Growing Geraniums 1/2

Pelargoniums or also geraniums (lat. Pelargonium) are well-known and very popular flowers that we plant in pots, bowls, boxes indoors, as well as in garden beds. Pelargonium flowers bloom throughout the entire growing season and look very decorative.

Pelargoniums were created by crossing original species that originate from the semi-steppes and mountain regions of South Africa. About 230 species of pelargoniums are currently known, more commonly referred to as geraniums in our region. For example, trailing double-flowered geraniums, upright geraniums, etc.

Geraniums began to be bred already in the last century. Breeding goals differ among individual groups of geraniums. Generally speaking, however, the aim is to improve the characteristics and traits of individual hybrids and cultivars of geraniums related to their flowering, growth, and disease resistance. Differences can be found in the shape, color, fullness, size and durability of flowers, as well as in height and branching of stems.

In our region, red geraniums have historically been decorations of small, humble country cottages, because the geranium plant is a symbol of friendship between the poor and the rich, as well as an expression of love.

Ideal Conditions for Growing Pelargoniums

Brightly colorful geraniums can be grown from seeds, which we plant in substrate made from a mixture of peat and mineral soil. The pH of the substrate should be around 6-6.5. Approximately 10 days after planting, geraniums are transplanted into small peat pots, and about 6 weeks after planting, we plant them into final containers with a diameter of approximately 100-110cm.

The ideal temperature for their growth is 20-22°C. Once young plants are rooted, a temperature around 18°C is sufficient for their further development. If the temperature drops below 10°C, pelargoniums stop growing.

Among the general conditions for growing geraniums, I can include their high light requirements. Flower production depends on the intensity of sunlight and day length. With insufficient light, geraniums grow significantly slower. Pelargoniums like plenty of sunlight. It's not good for the geranium plant to be exposed to excessive solar radiation, so we don't grow them in non-ventilated greenhouses.

For favorable plant development, appropriate watering is necessary. Be careful, overhead watering can cause the spread of bacteriosis in pelargoniums. Diseases can occur and spread among geraniums due to insufficient distance between individual plants.

Geraniums and Their Hybrids

With the arrival of spring and warm weather, pots with colorful, very decorative pelargoniums appear in windows and on balconies. Among the most commonly grown geranium hybrids are:

• Zonal Geranium (lat. Pelargonium zonale) is a very important hybrid with a large number of cultivars that differ in size, color, and fullness of flowers. Differences can also be found in growth characteristics. This geranium hybrid is characterized by flowers of various colors ranging from red through purplish-red, pink, salmon to white. The shape of its flowers is either single or double in various sizes. According to growth habit, we divide zonal geranium hybrids into low, medium, and tall varieties. These hybrids are characterized by their ease of flowering and their undemanding growing conditions, making them suitable even for growing directly in garden beds. It is also suitable for balcony cultivation because it grows upright, has velvety leaves, and very colorful flowers.

• Ivy-leaved Geranium (lat. Pelargonium peltatum) has a lower number of cultivars, and its importance is less than that of zonal geranium hybrids. The hybrids have simple pink flowers such as Ville de Paris, while other ivy-leaved geranium cultivars have double flowers such as Dresdener Dunkle Amethyst (purple flowers), El Agucho (red flowers), Galilee (pink shade flowers). These geranium hybrids have similar cultivation requirements as the previous hybrids. They have glossy, firm, and ivy-like leaves. They thrive best in hanging planters.

• Regal Geranium (lat. Pelargonium grandiflorum) differs from previous hybrids in its use and environmental requirements. Its breeding began over 100 years ago. The most widespread cultivation is of red-flowered cultivars, as well as salmon or white ones. After sowing, these cultivars take up to 60 days to form flower buds at an average temperature of 15°C. For further successful flower development, a day longer than 12 hours is required. These geraniums usually begin flowering at the end of April or beginning of May. The flowering of these cultivars can be accelerated by one month by exposing the plants more frequently to low temperatures and limiting their watering. However, it is important to note that plants can only be exposed to lower temperatures after they have rooted. When fertilizing regal geranium cultivars, it is important to keep in mind their high sensitivity to salt content. They are suitable for growing both indoors and outdoors.

Geranium flowers have a pleasant fragrance and contain geranium oil in their trichomes, which is very similar to rose oil. Geranium oil (lat. Oleum geraniol) is a suitable raw material for the pharmaceutical and cosmetic industry. Larger geranium plantations were established in France, Spain and Algeria to meet the needs of this industry.