Grow Your Own Broccoli Plant
When I was writing my second book, Leaves, Roots, and Fruit, I organized all the edible plants into nice, tidy categories: herbs, leafy greens, roots, bulbs, tubers, small fruit, large fruit, and seeds. But wait a second, I realized. What about broccoli?
Broccoli and cauliflower are the oddballs of the vegetable garden. That's because we don't grow them for their leaves (though those are edible), their roots, or their fruit. The part that we eat is actually the unopened flower head!
I ended up lumping broccoli and cauliflower in with large fruit because they take a lot of space and time to produce. Like these large fruiting plants, broccoli can actually be pretty tricky to grow, so make sure you follow this guide to plant and grow broccoli at home.
The Two Types of Broccoli to Grow in Your Garden
There are two types of broccoli, heading and sprouting. Both are vegetables that have edible flowers (and leaves) that we can enjoy.
Heading Broccoli
Heading broccoli is the variety most familiar to those of us in the United States. The head of broccoli is actually the plant's buds. Left intact with the roots, these buds open to reveal small yellow flowers. We typically pick these flower buds before they open, when they're still green or purple, and enjoy them raw or cooked.
Sprouting Broccoli
Sprouting broccoli has a similar taste but grows dense purple or white heads, rather than the green heads we're used to at the grocery store. The white heads can look similar to cauliflower. The florets of sprouting broccoli are typically a bit smaller, as well.
My Favorite Broccoli Varieties to Grow
There are many fun broccoli varieties to try growing at home that you won't find at the grocery store.
Calabrese broccoli is the traditional variety. Then there's Chinese broccoli, also known as gai lan, kai lan, or Chinese kale. Bimi broccoli is a new super vegetable that's actually a fun cross between broccoli and a leafy green from China. There's also tenderstem broccoli, or broccolini.
Romanesco broccoli (pictured below) is a variety of broccoli created from the union of traditional broccoli and cauliflower. If you're into fractals, give this one a try.
Purple broccoli, AKA broccoli of Sicily, is very similar to common broccoli, except that the heads have a purple color and are smaller, but its flavor is the same as that of traditional broccoli.
Broccoli Growing Guide
When to Grow Broccoli
Broccoli loves cooler temperatures between 50 and 70°F. It can withstand frost, but it does not like warm weather, especially not when it's trying to produce a head. While broccoli seeds will germinate in temperatures as low as 40°F, the process may take two or three times as long, depending on the variety.
This temperature preference might not sound like much, but it's one of the main reasons why broccoli can be so hard to grow (and why 90% of the broccoli you find at the grocery store is grown in just one place, California).
Here's the thing: Broccoli requires at least 60 days (sometimes as many as 100) of temps between 45 and 80°F to complete its growth. Figuring out your best broccoli growing window is the tricky part.
I've tried to grow broccoli in several different climates. I'd plant out my little broccoli seedlings as soon as my soil was workable in the spring, but I'd always face the same issue. The spring temps were warming up too fast and reaching 85°F during the day. The little florets would start opening up in the heat before I'd ever get a broccoli head.
I finally decided to try growing broccoli in the fall, and that works much better for me. That means starting broccoli seeds indoors around July and planting broccoli in the late summer, around September, for me here in Nashville. I recommend starting your seeds indoors about 90 to 100 days before your first frost and then planting your seedlings outdoors about 60 days before. Your plants will put on lots of leaves as the days grow cooler, and then you'll be able to harvest a nice, compact broccoli head just before the cold of winter really sets in.
If you have a really long spring with a good stretch of 90 days between when your soil is workable and when your temps finally reach the 80s, then you're good to grow spring broccoli.
Alternative: Grow Broccoli Microgreens Year Round
If growing your own broccoli is already sounding like a lot of trouble to you, there's another option. Actually 2 other options.
Broccoli sprouts and broccoli microgreens are super healthy and can be grown indoors in a matter of weeks, if not days, with very little setup required.
Broccoli makes for a great vegetable to grow as a microgreen because the entire plant is edible, even if consumed raw. Plus, you get all the nutrition of a full-grown broccoli head without the long wait.
Where to Grow Broccoli
These plants need a lot of space. I typically give them at least 2 square feet for them to spread out. I have a lot of clients who love to grow broccoli in their raised beds, but these plants take up too much of that precious raised bed real estate for me. I prefer to grow broccoli in the ground or in a large container on its own.
To grow broccoli in the ground, amend your native soil with some compost first. I've found that broccoli grows really well right alongside my native plants and pollinator-friendly flowers in the ground.
You can also grow broccoli in containers at least 18" deep and wide. Make sure your container has at least one good drainage hole in the bottom. I bought 4 of those big whiskey barrels from Home Depot and added drainage holes; I grow potatoes in them from about March to August and then turn them over to my broccoli in the fall.
Sunlight
Broccoli needs 6 to 8 hours of sunlight to form a nice head.
If your cool season falls during the short days of winter, this makes meeting broccoli's ideal growing conditions difficult. Winter sun is very different from summer sun, and spaces that receive lots of summer sun all day long might struggle for enough winter sun. Ideally, broccoli should be planted in a southern-facing location away from any large structures that might block winter sun.
The Best Broccoli Companion Plants
Avoid planting broccoli with other vegetables in the brassica family, as they may attract more of the same pests. Broccoli also tends to hog all the nutrients, leaving plants like kale and collards with not much to grow on. It's important to plant broccoli next to plants that don't mind shade.
