Pelargonium

These are tender, shrubby, and herbaceous flowering plants. The shrubby kinds are found wild in southern Africa and the herbaceous kinds in Asia Minor and Syria. Pelargoniums are divided into many groups, one of which the Zonal Pelargonium, commonly known as Geranium, is the most popular. Geraniums have a woody base but the young shoots are soft and tender. Under favorable conditions these plants can grow up to 3 feet or more. There are some varieties called Dwarf Geraniums that usually don't exceed 8-9 inches in height and some that are even smaller called Miniature Geraniums. Their roundish leaves have long stems and can be 1-4 inches in diameter. They have wavy edges and unequal lobes at the base. The entire plant is coated with soft, fine fuzz. There are many varieties that have variegated foliage. Those with creamy white and green are called bicolors. In tricolor and quadricolor varieties, the beautiful leaves are marked with two to three different colors, such as deep purple, pink, milky white, orange, yellow, bronze, red, or coppery-red. Their flowers are normally five-petaled and in dense clusters at the ends of strong, erect stalks. There are single, semi-double and double flowered kinds that come in a large range of colors such as crimson, scarlet, red, rose pink, salmon-pink, white, and purple. A few varieties have petals that are clearly dotted with pinpoints of red or pink. These are called Birds-egg Geraniums. Geraniums can be planted in windows or porches and in greenhouses. If they are carefully managed, they will bloom all year round. Ivy-leaved Geraniums are very distinct in their growth from the Zonal Pelargoniums. This group of Geraniums has thin, trailing stems and leaves that are shaped like those of the Ivy. Their single or double flowers may be crimson, scarlet, salmon-pink, pale pink and white. Because of their trailing habit of growth, they're useful for growing in hanging baskets, as pot plants trained to stakes, or for summer bedding. Showy Geraniums are hybrids classed as Pelargonium domesticum. They have woody stems, but the shoots aren't as stout as the Zonal Pelargoniums. The leaves are toothed at the edges and wrinkly. The flowers are large and richly colored with some varieties having noticeable blotches. The plants in this group are grown only for summer decoration in the greenhouse or sunny window. In the class of scented-leaved Geraniums, the foliage is varied and very attractive and when crushed, give off a strong, aromatic scent resembling rose, cinnamon, mint, lemon, coconut and others. Fresh leaves may be used in baking, to add flavor to fruit cups, or in beverages or finger bowls to add an interesting aroma. Dried leaves are used in teas, tisanes, potpourris and sachets. The are great window plants and nice for the garden in the summer. A herbaceous pelargonium, P. endlicherianum, is a perennial that can grow about 2 feet tall and have rather fleshy stems covered with fuzzy, heart-shaped leaves. They produce clusters of rose-colored flowers in the summer. In mild, frost-free climates, such as California, Geraniums may be grown outside all year round. They thrive in a variety of soils and in full sun or partial shade. They should be trimmed in the autumn and every once in a while throughout their growing season. During the growing season they should be watered occasionally to ensure free growth and the retention of their leaves. The greatest enemy is frost. The Martha Washington types are in danger at 28-degree temperatures or lower; the Zonal and Ivy-leaved varieties are at danger when the temperature dips below 25 degrees. Plants that have their tops injured by frost may recover if they're trimmed back to good wood. Covering the bases with a 6-inch mound of coarse sand in the fall will often prevent the frost from totally killing the plant even though the tops may get injured.

