Gardening with Laurie: Woody perennial herbs

By Laurie Brown
Reader Columnist

Herbs can be some of the easiest plants to grow for the home food garden. They add interest to meals or tea, and some are quite pretty.

Lavender. Courtesy photo.

Some of the hardy herbs are sub-shrubs — plants with a woody structure, but on a smaller scale than most shrubs. Sage, thyme and lavender fall into this category. These plants are from the Mediterranean area, and like well-drained, even dry and rocky, soils. They will die if they sit in water — a problem in our wet springs. A slight slope is a good place for them — preferably south-facing. As an example of the difference this can make, I have trouble getting sage to live for more than about 4 years, and sometimes lose a lavender in a wet winter. In a garden I tend, there are huge lavenders and the biggest sage I’ve ever seen, on a steep slope, which are at least 10 years old.

The only really reliable sage is the regular salvia officinalis; the tricolor and purple ones are slightly less hardy. Pineapple sage is strictly an annual here. Among lavenders, the lavandula angustifolia, English lavender, is the hardiest. Within that species, though, you can find dark or light purple, pink or white flowers. Thyme comes in many varieties; Thymus vulgaris being the culinary type — the types sold as creepers for paths are pretty but scentless. Thyme also comes in lemon scented varieties, as well as both golden leafed and variegated.

Sage and lavender form true woody structures, which need pruning for shape once a year, as well as removing some old wood after the plant is about three years old. Thyme makes a woody stem, with lots of wiry stems covered in tiny leaves. It can be sheared almost to the ground in winter once it gets to be around three years old; it develops too many old stems that don’t produce many leaves as it ages. Thyme spreads rapidly, and you’ll need to keep it in check. It is, thankfully, easier to control than mints are, having no underground runners. Just dig it out and throw it on the compost or in the chicken yard; it’ll make them smell sweeter.

Like all herbs, you don’t want to fertilize these plants much. I give young ones some fertilizer to give them a good start, so they are large enough to survive being planted out. From there on out they only get fertilized lightly in spring — I like to use about fourth the amount the bag says to use. Too much fertilizer produces lush green growth which contains a lot of water rather than essential oils. The same applies to watering too much; once the plant is settled in and resumed growing, only water when the soil dries out to one-inch deep. I don’t mulch herbs; it holds too much moisture and can promote rot in winter. Keep summer mulch an inch away from the stems. If you have clay soil, you will be better off planting your herbs in containers, even though that increases the risk of loss in winter.

To harvest, simply snip the leaves off sage, or cut new growing tips. It is useful in sausages, pork and turkey. With lavender, cut flowers right before they open. They are good in tea, and lavender is divine added to lemon-baked goods. Thyme can have the whole wiry stem cut and added to most any savory dish (essential to jerk) it can be removed from before serving; if you want it dispersed into the food, run your fingers up the stem rapidly, and the leaves should zip off in your fingers. Any of these can be thrown on the coals or into a smoker to add flavor to grilled foods.