By Robin Parer
Wander out into the gardens at Marin Art and Garden Center and look for the scented leaf pelargoniums growing there. At garden shows many people, on first encountering and smelling the leaves of these enigmatic plants, express surprise. A common question is “what did you spray on them?” When told “nothing”, some look curious, others seem faintly startled before sadly shaking their heads and drifting away. Of course there are avid collectors as well.
My nursery has been hunting scented leaf pelargoniums for many years (and yes, gardeners do call them scented leaf “geraniums”; more on that below). We have about a 150 diﬀerent ones and are still in collecting mode. I often wonder how to best explain these well loved, homey and fascinating plants that seem to mimic the scents that many of us say we recognize: plants whose scent of their leaves is familiar enough to give them common names such as ‘Apple’, ‘Rose’, ‘Cinnamon’, ‘Lemon’, ‘Lime’, ‘Peppermint’ ‘Nutmeg’ and many others. Their flowers are not the point. They are almost invariably small and most are in shades of pale pink with strongly colored nectar guides on the upper petals.
Scented leaf pelargoniums are almost classic “pass-along” plants. Gardeners have been giving cuttings away to friends and neighbors for over 175 years. Our grandmothers, great-grandmothers and generations before that knew all about them. The scented leaf pelargoniums can be found on windowsills of houses and apartments; are treasured elements in scented gardens and gardens for the sight impaired; they grace herb and vegetable gardens, and can be found along walkways and around outdoor seating in gardens, close to where their fragrant leaves can be pressed between trailing fingers. Whereas other pelargoniums have waxed and waned in popularity among the gardening public, scented leaf pelargoniums have never really gone out of fashion.
Some gardeners and nursery people call them scented “geraniums” but this is incorrect. The scented leaf group belong to the genus Pelargonium in the family Geraniaceae. Geraniums, are in the main, herbaceous perennials. These pelargoniums are from a group of small woody sub-shrubs that come from Southern Africa, many from a Mediterranean climate rather similar to parts of California. They are accustomed to a mild and rainy winter and a hot and dry summer. But all can adapt to light summer watering if they are planted in well drained soil. They can endure high summer temperatures of well over one hundred degrees Fahrenheit and low winter temperatures in the thirties to upper twenties, if they are acclimatized. Scented leaf pelargoniums are survivors in abandoned gardens, lush monsters when too well fed, and attractive and well behaved if they are periodically pruned and fed a low nitrogen diet during the growing season.
Geranium oil, which is derived from a few scented leaf pelargonium species, has been an important commercial product in the past, but less so today, when the oils can be easily synthesized in a laboratory. The natural product, however, has a depth and intensity which is infinitely more interesting. The components that give the scented pelargonium leaves their particular scents are located in glandular hairs on both surfaces of the leaves. The scent can be released by gentle pressure on the leaf. Around one hundred and twenty volatile constituents have been identified. These will vary in number and quantity depending on the scented leaf selection. There is no general agreement about the appropriate common name for the scent for each of the scented leaf selections. A blind test with half a dozen plants and a small group of people will produce wildly diﬀerent names for the scent for each plant. Although there is usually general agreement when the plant’s name is revealed after the test.
Deer, whose dietary habits are well known to gardeners, seldom sample the leaves and flowers of scented leaf pelargoniums. Insects are usually absent when the plants are grown outside, although aphids and whitefly sometimes appear in enclosed areas. Pelargonium budworm and rust, the scourge of zonal pelargoniums, are not found on scented leaf pelargoniums. Botrytis and verticillium wilt, which can occur under poor sanitary conditions in greenhouses, are usually not a problem either.
Many retail nurseries often oﬀer small selections of scented leaf pelargoniums, but gardeners very often don’t realize how many diﬀerent selections of scented leaf pelargoniums are available. Herb nurseries are sometimes a good source for a wider selection. As well as tried and true varieties that most people are familiar with, there are a few hybridizers who occasionally produce one or two new ones. A problem that sometimes arises concerns the naming of these plants.
Confusingly, nurseries in diﬀerent parts of the country will give diﬀerent names to the same plant. Let your nose be your guide.
Occasionally nurseries do not carefully select which scented leaf have the sweetest and most attractive scents. Not all do. There are forms and hybrids of Pelargonium quercifolium that are nose-turningly pungent, although it must be said that some people like them. It is generally agreed, but not by every single person, that P. trifidum smells like dead fish.
A number of scented leaf selections are found among pelargonium species in the wild in South Africa. These are species pelargoniums not hybrids made in cultivation. If you look at a group of the same pelargonium species, you will find that there is often considerable variation in size, leaf and flower color in wild populations and even variation in scent. P. odoratissimum, the apple scented pelargonium, has, for example, a very variable scent, depending on the selection. The leaves of some plants smell almost bitter and some have little scent at all, and then there are usually a few whose scent is apple-like and sweet. It is a good idea to smell a range of plants in each scent you have selected to see which one you like best. Propagation should always be by stem cuttings as seeds will show variability in plant habit as well as scent.