Some plants actually help improve the flavor of broccoli when planted nearby:
- Celery
- Onions
Other plants with really strong scents help to repel common garden pests that feed on broccoli:
How to Start Broccoli Plants
Because broccoli takes at least 60 days to grow from seed until it's ready to harvest, I recommend starting broccoli by seeds indoors at least 30 days before transplanting. Make sure to harden off your broccoli seedlings before moving them permanently to the garden space.
If you're not up for seed starting, then you can simply purchase plant starts from a local nursery or farmers' market.
Transplant your broccoli plants to the garden once the temperature is ideal. Space each plant 2 to 3 feet apart in rows if you're growing in the ground. Cover your plants with a floating row cover or garden mesh just after planting to prevent caterpillars.
Water in plants well and keep the soil consistently moist for the first 2 weeks after planting.
How to Care for Broccoli Plants
While you wait for the plant to grow, these are your main tending tasks:
Feed
Broccoli is a heavy feeder. Fertilize three weeks after transplanting with some fresh organic compost. Repeat every couple of weeks.
Water
Provide consistent soil moisture with regular watering, especially if you're not getting much rain, since the roots of broccoli plants are pretty shallow. When you water, avoid getting developing broccoli heads wet. It's best to aim your water at the roots, not the leaves.
Support
Once broccoli has developed its first few sets of leaves, it can benefit from hilling. This is when you add fresh compost around its base. Broccoli can become a little top-heavy as it grows. If needed, use a stake and some twine to support your growing broccoli plant.
Prune
Prune back excess broccoli leaves and make sure that each plant is getting good airflow by keeping a good distance from neighbors. If you're growing broccoli in a raised bed, it's really important to prune those lower leaves often so that all your other plants still have room to grow.
You know those broccoli leaves that you cut? They're edible and can be eaten raw or cooked.
How Broccoli Grows
Broccoli forms a tighter and tighter flower cluster, swelling larger and growing daily. While this happens over a period of weeks, you can actually harvest at any point. The trick is waiting long enough to get a good harvest but not too long—otherwise, the broccoli florets will turn yellow and burst into flower.
If your broccoli bolts, or flowers, before you can harvest it, don't worry. The plant is still edible. The flavor, however, might change a bit.
Common Broccoli Growing Problems
I like to say broccoli and cauliflower are not for beginners. They're too picky about their growing conditions to make things easy on gardeners, and as you can see from the host of problems below, many things can go wrong during the long time broccoli will spend in your garden growing.
Here are common problems and how to prevent or solve them.
Problem: Broccoli turning yellow
If the bottom leaves turn yellow and the problem continues toward the top of the plant, then your broccoli plant is suffering from nitrogen deficiency.
Solution
Give your plant a high nitrogen (but low phosphorus) fertilizer or blood meal. Blood meal is a quick nitrogen fix for yellowing leaves.
Problem: Broccoli worms eating leaves
If you've ever checked on your garden and wondered why there are holes in your broccoli plant's leaves, you've got broccoli worms or caterpillars, most likely cabbage loopers or cabbageworms. You'll know there's a pest issue if you see small holes on the leaves between the veins.
Solution
Look on the underside of the leaves for small green caterpillars, and pick them off by hand if the problem is small. If it's out of control, use Bt (Bacillus thuringiensis), a natural bacterial pesticide. Again, cover your plants just after planting with garden mesh to deter caterpillars.
One good thing about growing broccoli in the fall is that the pests will stop bugging you once you hit your first frost of the season.
Problem: Broccoli leaves wilting
If your plants are wilting suddenly, it may be due to a fungus called clubroot in the soil. The entire plant, including all roots and root tendrils, must be gently dug up and removed. If the roots are gnarled and misshapen, then clubroot is for sure the problem.
Solution
Act quickly to remove the affected plants so that the fungus doesn’t continue to live in the soil. Do not compost the plants. Raise the pH of your soil to above 7.2. You may need to sterilize your soil too.
Problem: Yellow patches appearing on broccoli leaves
This is typically a sign that moist weather has caused downy mildew.
Solution
Keep leaves as dry as possible with good air circulation. Buy resistant varieties.
Problem: Broccoli leaves curling
Curling leaves are often a sign that the plant's sap is being sucked by insects, typically aphids.
Solution
Apply soapy water to all sides of leaves whenever you see aphids.
How to Harvest Broccoli
Another great reason to grow broccoli in the fall/winter is because the heads are actually better if picked after the first frost of the season.
To harvest broccoli, use a clean pair of pruners or a sharp knife to cut the base of the floret. Leave the rest of the plant to keep growing. Broccoli plants produce only one main stem with a center head, but some varieties will produce side shoots, which are much smaller heads of broccoli that form along the sides of the plant. Once you cut the main head, your plant might continue to produce side shoots for several weeks, if weather conditions remain optimal.
Broccoli can stay in the humid produce drawer of your fridge for 10-14 days. For longer-term storage, it can be blanched and frozen for up to one year.
Remember that you can harvest the broccoli leaves whenever you like. You can cook these leaves just like you would kale or cabbage. They're super good for you!
Time to Grow Some Broccoli!
I hope this guide helps you figure out how to grow this tricky veggie. If you get the timing wrong and end up with a lot of broccoli flowers, the bees will at least be thrilled. Keep the plants in your garden so the pollinators can enjoy the beautiful yellow blossoms. Or harvest the blossoms because guess what? They're also edible! When life gives you lemons... you know?
Thanks for bringing back the kitchen garden with me, whether you're growing broccoli sprouts or whole heads!
