Scented Geraniums--herb of the Year 2006

Madeline Wajda
Adams County Master Gardener

Scented geraniums are not your grandmotherís red-blooming garden geraniums, although they all belong to the same plant family, Geraniaceae. The scented geraniums are actually of the genus Pelargonium, from the Greek "pelargos," or stork, because the ripe seed pod resembles the head and beak of a stork.

Most of the 250-280 varieties of Pelargoniums came originally from the Southern Hemisphere, mainly South Africa where they are half-hardy perennials and grow shrub-like. The original plants were introduced into Europe by sailors in the early 1600s. Naturalists on board these ships collected plants as possible food or medicine and brought them back to botanic gardens in Europe where complex hybrids of the original species were created.

It was not until the mid-nineteenth century that the French discovered that the essential oil extracted from rose geraniums could be used as a substitute for the rare and very expensive oil of roses for perfume making. Soon, large amounts of rose geraniums were grown in southern France and North Africa for oil production. Their popularity reached its height in the Victorian Era, when no bouquet or basket of flowers was complete unless it contained several varieties of scented geraniums. At this time, infusion of rose geraniums was dabbed on the arms and neck by proper Victorian ladies "before leaving the house."

There are five basic families of scented geraniums determined by fragrance: rose, citrus, mint, fruit/nut/spice, and pungent. The first three are the most commonly used for their fragrance, especially in cooking. The variety name is not always indicative of the plantís real scent; it is best to rely on your own nose before adding leaves or flowers to food or potpourri. Be certain to use only organically grown pelargoniums in food.

Pelargoniums are tender perennials, hardy only in zones 9-10. They can be grown in the ground or in pots; in either case, they must come indoors when outdoor temperatures go below 45 degrees. Outdoors they thrive in full sun, except for the peppermint varieties, which will grow in the sun but are happier in shade or semi-shade. The flowers of all pelargoniums tend to be small, but the textures and colors of the leaves are a beautiful addition to any garden. They can be planted in borders, as ground covers, in rock gardens, or in mass plantings. Planted in the ground, the some plants will grow so large that they can be difficult to bring in before the frost. In this case, take cuttings in late summer to grow smaller plants for bringing indoors for winter. To take a cutting from a healthy stem, cut just below a node and strip off most of the leaves. The use of rooting hormones is not necessary, but if they contain a fungicide, they may be helpful when used at their mildest strength. Cuttings will root in a variety of well-drained media, but not in water (unlike your grandmotherís red geraniums). Sterile sand, perlite, or a commercial starting mix is satisfactory. Donít place the new cuttings in direct sun or use bottom heat for the first 24 hours, after which bottom heat of 68-76 degrees helps speed root formation. Keep moist but not wet. The smaller-leaved, short-stemmed varieties such as ĎApple,í ĎCoconut,í etc. are best propagated by seed in a sterile medium.

Indoors in pots with a soiless mix and good drainage, give pelargoniums all the sunlight you can, regular watering, and relative coolness. Daytime temperatures of 65-70 degrees with an evening drop of about 10 degrees are ideal. They will also need good air circulation. Water early in the morning when the top of the soil feels dry. During the growing season, fertilize at half-strength every other watering; the rest of the year, fertilize at the same dosage once every eight waterings. A teaspoon of Epsom salts added to the fertilizer solution every fourth watering will give your plants the extra magnesium they need. When ready to transplant out, be sure to harden off first and cut the bottom half inch of roots and soil off to encourage new root growth. Pelargoniums prefer a slightly acid soil, pH of 6.0 to 6.5, and soil that is well drained. Use a balanced fertilizer, such as 15-15-15; switching to 10-15-10 when plants show signs of budding. Pinch growing tips until desired shape is achieved.

Outdoor pelargoniums do not usually have many pests. Indoors, they are subject to mealybugs, whitefly, aphids, and, sometimes spider mites. Strong sprays of water will dislodge the insects; follow up with insecticidal soap every few days until pests are gone. To prevent diseases, provide your plants good ventilation, careful watering (avoid watering the leaves as much as possible), sterile pots and potting soil, and prompt removal of dead leaves.

If you are new to cooking with scented geraniums, a good way to begin is to make a white cake mix placing 5 rose geranium leaves, dark top sides down, in some greased and floured pans. When layers are baked and cooled, carefully remove leaves; frost the cake, garnishing with rose geranium leaves and flowers. Chocolate cake mix works well with peppermint geranium leaves. From there, you can begin adding finely chopped geranium leaves (center vein removed) to cookie or other baking mixes. Steep a few leaves in tea. Make rose geranium jelly by steeping rose geranium leaves in apple juice for about 20 minutes, straining them, and then following a recipe for making apple jelly. Look for other recipes at herb growers everywhere and experiment with this fascinating Herb of the Year for 2006.

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