Room to grow

Geraniums flourish particularly well when given plenty of space. If the planter is too small or there isn't enough space between plants, they cannot grow properly. A minimum height of 18 centimetres is recommended for flower boxes and planters. Leave at least 20 centimetres between plants when setting.

A warm sunny spot

The geranium's original natural habitat is the Cape region of South Africa. With lots of sun and mild temperatures, geraniums growing there all year round have developed an impressive diversity of species. In our local temperate latitudes, on the other hand, outdoor geraniums only experience favourable growth conditions in the frost-free months from May to October. The geranium feels right at home in warm locations with at least partial to full sun. With a sufficient water supply, geraniums can even withstand intense and persistent heat.

Sufficient water

Profusely flowering geraniums require sufficient water. On dry, hot summer days it can even make sense to water them twice a day. Whether a plant needs water or not can easily be determined by carefully pressing a finger into the soil. If it feels dry down in the deeper layers, it's time to water. The right amount of water depends on several factors. As a rule of thumb, around ten percent of the pot's volume should be added in water every time. That's equal to about half a litre for a single plant in a pot 20 centimetres in diameter. It's important that any excess water must always be able to drain off to prevent waterlogging. As dry potting soil cannot absorb water very quickly, it should be poured slowly and not in one big gush. By the way: Even if geraniums flower most profusely when watered regularly and generously, they will not sustain permanent damage during brief dry spells, unlike many other summer flowers.

Sufficient nutrients

The geranium is a plant with high nutrient demands, which means that it requires constant feeding. To ensure that the plant gets all it needs right from the start, pre-fertilized geranium substrate should be used when setting the plants. Alternatively, slow-release fertilizer can be mixed in with the soil or plant food can be added when watering. Tip: The nutrients in pre-fertilized potting substrates are generally used up after a few weeks. After this time, the plant needs to be fed on a regular basis, for example, with liquid feeding. When using slow-release fertilizers make sure to read the directions on the label. For geraniums it is advisable to use a product that supplies nutrients for up to nine months. The time period of "9 months" is important as it is specially formulated for moderate temperatures of around 20° C. If the average temperature is higher, which can easily be the case in balcony boxes in summer, this fertilizer will be depleted sooner. If the fertilizer has a release period of only 5 to 6 months there is danger of the nutrients being depleted before the end of the season.

Pruning and cleaning

Regular removal of spent flowers, leaves and dried shoots - so-called deadheading - keeps a geranium healthy and stimulates flower formation, which results in additional flowers. To do this, pinch the withered flower stem near its base between your thumb and forefinger and twist it off. Deadheading is more essential for semi-double and double flowering varieties than the single flowering kind. If you find this to be too much work, you can rely on "self-cleaning" cultivars instead, for example, "Ville" or "Decora" geraniums.