Sense of Smell in the Garden

Author: Claire McCaughey, Master Gardeners of Ottawa-Carleton.

In this article, the first of a five-part series on the five senses in the garden, the sense of smell is explored along with descriptions of tried-and-true fragrant plants you can try in your garden.

Gardening is a multisensory experience. When you walk into a garden, you may experience such pleasures as scented white Lilium regale (regal lily), the mixed colours of Zinnia elegans ‘Queen Lime Red’, soft-to-the-touch grey Stachys byzantina (lamb’s ear) leaves, sweet-tasting Pisum sativum (green peas), and faded beige Panicum virgatum (switch grass) rustling in the autumn wind. All senses can be stimulated in the garden.

Smell and Memory

Smell is strongly associated with memory and emotions. The smell of a particular flower often carries us back to childhood or to another place.

My grandmother was an avid gardener who loved roses and had a large rose garden. I think of her and my happy childhood visits to her garden whenever I smell roses. Some associations with scent are not so obvious and so it is a challenge to identify and describe smells and even to understand why they are appealing, or not. For that reason, smell has been described as a pre-verbal sense. We often like a smell but do not always know why.

Many gardeners think of scent first when selecting plants or visiting gardens. Unfortunately, plant breeding has eliminated it from some flowers (some roses being a case in point) in favour of other characteristics such as colour (the appeal to one sense being emphasized at the expense of another).

The Scent Palette

The Scentual Garden: Exploring the World of Botanical Fragrance (Ken Druse, Abrams, New York, 2019) explores the complexity of scent profiles and identifies twelve fragrance categories (Animalic, Balsamic/Resinous, Floral/Sweet, Forest, Fruity, Heavy, Herbal/Green, Honey, Indolic, Medicinal, Rose, and Spice.)

As Druse notes, scent is not always sweet. Some plants can have an overpowering, or even downright terrible smell.

When I first started growing tropical bulbs, I planted a Sauromatum venosum (voodoo lily) in the house and placed it on the kitchen table. It flowered within days, opening just before I came downstairs one morning. I was almost overcome by the horrible smell! That plant is classified as Animalic, which to some smells like rotting meat.

Favourite Scented Plants

Below are some hardy plants in Ottawa that I have grown successfully. Or, in a few cases, I have researched and am seeking to grow them (if I can only find the plants!). I have organized them according to Druse’s fragrance categories.

Floral Sweet Scents

In the category of floral/sweet are some well-known plants, including Philadelphus coronarius (mock orange shrub), Convallaria majalis (lily of the valley), which I no longer grow due to its invasiveness, and Hosta plantaginea. Some primula and allium species are lightly scented (note that allium flowers may have a pleasant scent, but the leaves certainly do not). One old-fashioned floral or sweet annual flower I would like to try is Reseda odorata (mignonette). The only drawback with this plant is that it looks like a weed, but I am still going to try it this year.

Fruity Scents

In the fruity category is Heliotropum arborescens (cherry pie), an old-fashioned plant that I started from seed last year. It is often spoken about as having an intense and beautiful scent. A bouquet of it was laid on the coffin of American poet Emily Dickinson. After it flowered in my garden, I was initially disappointed. Then one afternoon, a fruity, rich scent wafted across the garden. Also in this category are Freesia, Oenothera biennis (evening primrose), and tulip (noted varieties that I am now looking for are ‘Apricot Beauty’ and ‘Princess Irene’).

Honey Plants

Two honey plants that are long-time favourites are Lobularia maritima (sweet alyssum) and Actaea racemosa (formerly Cimicifuga racemosa) (bugbane). I plant patches of annual Lobularia maritima every year to have the late-summer honey smell in my garden.

Scented Leaves

Many leaves are scented, especially when they are touched or brushed against. Some favourites fall into different fragrance categories, including Rosmarinus officinalis (rosemary) (Forest), Agastache foeniculum (anise hyssop) (Herbal/Green), and Gaulteria procumbens (wintergreen) (Medicinal). One that I would love to grow (but have not yet found) is Comptonia peregrina (sweet fern) (Herbal/Green)

Rose Fragrances

Roses are in a fragrance category by themselves. I have not grown either of the two most scented roses – Rosa x centifolia and Rosa x damascena. However, in recent years I have had good success with Rosa rugosa (Salt-Spray Rose) and a hybrid Rosa rugosa called ‘Blanc Double de Coubert,’ both beautifully scented. Try one or more of these scented plants in your garden this year, or experiment with other scented