Growing Broccoli

If like me, you live in an area with intense summer heat, growing broccoli can be a bit challenging. Broccoli is a “cool season” crop that just gives up the ghost when it gets hot (like me!). As soon as the weather gets warm, broccoli will “bolt”, or send up lots of little flower stalks and go to seed. So if you have hot summers, either grow broccoli as a very early spring crop, or as a late-summer planting for a fall crop.

A Young Broccoli Just Starting to Develop

I like growing broccoli as a fall crop, because it takes the pressure off. In the spring, I always feel squeezed to get the soil prepared as soon as possible, get the cabbage family crops in, and then hope we have enough time before it gets too hot to get a crop.

In the fall, we usually have what folks around here call “Indian summer” – a relatively warm period after the first fall frost – which is just right for growing broccoli. It’s not too hot, the season is winding down, and there will be plenty of time for the broccoli to grow and yield before the really hard freezes end your broccoli harvest.

I start seeds in flats for my fall crop about 10 weeks before the first fall frost date. If you’re new to an area and don’t know when that is, check with your state extension service.

The Four Types of Broccoli

There are 4 main types of broccoli, and each type comes in numerous varieties or “cultivars”. By growing broccoli of different types and varieties you can optimize the amount of broccoli you can harvest in a growing year. Browse the seed catalogs for descriptions of time-to-maturity of the different varieties. I like to plant a shorter-season variety (like one of the sprouting types) in the spring, and plant the big heading ones in the late summer for a fall crop.

Big Head Todd (Really called Heading Broccoli) Big Head Todd is how I refer to the traditional, big-head broccoli type, that produces one major broccoli head at the center of the plant, and then more smaller ones after the first is harvested. This is like the kind you buy at the grocery store, although homegrown broccoli tastes much better and is more tender.

Romanesco This is my personal fave, because I can get lost in the gorgeous fractals that spin off the center. Growing broccoli of the romanesco type gives me a sense that God has a sense of humor. And each individual floret contains its own fractal, and inside each of them are even tinier fractals. Romanesco tastes less green than a Big Head Todd type, sort of like a cross between a cauliflower and a traditional broccoli (also both fractals if you study them closely).

Sprouting This type is generally shorter-season, making it a good choice for the short-spring, hot-summer growing areas. It doesn’t make one big head, it makes lots of little ones, which taste just as good and are excellent in stir-fries.

Broccoli Raab My friend Rob, a waiter, somehow acquired this as a nickname (“raab” is pronounced “Rob”), when broccoli raab became a restaurant-trendy variety and buzzword. At any rate, it’s a different species with a different taste - spicier and stronger flavored - and is harvested as asparagus-like shoots when it is very young. Because of this it is also suitable as a short-spring variety.

Broccoli Sprouts Not a type, but like alfalfa sprouts, some seed companies now sell large packets of broccoli seeds to sprout in jars for eating fresh in salads or tossed into stir fries. They are amazingly nutritious, not only in terms of vitamins and minerals, but in terms of anti-cancer, anti-inflammatory, and anti-oxidant compounds. Actually, all broccoli has these, but in sprouts they are more concentrated, and you can enjoy growing broccoli sprouts year-round in a jar on your kitchen counter. For the absolute most bang-for-the-nutritional-buck, grow broccoli seeds as microgreens. They are the world's best source of sulforafane, a potent longevity compound.

Soil and Cultivation Conditions for Growing Broccoli

All the mineral nutrition packed into broccoli comes from the soil, which means it is a heavy feeder, particularly of nitrogen. Dig in as much rich, diverse, homemade compost as you can when preparing the growing bed. If you don't have homemade compost, buy a bag at your local garden center (and start your own compost pile so you have some next year!)

Since growing broccoli needs a lot of nitrogen, it's also a good idea to amend your soil with a high-nitrogen organic fertilizer like blood meal or well-rotted poultry manure. But never use fresh poultry manure directly on the garden because it is very high nitrogen and is so concentrated it will “burn” plants. Mix it with a bit of straw or dried leaves and compost it first.

If you plan far enough ahead, you can also plant broccoli after a crop of beans, because beans add nitrogen to the soil.

Broccoli Pests

Before listing all the creatures that love broccoli even more than you do, let me give you the link to Controlling Garden Pests Naturally, so that you will have some hope!

Being a cabbage-family crop, broccoli attracts all the same pests that plague cabbage, collards, and turnips, which include:

Aphids Tiny gray, white, or even black sucking insects, that reproduce very quickly through “parthenogenesis”, meaning they can give birth to live young without mating. They can quickly cover any cabbage family crop, and seem most attracted when the plant is old and starting to bolt.

Cabbage Fly/Cabbage Root Maggot The fly is gray and tiny, and lays eggs at the base of the plant which hatch into larva about 1/3” long, and which burrow down into the soil. They can destroy a broccoli root amazingly fast, causing the whole plant to droop and die.

Cabbage Worms Really cabbage moth larva. There are several different moths that lay eggs on broccoli, which hatch into caterpillars (“worms”) that eat giant holes in leaves. The moths are grey-brown, and different species have different markings.

Flea Beetles (mostly a problem when seedlings are very little) Very tiny, shiny beetles that attack baby broccolis and collards, causing tiny shotgun holes all over the leaves.

Cabbage Looper Another larva of a moth, you can tell cabbage loopers by the way they do the “inchworm” thing, looping the body up and down as they inch along chomping though broccoli leaves.

Small White Butterfly Larva (Imported Cabbage Worm) “Small white butterfly” is actually the name of the critter, not just a description. These are not native to the US, but they’re here now. I was always told these were “cabbage moths”, but they’re not moths, they’re actually rather pretty white butterflies. Like other larva, they chomp away at broccoli.

Slugs and Snails Every gardener knows them well.

There are so many moths, larva and slugs that love broccoli... (sigh). The best control for all of them is to prevent them from reaching your plants in the first place. That means growing broccoli under Reemay or another brand of spun polyester floating row cover, available from any garden center.

Reemay is very porous so water and air can get in, but not moths, butterflies, slugs or aphids. Tack the edges down all the way around the garden bed with smooth river rocks, 2x4s, or whatever you can come up with. You can also put soil on the edges, but this is harder to move if you want to peek underneath.

Leave the Reemay loose enough, using an over-wide piece, so that the growing broccoli plants can grow to full size right underneath it.