Steve Mellon, Post-Gazette Sage, part of an exhibit on medicinal plants at Phipps Conservatory, has anti-bacterial and anti-viral properties. Click photo for larger image.

Growing herbs is a hobby for some, a passion for others and a livelihood for a fortunate few.

Some herbs, such as anise hyssop and lady's mantle, can enhance a formal landscape planting. Nasturtiums can peek out invitingly from among fresh greens. Interweaving herbs in the garden can mean that fresh basil is available to marry with summer tomatoes.

Some plants perform double, even triple duty. Lavender can elevate ordinary beds or lemonade to the sublime. It also can soothe a headache, lull you to sleep, relieve the itch of insect bites and deter moths. By some accounts, the scent can even make lions and tigers docile!

"Medicinal Plants: Earth's Pharmacy" is an exhibit that continues through April 3 at Phipps Conservatory and Botanical Gardens. This is a rare chance to see the basic, essential elements used in everyday remedies as they grow in nature. The exhibit, which is sponsored in part by the Garden Club of Allegheny County, doesn't promise any cures, just some insight into how beneficial nature is to the body, mind and spirit.

The exhibit is divided into six categories:

Ouch showcases plants that can help with falls, wounds or other injuries.

Achoo focuses on remedies for coughs, cold and flu.

Burp explains plants that will aid in upset stomach and gastrointestinal issues.

Aaahhh features plants for relief and relaxation.

Zing highlights plants for energy, memory and good health.

Smooth features plants that can affect aging, memory and skin care.

Each herb has its own history and story to tell with uses both historical and modern. Yet, they're so common it's hard to believe that 40 percent of our prescription medications are derived at least partially or wholly from plants and that 75 percent of the world's population uses plants exclusively for their medicines. A quick tour around the garden may reveal some interesting surprises. Let's take a look inside nature's medicine cabinet.

Rosemary was traditionally believed to enhance memory and was woven into a bride's head wreath to help couples remember their wedding vows. Rosemarinic acid, a particularly powerful antioxidant among the many that are contained in rosemary, helps to counteract free radicals that may play a role in the development of Alzheimer's disease. Some of these compounds reportedly also prevent the breakdown of acetylcholine, which transmits nerve impulses. Many of these compounds can be absorbed through the skin, so try rosemary shampoo and lotions and add rosemary to your tea and see if they perk up your mind.

Steve Mellon, Post-Gazette Leaves of the ginger plant (foreground) frame a peppermint plant at a new exhibit on medicinal plants at Phipps Conservatory. Click photo for larger image.

Peppermint can be a garden thug, but it's so useful that it's hard to stay mad at it for long. Each time you take a mint (wrapped please!) as you leave a restaurant, you are relaxing the muscles in your stomach and speeding digestion. It is even useful for irritable bowel syndrome, but avoid it if you have acid reflux because it can increase the symptoms.

Menthol, the main component of peppermint, helps to balance the good bacteria in the intestine and is effective against the bacteria that cause tooth decay. Chew fresh leaves in the garden, try a cup of mint tea or, since an alcohol extraction is even more effective, opt for a mint julep!

No respectable Thanksgiving stuffing would be complete without the addition of a bit of sage. But don't stop there since sage is useful from head to toe. As a component of many herbal deodorants, it is thought to decrease bodily secretions, which is why sage tea also is used to decrease milk flow when mothers have finished nursing. Some women find that nothing relieves their hot flashes as well as a cup or two of sage tea, which is a tribute to its hormonal components.

Sage is one of the few herbs that can be harvested in the middle of winter, so just brush off the snow and use as you like. For that midwinter sore throat, try sage tea as a gargle two or three times per day. While you are at it, rub one of the leaves over your teeth. Sage has antibacterial and antiviral properties, also.

Chamomile is particularly useful for digestive problems that have a nervous component. It should be the remedy of choice for sleepless nights, particularly in the elderly. Chamomile soothes not only the digestive tract but also the skin, which is why it is a component of many skin care products.

As an anti-fungal, chamomile tea can be applied to minor fungal infections with a cotton ball. This same property makes it useful when starting seedlings. Spray starting mix with chamomile tea before starting seeds to prevent damping off disease. A member of the ragweed family, chamomile may cause allergic reactions in sensitive individuals.

A word of caution: The above information is not intended as a recommendation for self-medication or as a substitute for qualified medical advice. Check with your physician before including medicinal herbs in your health- care program. For more information, see the periodicals Herb Companion, Herb Quarterly and Herbs for Health.

This fall, as you are putting the garden to bed, take a new look at some of your old favorites. If you should happen to cut yourself, press some yarrow leaves against the wound. If it was good enough for Achilles to use in battle, we should not treat it lightly.