By T. Eric Nightingale, UC Master Gardener of Napa County

One of my favorite parts of home gardening is growing my own herbs. Fresh herbs add depth of flavor to food that dried herbs simply can't match, plus many documented health benefits. A single herb has more culinary applications than a single vegetable and needs little space to produce all you need. I tend to think of herbs as annuals, but there are many perennial herbs as well.

Spring is an excellent time to plant herbs. Nurseries sell the most popular herbs as seedlings, but many are easy to grow from seed. When choosing a plant, be sure to know how much space it will need when mature. Some herbs, such as rosemary and mint, grow large in a relatively short time, often engulfing nearby plants. Put these herbs in their own pot where they can conquer their domain unchallenged. Alternatively, you can plant two vigorous growers in a single container and watch the battle royal play out over the summer.

We're all familiar with parsley, sage, rosemary and dill. But there are many less-common herbs you can grow to add some new flavor to your life.

One favorite of mine is Stevia rebaudiana. You are likely familiar with the sugar substitute Stevia, a refined version of this plant. The leaves alone are quite sweet and can be added to drinks and desserts to contribute sugar-free sweetness, an especially nice treat for any diabetics in your family. S. Rebaudiana is native to South America and adapted to environments more humid than Napa Valley. I've grown it successfully by keeping it well-watered and providing shade in the late afternoon.

Stevia is a perennial and will overwinter in Napa Valley. It does not like soggy soil so make sure the soil drains well and dries out between watering. The leaves can be eaten fresh or dried for future use.

For a decorative and edible addition to your garden, try the annual Perilla frutescens. Commonly known as shiso, it can be found in red and green varieties. The leaves are wide and attractive, somewhat resembling Coleus.

You may find shiso growing on roadsides and in vacant lots. It has become a weed in North America. It has been used in kitchens across Asia for centuries.

P. frutescens grows well in full sun and likes moist, well-draining soil. It has a mild flavor and can be used raw as a garnish. Shiso has recently experienced a boost in popularity in the United States, and one can find dozens of recipes using it.

 Another interesting herb is the perennial Myrrhis odorata, also called myrrh or sweet cicely. This is not the myrrh of biblical history. Sweet cicely can reach six feet tall and has attractive leaves resembling those of a fern. The leaves have a licorice-like taste similar to anise.

In the past cicely was thought to relieve digestive problems; it was used medicinally for centuries. The plant works double-duty as the roots are also edible. Sweet cicely is accustomed to a cooler climate than Napa Valley, but it can be grown here if given afternoon shade and kept well-watered.

For a bit more zing, try Dysphania ambrosioides, an annual known in the Mexican kitchen as epazote. It is native to Central America. Epazote is a leafy green with a flavor often described as pungent. It can be an acquired taste, but you may find the effort worthwhile as epazote is said to reduce flatulence caused by eating beans and some vegetables. Napa Valley has a prime climate for this herb. It prefers heat and lots of sun, and it isn't picky about soil quality.

If your culinary options have been getting stale, I encourage you to explore the many alternative herbs out there. You are certain to find new flavors to reinvigorate your meals.

The UC Master Gardeners are volunteers who provide UC research-based information on home gardening and answer your questions. To find out more about upcoming programs or to ask a garden question, visit the Master Gardener website (http://napamg.ucanr.edu) or call (707) 253-4221 between 9 a.m. and noon on Mondays, Wednesdays or Fridays.