Pot Cultivation

The best compost to use for Zonal pelargoniums consists of two parts of fibrous loam, one part of leaf mold or peat moss, a little lime, and a generous addition of sand. After potting, no water should be given until the soil is almost dry, then it should be thoroughly saturated. Continue with this method of watering until they have grown a sufficient amount of roots, and throughout the summer, weekly applications of fertilizer or liquid manure should be given. Too much shade and nitrogen in the soil will encourage lush growth and few flowers. Towards the end of summer, the water supply should gradually be reduced. During the winter, except in areas with mild climates, they must be kept in a room or greenhouse with temperatures between 40 and 50 degrees. From October to March, just enough water is given to prevent the leaves from withering. To force these plants to bloom throughout the winter months, cuttings can be inserted from March to May, and when well rooted, they should be potted in 3-inch pots and, later, in 5- to 7-inch pots. The tip of the main shoot and the side branches should be pinched out. They are then allowed to grow unchecked, except that all the flower buds should be removed until the end of September. From June to September, they should be set outside and buried to their rims in a bed of ashes or sand in a sunny spot so their shoots will ripen. Keep the soil moist and add a dilute liquid fertilizer once a week. Near the end of September they are placed in a sunny window or greenhouse with a minimum temperature of 50 degrees. Daytime temperatures shouldn't exceed 55-60 degrees. They will produce flowers continuously throughout the winter. In the spring (whether they have been forced to bloom throughout the winter or not) the branches are pruned back to ensure bushy growth. If pruning is neglected, they will become spindly and leaves and flowers will only be produced at the ends of the shoots. When new side shoots begin to grow, they should be taken out of their pots and all the crocks and loose soil should be removed. They are set in pots that are two sizes larger and the compost is made firm with a potting stick. For harvesting leaves of the Scented-Geraniums, begin pruning to keep the plants in shape once they are large enough to spare a few leaves. Use the leaves fresh, or dry them in a dark, airy room. Cut the plants back heavily before moving them indoors. Zonal Pelargoniums can be grown as standards (in tree form). This is obtained by inserting cuttings in August and September. When they have grown roots they should be potted in 3-inch pots and when they fill these up with roots, 5-inch pots, and subsequently in 7-inch pots. The main stem is allowed to grow straight up, but the side shoots are pinched out immediately. When the main stem in 3-4 feet tall, the tip is pinched and three side branches are allowed to grow. When they are 6 inches long, they should be pinched so a head of branches forms. Ivy-leaved Geraniums can be planted in hanging baskets. Line the baskets with moss and fill them with compost; then place Ivy-leaved Geraniums (that are well rooted) in the baskets, 6 inches apart, in April. Water them well and keep them in a greenhouse until the end of May or early June. They are then ready to hang outside. For the greenhouse or window, they can be planted in 6-inch or larger pots and the shoots can be tied to a central stake or a tripod of sticks that are stuck in the pots. These plants can be planted outside in May or early June, and as the shoots develop, they are pegged down in the soil. This way, the ground will be thickly carpeted by their foliage and the flowers will be shown off better. The general care and soil requirements are the same as with Zonal Pelargoniums. P. endlicherianum, the herbaceous Geranium, needs to be planted in well-drained sandy soil in a fairly mild climate. Succulent species of Geraniums should be planted in pots of very porous soil with adequate drainage. An addition of broken limestone to the soil is beneficial. They flourish in full sun and need a lot of water during their growing season. Normally they drop all their leaves in the winter, so they should be kept pretty dry until signs of new growth become apparent. The best growing conditions for these plants are windows in cool rooms or cool, airy greenhouses.

Propagation

Zonal Pelargoniums: Cuttings may be inserted in late summer or in winter; the summer ones (taken in August or September) create the best plants, however. A cut is made below the third or fourth joint, and only two leaves are left at the apex. All flower buds are removed, as all the stipules (small leaflike appendages at the base of the leafstalks). The cuttings are then laid on a bench in a dry atmosphere to allow a corky skin to form over the cuts. This prevents them from rotting. They are then inserted in a bed or pot of firmly packed sand in a greenhouse or under a bell jar in a window. Keep the sand moist but not soaked. Enough ventilation is provided to keep the atmosphere from being too humid and stuffy. When they have formed roots, 2 inches long, they are potted in 3-inch pots. When they are well rooted, they're gradually hardened off and planted outside in May or June. Pinch the tips of the main shoots to encourage bushy growth. Ivy-leaved Geraniums are propagated in the same ways as the above Geraniums.
Show Pelargoniums: In July, the stems of the old plants are cut back to three or four buds and they are sprayed occasionally to induce the growth of new side shoots. When they are 2 inches long, they are detached and planted in pots of sandy soil. They're placed in a cold frame in a moist and shady area. When they've formed roots, they are potted in 4-inch pots and placed on a shelf near the glass in a greenhouse with a minimum winter temperature of 45-50 degrees at night. Don't water the soil until it becomes fairly dry, and throughout the winter the same method is continued. In January, the plants are repotted in 5-inch pots. The tips of the main shoots are pinched out and as the pots fill up with healthy roots and the days lengthen, increased amounts of water are given. Weekly applications of dilute liquid fertilizer should be given from March until the flowers open. After flowering, they should be set in a sunny spot. From then until they are pruned, only enough water is given to keep them from completely drying up. They're pruned in July and either repotted in larger pots or the side shoots can be taken off and used as cuttings.
Both Zonal and Show Pelargoniums: Both of these kinds can also be increased by seeds. They are sown in sandy soil in the spring or summer and placed in a warm greenhouse to sprout. The seedlings are then pricked out and planted in a seed pan, 1 inch apart. Before they are overcrowded, they are potted in 3-inch pots and subsequently in larger pots. Seeds often germinate irregularly, so don't throw out the seed pots or pans from which a few seedlings have been taken until they are inspected for more. When the seedlings bloom, the best kinds should be noted, and increased by cuttings, since they do not come true from seeds.
Herbaceous Pelargoniums: These can be increased by division or seeds. Seeds can be sown in well-drained pans of sandy soil, which is moistened and covered, with a pane of glass. It is then set in a cold frame until they sprout. The glass is removed and when they're large enough to handle, they are planted in a seed box, watered, and shaded from sunlight until they're established. After they are hardened off, they're planted 6 inches apart, in a sunny bed and finally transplanted into their permanent positions in the spring.