How to plant geraniums: when, where & how
Here you can learn everything about planting zonal and trailing geraniums, the optimal location and the suitable accompanying plants that can be cultivated alongside geraniums.
Geraniums, also known as crane’s bills or pelargoniums (because of the botanical name of these plants – Pelargonium) are one of the most common balcony plants. In spring, balconies are swarmed with a sea of geranium flowers. About 250 different wild species belong to this genus of plants. Originally, most geranium species come from sunny South Africa. The non-hardy perennials grow as semi-shrubs or shrubs and reach different heights. Intensive breeding has resulted in a large number of cultivated varieties that come in a range of different colours and growth forms. Currently, the most important of these cultivated species are Pelargonium zonale hybrids and Pelargonium peltatum hybrids.
Zonal vs. trailing geraniums
The growth form of the geraniums influences the choice of the location and the appropriate plant container. This step will ultimately decide the plant’s well-being. In general, geraniums can be classified as either trailing geraniums (also referred to as ivy-leaved geraniums; Pelargonium peltatum hybrids) and zonal geraniums (Pelargonium zonale hybrids), which grow in an upright way.
Zonal geraniums, the upright-growing kind, are evergreen semi-shrubs that grow to a height between 25 to 40 centimetres. They are the definite number one among geraniums when it comes to variety. This group is best suited for balcony containers and flower tubs. They do well when grown outside in garden beds, too. A truly one-of-a-kind subgroup of zonal geraniums are the regal geraniums (Pelargonium grandiflorum) also known as Martha Washington geraniums. They have numerous, impressive flowers, but they must be protected from rain.
Trailing (ivy-leaved) geraniums
Geraniums with a drooping growth, the trailing type, grow up to 30 centimetres tall and can form overhanging shoots over 150 cm long. Owing to these overhanging shoots, these types of geraniums are the nobility amongst balcony plants. They are the perfect perennials for balcony pots, hanging baskets or vertical gardens. Robust, single flowering varieties such as the ‘Cascade’ series or the well-known pink ‘Ville de Paris’ are especially gorgeous.
Fragrant geranium varieties & geranium oil
Many gardeners are interested in growing a special type of geraniums, the fragrant varieties. These scented varieties tend to have less splendid blossoms which they compensate with their delightful scent. Some varieties will surprise you with the uniqueness of their aroma. For example, while the aroma of ‘Chocolate Peppermint’ is reminiscent of chocolate, ‘Purple Unique’ reminds some gardeners of wine gums. Although these types of geraniums are arguably not as impressive in terms of their flowering abilities, their value lays in their leaf extract.
Geranium oil extracted from certain geranium varieties is used in perfumes, cosmetics, aromatherapy and is said to have a relaxing effect on the muscles. In addition, some fragrant geraniums help repel mosquitoes due to their strong aroma. These plants are therefore not only beautiful to look at but can even score extra points with their practical added value.
As their African roots suggest, geraniums are true friends of the sun and prefer a warm and sunny to semi-shady location. However, gardeners should mind the following: if possible, geraniums prefer to avoid full sun. A light breeze will not harm the plants, but their shoots can easily break in strong winds. As far as trailing geraniums are concerned, they should be protected from rain. In rainfall, their flowers stick together. Geraniums need cooler nights to flower continuously until frost. The more hours of sunshine per day, the more flowers are formed.
Best location for planting geraniums in summary:
- Warm and sunny to semi-shady location
- Sheltered from strong winds
- For trailing geraniums: pick a location with a cover from rain
The best soil for geraniums
For the cultivation of pelargoniums, a nutrient-rich compost soil or high-quality plant soil should be used. Many gardening centres supply a special geranium soil, which is also great because it is tailored exactly to the nutrient needs of these plants. It is particularly rich in nitrogen.
Planting geraniums: flower pots, containers & vertical cultivation
Choosing a planter for geraniums
The choice of planting devices is quite varied with geraniums – containers, flowers pots, hanging baskets – geraniums seem to feel comfortable virtually everywhere. Zonal geraniums can also be planted directly into the garden bed. A large soil volume is important for the development of the geraniums. Large pots or large balcony containers (20 x 100 centimetres) are the superior choice. Up to five specimens can be cultivated in such a way at once. The container should be at least 18 centimetres tall so that it allows for additional fertiliser and enough water to fit. Planters for geraniums should have a water drainage hole as well as a drainage layer (made out of expanded clay, for example) because these sun lovers do not appreciate excessively wet soil.
Trailing geranium varieties should be planted in taller containers or boxes so that they are able to unfold their full beauty. In order to make it easier for the trailing geraniums to develop well, it can be helpful to plant them slightly diagonally in the pot. However, make sure that their roots still have good contact with the substrate.
Planting geraniums in pots in summary:
- Use a large pot or a container (20 x 100 cm) for ~ 5 plants
- Height of the pot min. 18 cm
- Add a water draining holes or a good drainage layer (e.g. expanded clay) to avoid waterlogging
- Plant trailing geraniums at an angle to give their shoots more space
Geraniums planting time and repotting
Usually, the plants tend to be well-rooted and need to be repotted from their small plastic pots right after they have been purchased. Immediate repotting will encourage healthy and vigorous growth and an abundance of flowers to form. Once you remove the plant from the confinement of the old pot, make sure to loosen the root ball before moving it to a new and bigger home. This makes it easier for the plants to take root in the fresh soil. A definite sign that young plants are in a need of transplanting is when their roots start poking out of the bottom of the pot and begin to clog the draining hole.
Older plants should be repotted into fresh soil about every 2 years. To do this, carefully shake the old soil out of the roots and cut back the long, thicker roots and shoots of the plant by half. The pruned back geraniums should then be potted back into the cleaned old pot with some fresh soil. You can use the cut off shoots as cuttings to propagate your geraniums.
Although you can repot your geraniums throughout the year, the best time for repotting geraniums is without a doubt spring. From the end of February, the plants repotted in fresh soil can be kept in a bright yet cool place, such as a window sill. In colder regions, geraniums should move back outside and into specialised geranium soil from mid-May onwards. Do not put the warmth-loving geraniums outdoors until you are absolutely sure that they won’t freeze.
When to plant geraniums and how to repot them in summary:
- Repot geraniums right after purchase
- Young plants: repot when their roots outgrow the pot
- Older plants: repot every 2 years
- Best time for repotting: spring, but generally possible all year
- Plant geraniums outside from mid-May in temperate climate zones
Growing geraniums as house plants
When grown as house plants, geraniums feel most at home in warm rooms. In a large pot on a sunny windowsill, you can enjoy their numerous flowers almost all year round, provided that they are cared for properly of course.
Geraniums & companion planting
This balcony classic can be grown as a stand-alone plant, but it works just as perfectly with other sun-loving balcony plants. What is essential to consider is the growth rate and the water requirements of the potential companion plant for geraniums. The neighbouring plants should match as best as possible. Here are some plants that are great as companion plants for geraniums: petunias, Calibrachoa, Bidens (Spanish needles), verbenas, euphorbias (Euphorbia hypericifolia), garden heliotrope (Heliotropium arborescens), lantana (Lantana camara), Mexican creeping zinnia (Sanvitalia procumbens), Swan river daisy (Brachyscome iberidifolia), garden lobelia (Lobelia erinus) and rose moss (Portulaca grandiflora).