Peas—a must-plant for me—will go in the ground sometime in the next few days, and I didn’t sow nearly enough of them last year.
So last week I reviewed my sketches of what grew where over the past couple summers—searching for a spot to squeeze in a few more rows—and I was reminded that I didn’t plant any lemongrass last year. It wasn’t an oversight. I love the stuff. But the plant is a spacehog—and so prolific that I could never manage to use up what I harvested. Even after giving away armfuls, the volume was overwhelming.
Now, though, I’ve got the perfect use for bunches of bunches: Homemade Tonic Syrup.
Sounds fussy, I know; but it’s a simple process (it’s a simple syrup!) that’s well worth the hour-fifteen of prepping, simmering, straining, and bottling.
Refreshingly bitter—in that bracing, gotta-be-good-for-you way—I’m loving it over ice with with seltzer. And, of course, now and then with some gin.
If the spirit moves you, give it a shot.
Tonic Syrup
Adapted from Eric Asimov. Makes about 8 cups of syrup.
- 8 cups filtered water
- 6 tbsp cinchona bark (I found mine at Penn Herb)
- 1-1/4 cups lemongrass (about six stalks), in half-inch slices
- zest and juice of 1 lime, 1 orange, and 1 grapefruit
- 24 whole juniper berries
- 12 whole allspice berries
- 2-1/2 cups granulated sugar
- 5 tbsp citric acid


In a sturdy, medium-large saucepan, combine cinchona bark, lemongrass, citrus zests and juices, juniper, and allspice with all 8 cups of the water.* Bring to a boil. Reduce heat and simmer, covered, for a half hour.
Line a fine mesh strainer or colander with two layers of cheesecloth, and straddle it over a heatproof bowl. Carefully ladle or pour the hot liquid through the cheesecloth into the bowl. Discard the solids.

Rinse out the saucepan, then return the strained liquid to the pan. Add the citric acid and the sugar. Simmer over medium heat until the sugar is fully dissolved.
Funnel into small (or large) bottles, waiting to cap them until the syrup cools to room temperature. Store in the fridge for up to six months.
To use, mix to taste with seltzer or club soda (I found the sweet spot to be somewhere between 1:3 and 1:2.

*Originally, I took the extra step of dividing the water (5 cups for the first steep) and making a simple syrup (3 c water, 2-1/2 c sugar) to be added later, tasting along the way. Guess what? At full strength, it’s so danged bitter you can’t possibly do anything “to taste.” So I’ve settled on using all the water upfront and just stirring in the sugar at the end. One less pan to clean, too.
Susan, you’ve given me permission to grow lemongrass in my garden! I’ve always heard it takes over, as you mentioned, but I now have a strong case to grow some – tonic!! This with some gin and some rhubarb syrup = MUST DO. And cheers to spring garden plans!
Do it! (Just be sure to wear thick gloves when you harvest. Those leaves are sharp!)