Garden writers don't generally have a good excuse to hang out in bars and distilleries. But it was all in a day's work for Amy Stewart as she researched her sixth book, "The Drunken Botanist: The Plants That Create the World's Great Drinks" (Algonquin Books of Chapel Hill, $19.95).

That's not to say it was all martinis and mojitos, all the time. Stewart also did extensive horticultural research, soaking up history and lore about the plants, flowers, trees, fruits and even fungi that go into the world's libations. Virtually every growing thing, from bamboo to birch sap, has been turned into booze at some point in human history, according to the book, which includes 50 drink recipes.

Stewart will be in Minneapolis on Thursday to talk about her book, sign copies and share sips of wine produced from cold-hardy grapes, courtesy of the University of Minnesota, which has developed several varieties. We caught up with the author and blogger (www.gardenrant.com) at home in Eureka, Calif., where she owns an antiquarian bookstore.

Q: What plants would you recommend to a lazy gardener who wants to grow a great drink?

A: First is mint. If you can't grow mint, you truly are a terrible gardener. For drinks, you should grow spearmint, not peppermint. If you want to make juleps, grow Kentucky Colonel, a Southern strain. If you're more of a mojito drinker, grow Mojito mint, a strain from Cuba, the very same mint they're using in Havana.

Depending on where you are, grow whatever fruit you like, a berry or a fruit tree. Ever-bearing strawberries, which have a longer season, are good for strawberries muddled into strawberry daiquiris, rum or vodka drinks. I encourage people to experiment.

Q: How about if you want to make drinks that will impress your friends?

A: Unusual things. I like to grow Redventure celery. It's an heirloom cross, with dark-red stalks the size of a pencil, thin like a swizzle stick. I was pleasantly surprised by how much I used celery in savory drinks once I had it.

It's nice to have something that looks different and will surprise people. Currants are good, too. You can make your own cassis. It's a fun thing to grow.

Q: Name a cocktail that goes from so-so to fabulous with fresh ingredients.

A: A margarita. When you order an ordinary margarita at a run-of-the-mill restaurant, the tequila is probably mixto, which means only part agave, mixed with cheaper tequila or grain alcohol. The artificial flavoring and sweeteners in most margaritas are kind of nasty. I'm not really a margarita drinker — I've had so many bad ones. But you can make a great margarita. Get an excellent tequila, 100 percent agave. It's worth it. Use freshly squeezed juice from a whole lime. Citrus juice gets bitter and nasty quickly. And get a high-quality orange liqueur that's drinkable on its own, like Grand Marnier, a little dash of real sweetener, like actual sugar or agave syrup. Everything fresh and well-made.

Q: How did you come to write this book?

A: The "aha!" moment was sitting around a hotel lobby in Portland, Ore., with a friend who's an agave expert. Someone had just given him a bottle of gin. He said, "I'm not much of a gin drinker." So I started gathering up ingredients for a drink I knew he'd like, with fresh jalapeños, some cilantro, cherry tomatoes — nothing but plants. We got to the liquor store and I realized that's true of all these bottles. They all started with plants. I said, "Somebody really should write a book about that," and he said, "YOU should write a book about that."

Q: What was the most interesting thing you discovered?

A: There are a lot of plants that have been turned into alcohol that you never think about. Like sorghum, a grain. In Africa, they use it to brew homemade beer. In China, they use it to make a white-lightning-like spirit. A guy in Indiana is making a nice rum-like spirit using sorghum molasses from Amish farms down the road. And sorghum is gluten-free.

Q: What's your favorite spirit or cocktail?

A: I like a Manhattan. It's a lovely drink. I have been drinking Lillet, a French wine blended with citrus, herbs and spices, a little more boozy than regular wine. It's nice mixed with other things. I'll have that with dinner.

Q: What were you drinking the last time you were a drunken botanist?

A: I don't know. I'm on the road right now. I tend to be very sober when I travel. It was probably something great, like an Old Fashioned.

Q: What's the best plant-based drink for a hangover?

A: Hmmm. Probably coffee. Or water with a little lemon juice. It's better not to drink too much, but if you do, you just have to give your liver a rest, let it do its work. There's nothing for a hangover but time.

Q: Aside from the drink recipes, what do you want readers to take away from your book?

A: To understand that everything that gets made into alcohol starts with a plant. They're all botanical. That's the point. Except for cheap synthetic stuff that no one should be drinking.

Q: Did you find any exceptions to that rule?

A: In Mongolia, they drink fermented mare's milk. You make do with what you've got.

Kim Palmer • 612-673-4784