Home & Garden Columns

Garden Variety: Selecting Plants with Natural Scents in Mind

By Ron Sullivan
Friday August 25, 2006

After a day of being olfactorily jostled by vehicle exhaust, the odd pile of dog turds by the sidewalk, and overdone, overused, over-applied synthetic perfumes, being surrounded by natural scents clears the crud from one’s mind and mood.  

Scent in flowers, like color and form, serves to attract pollinators. Big bright perfumed blooms usually don’t toss pollen promiscuously into the air and up your nose; that’s done by wind-pollinated plants with small, inconspicuous flowers. (Some of us seem to be allergic to the scents themselves, or to whatever sublimates carry them through the air, but that’s more unusual than allergies to pollen or sensitivities to petroleum derivatives.) 

Scientists looking to breed—or genetically engineer—the perfume back into modern hybrid roses have done a lot of looking into flowers’ scent production. A few years ago a group at the University of Michigan found four separate genes that code specific enzymes that prod flowers to produce scent. This happens right in the tissues of the petals and it can be amazingly precise and versatile.  

Within those petals, which may look pretty much uniform to us, plants can manufacture and release several different scents: a general come-hither near the petal’s edge and a more specific directional indicator nearer its base. This looks like an analogy to the ultraviolet markers on flowers: bees can see them; we can’t.  

If you want a fragrant garden, consider a few things before choosing plants.  

Some flowers, like those of the shrub night jessamine, mentioned last week, are overwhelmingly fragrant. Set such flowers at the far edge of your garden, to dilute the scent. Be kind to your neighbors about this, too, please. 

Like night jessamine and nicotiana, some flowers release their scents only in the evening: brugmannsia (angel’s trumpet) and some cacti and orchids, for instance. 

Daphne blooms early in the year, when we all need encouragement. Earlier still are those white narcissus bulbs you can force in a dish of pebbles and water.  

Old roses have the best scents. Shop for them when they’re blooming, to find your favorite, or take notes and keep those fort bare-root season.  

Citrus trees are famously fragrant, and many do well in big containers. If you love the scents, look for several types that bloom and bear fruit at different times. If not orange, then “mock orange,” Philadelphus—we have a fine native species. 

A nice fragrant underplanting is the humble, common, inexpensive white alyssum. The purple and pink kinds aren’t so fragrant. Alyssum re-sows generously, which is good in a city garden but makes it dangerous to plant next to a wildland; it’s already feral along the coast. Old-fashioned pinks smell wonderfully spicy; so do a number of our native annuals like Brewer’s clarkia. Sweet stock is easy to find as seedlings; heliotrope and mignonette only a little less so.  

Best is to shop a few times each season, and walk the streets and public gardens, with your nose working and a notebook and/or camera.  


Next week: fragrances don’t come only from flowers.