Scented leaf pelargoniums grow very rapidly and can easily outgrow small containers in a matter of weeks. Being woody semi-shrubs, they can rapidly look unattractive unless they are groomed and fertilized. Once a month, pinching out with thumb and forefinger the two top leaves and the growing point on individual stems can force more bushy growth and can control height. Use the electric hedge trimmers only as a last resort. Fertilizing with a low nitrogen fertilizer such as 5-10-15 will produce a more compact plant.
Herb societies, “geranium” societies (usually focused on pelargoniums), although they themselves are becoming an endangered species, often have plants available, and individual authors have published numerous booklets and recipes on utilizing the leaves of scented leaf pelargoniums for cooking, potpourri and for medicinal purposes. The web is a good source of information on these plants.
As a nursery we don’t recommend that anyone ingest scented leaf pelargoniums. We don’t know who might be allergic and we want to keep all our customers safe. But do enjoy them for their old fashioned charm and scent.
The following list, not of the top twenty, because we change our minds frequently about which we like best, are some of the most popular scented leaf we sell and we have found that customers invariably respond positively to them:
P. ‘Ardwyck Cinnamon (cinnamon) small soft grey lightly toothed leaves on a small upright mounding plant; small white flowers; containers. Pinch growing tips to shape.
P. ‘Attar of Roses’ (sweet rose) the sweetest rose scent; mid green, softly hairy dissected and lobed leaves, small pale lavender pink flowers in umbels; strong growth; herb garden; pinch to shape.
P. ‘Chocolate Mint’ (mint) densely felted, very large hairy mid green leaves with a prominent brown blotch, most noticeable on young leaves; small pink flowers; can be used as a ground cover or, when growth is pinched back, as a container plant.
P. citronellum (very strong citrus) harshly hairy palmate leaves; strong pink flowers with dark veins and red blotches on the upper petals; a tall upright plant; good as a clipped single stem standard in the ground or in a container.
P. crispum ‘Cy’s Sunburst’ (lemon) tiny crinkled yellow and green leaves and pale lavender flowers on tall narrow stems; upright growth; herb garden in mild areas or a container plant; is frost sensitive below freezing.
P. denticulatum ‘Filicifolium’ (woodsy) very finely dissected mid green leaves; small lavender flowers; used as a filler in bouquets in Victorian times; herb garden in mild areas, or as a container plant when growing tips are pinched back.
P. ‘Fragrant Frosty’ (rose) a P. graveolens type with mid green, medium dissected leaves, the tips of which are dipped in white; small pink flowers in clusters; a handsome pot plant or use in the front of an herb garden.
P. ‘Ginger’ (ginger) soft leathery dark green leaves on vigorous upright plants; lavender pink flowers with cherry veins; pinch to shape; locate in the back of the herb garden.
P. grossularioides (coconut – yes, it really smells of coconut) slightly indented small shiny green leaves; minute magenta flowers; treat as an annual; self seeds in the herb garden; remove unwanted plants.
P. ‘Lady Plymouth (rose) compact and handsome medium dissected green leaves with cream variegation on the margins; small pink flowers in clusters; ideally suited to containers due to its relatively small and compact size.
P. ‘Lemon Meringue’ (lemon pie) small slightly rough lobed leaves; light pink flowers; upright container plant, control shape with pinching the growing tips of the branches.
P. ‘Lilian Pottinger’ (soft sweet camphor) a P. odoratissimum ‘Apple’ x P. x fragrans ‘Nutmeg’ cross. Light gray green, shallowly dissected leaves; sprays of small white flowers; compact and attractive in containers, or can be used as an edging in herb gardens or draping over walls.
P. ‘Lime’ (lime) dark green leathery toothed leaves; mid lavender pink flowers with purple veins; a tall rangy plant for the herb garden; must be pinched for shape.
P. ‘Marie Thomas’ (men’s eau de cologne) scalloped roundish leathery leaves, light lavender flowers; large billowy plant, good for hanging baskets; pinch to shape.
P. ‘Mint Rose (mint rose) tall, fairly compact; large grey-green hairy dissected leaves; strong scent; pale lavender flowers in umbels; herb garden or containers; pinch to shape.
P. odoratissimum ‘Apple’ (sweet apple) large scalloped soft mid green leaves; tiny white flowers in sprays; an attractive rounded shape in containers.
P. ‘Peach’ (peach or gooseberry) tiny crinkled dark green leaves randomly splashed with cream; small pale pink flowers with cherry veins on upper petals. Remove totally green growth when it occurs; ‘Peach’ should always be variegated; containers or the herb garden; pinch to shape.
P. ‘Prince of Orange’ (orange) slightly leathery small toothed green leaves; pale pink flowers with attractive blotches and veins; upright shrubby growth; for the herb garden.
P. ‘Strawberry’ (strawberry candy) small slightly glossy and toothed mid green leaves; very light lilac flowers with raspberry and plum veins and streaks; untidy flopping habit; keep neat by pinching; needs excellent drainage; containers.
P. tomentosum (peppermint) large densely hairy, shallowly lobed mid green leaves; small sprays of white flowers; large billowing ground cover or pinch to shape for a container. You can find this variety growing under the sign for The Studio on the Center grounds.
By growing scented leaf pelargoniums, we are connecting ourselves to a gardening tradition that goes back to the mid 19th century. It is a simple way to experience the same pleasures as our ancestors, and, at the same time, to enjoy novel sweet scents from a rather surprising source.