Red and golden beets from the author’s garden. Both the roots and the leaves can be cooked. (Barbara Damrosch )

One of the best musical commentaries about gardening came from the perpetually off-Broadway musical “The Fantasticks.” Two gardening neighbors sing a duet about the reliability of vegetable growing as opposed to fatherhood. “Plant a radish, get a radish, never any doubt,” they carol. “Plant a turnip, get a turnip; maybe you’ll get two.”

Now, you won’t get two turnip roots from one seed, but you will get two vegetables: an edible root and its topknot of edible greens. And if you’re short on garden space, it pays to plant a dual-purpose, two-for-the-price-of-one crop such as the turnip or the beet. Never any doubt.

Just for fun, I started a list of garden vegetables that play two roles with equal talent.

Lots of garden herbs are ­twofers. You can grow dill for its ferny foliage, perfect for summer salads, then let it bolt and harvest the seeds when they turn brown, for use in baked breads and other all-season dishes. Cilantro, pungent when green, yields the seed we call coriander, useful in curries and in cookies with a hint of spice.

Caraway plants are pleasantly aromatic, including the seeds, which give a whole new elegance to boiled cabbage. As biennials, they will produce only seeds the second year.

Sometimes dual use means selecting different varieties. The classic stalk celery is botanically the same as the root celery, which is more popular in Europe. But you cannot get both from one strain, because one is bred for tasty, juicy stems, the other for big, celery-flavored globes. Nor can you get flat edible pod peas and those grown for their tender seeds from one sowing. You must choose.

With fennel, as with celery, there’s a bulb form and a stalk form, but I’ve found bulb fennel to be a good dual-use crop. When I harvest the delicately licorice-flavored bulbs (actually enlarged stem bases) for roasting, braising or grilling, I save the lush fronds of foliage. Chopped and scattered over a salad or baked into a gratin, they’re just as useful as other leafy herbs such as basil and dill.

Some vegetables give an extra performance that is less well known than the main act. Bok choy varieties with firm, wide lower stems or ribs offer the option of using the tender part of the leaf raw and the firm part in a stir-fry or soup. This can also be done with Swiss chard and kale. The towering stem of bolted lettuce can also be cooked that way, even after the foliage has gone by.

Brassicas such as broccoli produce seedpods that are flavorful and can be stir-fried. There’s even a radish variety called rat tail designed for this purpose.

With certain old corn varieties, such as the deep-red Bloody Butcher, you can pick an early crop for fresh eating and leave some ears on the stalk to grind for cornmeal or make into fall ornaments.

I can think of more three-act wonders. A few garlic shoots can be snipped early in the season as delicious green garlic, leaving the rest to make bulbs. If you grow the rocambole type that form loopy flower stalks called garlic scapes, you can cut those and roast them in olive oil and butter for an amazing treat.

Ordinary garden beans — especially the flat Italian varieties such as Garden of Eden — are great at three stages: snap beans while the pods are tender, shell beans when the seeds have formed but not hardened, and dried beans after the seeds are mature.

Vining and bush-type squash yield not only fruits but also large golden blossoms that are the pinnacle of edible-flower cuisine. For fritters, stuff them with your favorite cheese (and maybe an anchovy for protein and pizazz), then roll in batter and fry in olive oil. For Act 3, cut off the tips of the vines to direct the plant’s energy into ripening the last fruits, and make fritters out of the tips just as you would the flowers.

Economical crops such as these will give you bounty and a varied diet. But still, it’s no crime to grow and enjoy a space-
hogging but exquisite single-use food such as the muskmelon. It’s not even particularly versatile in the kitchen. But if you pick a ripe one, cut it open and eat it outdoors in all its sweet, fragrant perfection, you will have no regrets.

Tip of the Week

Check cucumber and squash plants regularly for half-hidden fruits before they get big. Diligent harvesting will keep plants productive and allow the gardener to check the arrival of cucumber beetles and squash bugs before populations build. Examine the underside of leaves and handpick eggs, larvae and adults.

— Adrian Higgins