If you’re wondering how to grow broccoli, this guide will give you all the tips and tricks for a successful broccoli harvest. Broccoli is one of my favorite cool season plants- perfect for early spring or a late fall crop.

How to Grow Broccoli from Seed to Harvest

This post on how to grow broccoli is part of my how to grow garden vegetable series. Read all the tutorials for ultimate gardening success!

If you know that broccoli is actually a flower? The florets are actually buds that turn into pretty bright yellow flowers if you don’t cut it in time. The flowers will grow about 7 inches tall up from the buds and I love to include them in flower arrangements from time to time. 

Some people wonder if you can still eat broccoli after it flowers – and you can! One of my favorite things about broccoli are the abundant and edible side shoots it will continue to produce for a long harvest.

When to Plant Broccoli

Broccoli is a cool weather plant that likes the sunshine. It likes spring and fall but doesn’t like summer heat. You’ll want to start seeds 12 weeks before the last spring frost date. 

In my Iowa zone 5 garden, broccoli can be planted in April if the long term forecast looks warm. Just make sure to keep an eye out for any hard frosts and cover with a fleece blanket or row cover if the temperatures dip.

A general answer for the question of when to plant broccoli is to plant seedlings two weeks before your last frost. If you don’t know your last frost date, make sure to find that out by clicking here.

If you want to grow a fall crop of broccoli, plant it after the heat of summer has died down and keep those frost blankets or row covers handy to protect it from early fall frosts.

How to Plant Broccoli

If you’re starting seeds indoors, sow seeds in potting soil and sprinkle lightly with more in each tray spot 12 weeks before your last spring frost. Seeds will sprout in 5-10 days. Keep them warm on a heat mat until you see most have sprouted and move to full sun. 

Plant broccoli seedlings outside in the garden after hardening off 5 weeks before the last spring frost. Broccoli plants grow quite large, so space them 15 to 18 inches apart to give them plenty of room.

Read my post on starting brassicas from seed here.

Be sure to water regularly and often.  Don’t forget that the part we eat is a flower head so an organic fertilizer for blooms will be good.  You’ll also want to make sure to mulch to keep weeds down and moisture in.

Common Pests and How to Protect Broccoli Against Them

Broccoli pests to watch for are cabbage loopers (little green worms like love all brassicas), cutworms, and root maggots. Cabbage worms can be easily controlled two ways:

1. Using row covers
2. Or spraying Bt

Bt (Bacillus thuringiensis) is an organic approved pesticide that will also take care of the invasive caterpillars and the cutworms.

You can hang pheromone traps to collect the adult cabbage worm moth and prevent them from laying their yellow eggs. 

Root maggots can be controlled by diatomaceous earth and row covers.  Be sure to sprinkle it regularly and after any rains.

Companion Plants for Broccoli

I highly recommend using companion plants for the benefit of pollinators as well as all plants in your garden. The right companion plants can attract helpful bugs to keep bad bugs at bay and can also enhance the taste and performance of your veggies. Good companion plants for broccoli include:

• Other veggies: onions, potatoes, beets, radish
• Flowers: nasturtiums, marigolds, tansy 
• Herbs: rosemary, dill, basil, mint

There are also a few plants you might want to avoid planting near broccoli:

• Nightshade plants (tomatoes, peppers, eggplant)
• Beans
• Strawberries

When & How to Harvest broccoli

Harvest when the broccoli head looks tight by cutting the main head at the base with clippers or a sharp knife.  You can then harvest multiple side shoots in a few weeks.

When in doubt remember it is better to cut sooner rather than later. You’ll want to quickly remove any flowering shoots to encourage the plant to continue producing side shoots.

How to Preserve Broccoli

Broccoli can be preserved by canning, drying, freezing or fermenting.  We prefer to freeze broccoli and add it to soups.  I like to dry or freeze the stems, then blend them in smoothies and veggie soups. 

Here are a few of my favorite ways to eat broccoli:

Beef and Broccoli Instant Pot Recipe

Tossed Salad with Broccoli, Feta, & Sunflower Seeds

Did you know that a head of broccoli was a flower? Any questions about growing broccoli in your backyard garden?