Trim the stem ends so the beans fit into pint-size canning jars. Pack the beans into four 1-pint jars, tips down. Tuck in the garlic and the dill and tarragon sprigs. Add 1 teaspoon each of the peppercorns and horseradish to each jar.
In a large jar, combine the vinegar with the salt and sugar. Close the jar and shake until the salt and sugar dissolve. Add the water and shake again. Pour the brine over the beans; if the beans are not completely submerged, top off the jars with water. Close the jars and refrigerate the beans for at least 24 hours before serving.