David Robson: How to help your herbs
Think petunia, bluegrass, tulips and squash.True annual plants by definition are herbs, because they die within one year and never develop woody tissue. Biennials would probably be in the same group because they die within two years. Perennials can be either herbs or woody materials.
Horticulturists define herb differently.
Herbs serve many purposes, from culinary flavors to aromatic fragrance to medicinal values. We use some, such as certain chrysanthemums, to control insects. A few herbs, such as indigos and beets, are used to dye fabric.
Gardeners concentrate on cooking and fragrance.
With herbs, it’s natural to bring up the term spice. “Herb” and “spice” are used interchangeably, much like fragrance and aroma, but there are differences.
When we think of herbs, we generally think of leaves and stems such as oregano, rosemary, basil and sage. Plants are soft and succulent. Many die back to the ground every year; some come back. We think of mints, which flavor everything from mouthwashes to juleps, with the former sometimes masking an excess of the latter.
