolts, the head breaks apart and extends the blossoms. The yellow flowers may be pretty, but they aren’t ideal if you want a compact broccoli flower head.

Hot weather usually brings on bolting since it tricks the plant into thinking its broccoli growing season is over. You can prevent this by shading the plant in high heat. Unfortunately, once a plant bolts, there isn’t a way to fix it – although the flowers are edible.

Another growing problem is leggy broccoli seedlings. This happens when they don’t get enough sun – the plants literally stretch out, looking for light. Catch it early on, and you can repot the seedlings deeper to have another go at short, compact plants. Be sure to give them more light though, or you’ll just end up with the same problem. 

Pests

Cabbage worms and cabbage loopers will go after a variety of cruciferous veggies, including our beloved broccoli. They pose the biggest threat to broccoli seedlings and the flower head. These green caterpillars will chew through leaves and flowers, eventually killing the plant. You can prevent infestations by using row covers until the plant flowers. For existing populations, apply BT spray or diatomaceous earth to protect your garden.

Root maggots are just as dangerous to your garden as they are disgusting. These are fly larvae that overwinter in the soil, only to wake and get to work devouring your broccoli from the roots up. Beneficial nematodes will feed on the larvae when they’re still in the soil, along with other garden soil pests. You can also prevent the larvae by tilling the soil after harvest. Floating row covers are also great preventative measures.

It seems that no garden is a stranger to aphids. Luckily, it’s possible to keep these pests away while growing it. Insecticidal soap is an excellent remedy for aphids as well as other garden pests. You can also just hit the plant with a strong spray of water, washing off the pests. Aphids also have a number of natural predators, including ladybugs, lacewings, and frogs. Frogs also feed on cabbage worms and loopers as well, so if you’ve got those around you’re lucky!.

Broccoli Plant Diseases

The deadly blackleg disease originates in the soil and can easily pass from plant to plant. It affects seedlings the most and can be very difficult to control. With this disease, you’ll notice brown lesions that eventually turn grey and develop reddish margins. The leaves will turn yellow without falling off. Blackleg will quickly kill the plant and can’t be remedied so prevention is essential. Use crop rotation and keep the soil clean, removing dead plants immediately. After harvest each year, keep the soil dry and well-aerated.

Black rot is another dangerous disease caused by bacteria. Broccoli will begin to show symptoms in its leaves. There will be dull, yellow, V-shaped sections spread across the leaf. These sections eventually turn brown and die. The disease will spread to the stem next, effectively killing off the broccoli.

Sadly, black rot cannot be eliminated once it’s settled in. You can however, attempt to slow the spread with copper fungicide. You may be able to harvest the head and side shoots as long as you cut off any affected areas. Prevent black rot by taking care of your soil. Rotate your spring and fall crop and make sure the soil has enough nitrogen. Avoid watering with sprinklers, as they can aid in spreading bacteria.

Clubroot is yet another soil pathogen that leaves broccoli worse for the wear. It attacks the roots, causing them to swell and become deformed. Prevention is the best medicine here, so keep your soil healthy by using crop rotation and disease-free seeds and plants.

Frequently Asked Questions

Q: How long does it take to grow broccoli?

A: Most broccoli types are ready to harvest about 100 days after you sow seeds.

Q: How much broccoli do you get from one plant?

A: When growing broccoli, you’ll get one central head and possibly some smaller side shoots.

Q: Does broccoli grow back every year?

A: You can grow broccoli as a perennial, but it’s most often grown as an annual, especially in areas with cool weather.

Q: What month do you plant broccoli?

A: It’s a cool season plant, so plant it in spring and fall months when it won’t be subject to too much heat or freezing weather. It can be either a spring or fall crop.

Q: What not to plant with broccoli?

A: Broccoli is a heavy feeder, so don’t plant it with strawberries, peppers, tomatoes, corn, or cucurbits. These are also heavy feeders.

Q: Is July too late to plant broccoli?

A: In areas with a milder summer, no! However, I wouldn’t plant broccoli starts in hot summers.

Q: Are coffee grounds good for broccoli plants?

A: Try using other less stringent sources of nitrogen for your broccoli. If you have compost that’s rich with coffee grounds, that works too.

Q: How do I keep bugs out of my broccoli garden?

A: Give them a blast of water, or throw a floating row cover over your crowns to protect them.