Bright yellow kale blossoms add color to a dish of sauteed kale tops in the author’s kitchen. The edible blooms are tender and sweet. (Barbara Damrosch)

When I first grew broccoli raab in the 1990s, I figured I was doing something wrong. I liked the way it produced small shoots rather than big heads and that edible leaves, stems and buds were all part of the deal. But they were bitter, a fact I chalked up to summer weather. Many cabbage relatives — brassicas — taste best when it’s cool.

I’ve since learned more about this popular Italian crop, also known as rapini or cima di rapa. When Bill McKay, the founder of the catalogue Seeds From Italy, wrote about raab, he advised gardeners to direct sow the crop and thin it twice as it grows. “You do not have to grow it in cool weather,” he asserts.

The classic way to cook raab, he says, is to boil it until soft (“none of this crunchy texture”), drain, and reheat in olive oil, garlic, red pepper flakes and maybe a little cheese.

And yes, it’s slightly bitter. Italians like it that way.

Years later, searching for a sweeter version, I discovered broccolini, a trademarked green sold in produce markets that is a cross between broccoli and a leafier Asian vegetable called gai-lan or kai-lan. So I grew a variety called Happy Rich, another gai-lan/broccoli cross but one for which I could purchase seeds (from The plants were stately candelabras, somewhat blue-green and covered with small, tasty shoots. These bore white flowers, which, unlike those of American broccoli, didn’t turn brownish when cooked.

The brassicas are a wide genus, and it might seem odd that cultivated crops as different as cauliflower, cabbage, broccoli, kale, kohlrabi and Brussels sprouts were all derived from a wild plant on the coasts of northwestern Europe. Nevertheless, they all share a great love of rich soil. They flourished in the fertile soils of gardens and lent themselves to creative improvements.

They are sought by cabbage worms, flea beetles and hungry humans in search of nutritious greens. Their flowers, if allowed to form, are always four petals in a single cross shape, hence the name of the larger family to which they belong, the crucifers.

Aside from feeding them heavily, one of a gardener’s strategies in growing brassicas is to keep them from blooming. When your broccoli bolts, with clusters of yellow flowers waving, the bees are happy, but no more heads will form. So you pick regularly or have new transplants coming along to replace bolted ones.

Kale, though cold-hardy, is a crop we once thought a waste of space in our unheated winter greenhouse, because it didn’t put out fresh leaves if cut. If left to overwinter, it bolted straightaway when spring came.

But not long ago, we discovered that certain kale varieties, most notably Western Front (from ), would produce new growth when cut all winter and into early spring.

This year, when the plants eventually bloomed, sending up narrow, bright yellow clusters like upside-down brooms, a funny thing happened. Gus, a member of our farm crew, started eating the tops raw — flowers, leaves and stems — all of them tender and sweet.

There they were, the perfect brassica shoots hiding right under my nose as kale. Best of all, the golden color of the flowers was undiminished by cooking. I cut the tops about six inches long and simmered them in a covered pan with a little water, lots of olive oil and grated garlic. In five minutes, they were done — with just a bit of crunch.

Damrosch is the author of “The Four Season Farm Gardener’s Cookbook.”

Tip of the week

House plants such as citrus, clivias and philodendrons that summer outdoors can be moved outside — most are adapted to low light conditions and should be kept in partial shade. Keep them in a sheltered spot and full shade for a couple of weeks before moving them to their final location. Remove saucers under pots to allow proper drainage.

— Adrian Higgins