Smell

Ode to the rose

Roses bring colour and fragrance to public spaces. They can psychologically boost the perception of the quality of public green spaces. Nowadays there are many varieties available that flower for a longer period of time and require only seasonal maintenance. Prickly roses can be used to create attractive and fragrant hedges that prevent ‘unwanted push-through’.

Aroma spots

Adding fragrant plants at an entrance or meeting place in a park or in a border in a park reinforces the positive overall experience.

Scented climbers, such as wisteria, honeysuckle, climbing rose and clematis, can be grown against facades, walls and noise barriers.

Scented season

We can extend the seasonal experience for seeing and smelling by including year-round interesting colourful and fragrant plants, which also attract bees, butterflies and birds. For example, by (also) using scented flower bulbs (early) in the season, such as hyacinths and certain daffodils. Also think of shrubs, such as the witch hazel, which is fragrant on mild winter days, or the snowball viburnum, which  gives off a pleasant scent in spring.

Plant scents

Perennials, shrubs and trees can be found in a fragrant assortment. Consider rhododendron, lilac, magnolia and linden.

Flowers spread fragrance to attract insects and other animals for pollination. Fragrant flowers emit their fragrance more constantly than scented foliage. The more sun and heat, the more fragrance is generally released. Still air is also beneficial.

Many flowers close after the heat of the day. The night bloomers, which begin to bloom when the sun goes down, are at their peak later. Interestingly, these mostly white flowers have a strong fragrance in the evening. They do this to attract moths and bats for pollination.

With scented plants, unpleasant odours from, for example, rubbish bins can be somewhat masked locally. There are also plants that are perceived by humans as unpleasantly fragrant, such as stinky ballote and goatweed.

Fruits and seeds may smell to attract animals that distribute the fruit. The seeds of the female trees of the Maidenhair tree (Ginkgo) can smell quite unpleasant in the autumn. This can lead to odour nuisance for residents in streets.

Memory

Scents evoke memories. People from different cultures and generations have specific associations when smelling plants from their childhood.

Scented plants are important for those who are visually impaired and for people with dementia. This principle can be applied when designing for healthcare and educational institutions. When we smell scents that we recognise, we can feel safe.

Place fragrant plants, such as thyme, lavender and rosemary, close to seating areas, walking and cycling paths. Plants with fragrant leaves, such as various geraniums, only release their fragrances touched, for example when walking by. In places where there is little walking traffic and between stepping stones, fragrant creeping chamomile or thyme can be used.

Forest bathing

Some trees and plants produce aromatics in the form of essential oils to protect themselves from harmful external influences, such as heat and insect attack.

Conifers and herbs are particular examples. The health effect of these essential substances (phytoncides) is a significant discovery. Japanese research shows that phytoncides are antifungal and antibacterial. By inhaling them, we increase the activity of our NK cells (natural killer cells). These cells play an important role in our immune system in the fight against viruses and cancer.

In addition, the scent of a forest encourages us to  breathe more deeply, which lowers our stress levels. In Japan they have a special name for this: shinrin-yoku, or forest bathing. It is a way to heal the body and mind through nature. All the more reason to plant more urban forests in and near (vulnerable) urban residential areas and to maintain them properly.