Beyond Broccoli Part Six: Flowers, Bud!

Welcome back to Beyond Broccoli (earlier parts here) where  in this final edition we will finally get around to talking about broccoli (and its flowering friends).

Imagine you’re strolling through your vegetable garden in June (maybe a warmer June than we just had) and you notice that a lot of the brassica crops you planted in the spring look like this:

In fact, they are bolting. It’s a response to heat and other stresses; the plant will go to flower and then (assuming the flowers are successfully pollinated) will produce seed. Reproduction means, for the plant, that it’s been successful and can die happy. Of course for the gardener it doesn’t always mean success. We might have wanted that mizuna to produce lots more edible leaves before bolting. But before you yank out the plant and toss it on the compost pile, do me a favor. Snip off that little cluster of flower buds and eat it.

Yummy, right? Probably a bit spicy and a great addition to a salad or stir-fry. I have been asked so many times whether it’s okay to eat “that broccoli thing” that appears when brassicas bolt—and yes, it’s fine. It is, in fact, essentially the same thing as broccoli; it’s just that broccoli was bred from wild brassicas to produce a much larger and tighter flower bud cluster with thick stems, that holds in that stage for longer before the flowers open. They will open, if you don’t harvest the broccoli head in time. If in doubt, harvest, even if it’s not as big as the ones in the store. It’s not going to get any bigger, but it will turn yellow and start blooming.

It’s the perfect time to harvest this broccoli even if the head is small

Broccoli (Brassica oleracea var. italica) comes in two types: the single-head Calabrese kind, and the multiple-stem sprouting kind. Both grow well in this area in either spring or fall. You’ll want to either buy transplants or start seed indoors, and look for varieties with shorter maturation dates in order to produce during our cool season windows.  The sprouting broccolis will produce lots of smaller clusters instead of one large head and usually yield faster than the single-head types. Be careful when buying sprouting broccoli seed that you are getting a quick-yield (50-60 days) variety rather than an overwintering type (more like 100 days). The latter are planted in the fall and produce in the spring, with some winter protection; if you plant them in the spring by mistake you’ll be disappointed. (Ask me how I know.)

All broccolis require plenty of water and nutrients and produce a lot better if they are spaced a good distance apart—give them 18 inches even if they’re tiny when you put them in! If you have a small garden, read on, because there are other options in the world of edible flower buds that take up less space.

One of my favorite vegetables to eat, and sometimes to grow, is Chinese broccoli or gai lan. Imagine a sprouting broccoli that’s slimmed down, with tender stems yielding narrow leaves and small clusters of flower buds that open to white flowers. The taste is mildly bitter; most of the plant is edible (leaving out the roots and any stems that have become too tough) and it requires minimal cooking time. It grows quickly, but it does tend to bolt if the weather warms suddenly, so fall harvests may be more reliable than spring.

An interesting thing about Chinese broccoli is where it fits in the brassica family tree. Most Asian brassicas are B. rapa, but this one belongs to  B. oleracea. Somehow it traveled over from Europe and was bred to fit Asian tastes.

Of course there are Asian B. rapa crops that produce edible flower buds as well. Choy sum is a fast-growing, yellow-flowered, mild-tasting plant that’s also eaten leaves, stems, and all. It needs to be harvested young and likes cool weather, not cold or hot. Yu choy is another similar crop; you can find seeds for these and many other Asian brassicas in specialty catalogs or some Asian supermarkets.

There’s a flower-bud Brassica rapa crop important in Europe, too, known as rapini, broccoli rabe, broccoletti, and other names. It’s a fairly small plant that quickly produces leaves and flower buds that have a slightly bitter flavor and are wonderful in lots of Italian dishes (there are Spanish and Portuguese relatives, too). 

Rapini (photo from Wikipedia)

The final member of this group is Brassica oleracea var. botrytis, also known as cauliflower. When you eat a cauliflower head, you are not eating flower buds. Cauliflower “curds” are in fact a botanical structure known as an inflorescence meristem, which generates replicas of itself in a pattern without producing flowers.

The inside of a cauliflower

The pattern is even easier to see in Romanesco, which is a form of green cauliflower that develops in logarithmic spirals.

Romanesco (photo from Wikipedia): MATH VEGETABLE

Cauliflower will eventually bolt, given stress factors like heat or lack of water, and in fact it’s prone to do so in our climate. It also doesn’t like exposure to cold snaps; if you put your transplants into the garden too early, the heads may not form properly. I say this about every brassica, but—look for the varieties that mature faster, and you’ll have better luck. You also have choices when it comes to color, since cauliflower comes in not just white, but also yellow, purple, and green.

Another possibility is the broccoli-cauliflower hybrid known as sprouting or green stem cauliflower. This is a plant with tender loose florets that is more reliable in warm climates. It’s popular in Asia and there are many varieties. Look for names like Karifurore, Biancoli, or Fioretti.

This one is called TJS-65 for some reason

Among all these choices I’m sure you can find a flower bud (or an inflorescence meristem) that works in your garden. July is the perfect time to start broccoli or cauliflower indoors, or to order seed of faster-growing plants to sow in the fall.

I hope you’ve enjoyed reading about many different brassicas and are inspired to grow some of them in your garden. With a few easy techniques to solve problems like pest insects, brassicas are easy to grow and very rewarding. They’re versatile in the kitchen and extremely nutritious. And it’s fascinating to grow all these close relatives that look so different and yet have much in common.

Happy brassica growing!

By Erica Smith, Montgomery County Master Gardener. Read more posts by Erica.

2 thoughts on “Beyond Broccoli Part Six: Flowers, Bud!

  1. RC July 7, 2023 / 6:14 am

    After several years trying, I finally harvested a bit of broccoli this week!
    Thanks for the tip to start them indoors this month. Is there anything else I can start indoors now?

Leave a Reply