- 19.01.2023 /
With their colourful, varied flowers, geraniums are a feast for the eyes. In balcony boxes, containers and flower beds, these easy-care plants create a summer mood and positive vibes. If you follow some key planting and care tips, these native South African plants will show their gratitude by putting on their best show from spring right through to autumn. The experts at Pelargonium for Europe (PfE) share how geranium lovers can be guaranteed a blooming miracle.
The ideal time
Experts recommend not planting geraniums outside before mid-May. This is because frosty nights are still possible in northern European latitudes up until this time. This can be fatal for these heat-loving plants. If it gets cold again after you’ve planted out your geraniums, there are ways and means to protect them from damage. For more information, see the geranium blog at www.meine-geranien.de.
The ideal soil
Fresh compost is important to get geraniums off to a good start. When buying, always look for the best quality. Special geranium compost is optimally adapted to the needs of the plants. High-quality compost for balconies and potted plants or universal potting compost will also do the job. Good compost has a high drainage and water retention capacity. It gives the plants support, while still allowing enough air to reach the roots. You can recognise a good brand by its pleasant earthy smell, loose consistency and additives such as clay and perlite.
The ideal drainage
Geraniums don’t like being waterlogged. Excess water must be able to drain away. In addition to high-quality compost, a layer of clay shards, expanded clay pebbles or similar materials on the bottom of the planter ensures drainage, because it prevents the compost from blocking the water drainage holes. Simply add it when planting. Tip: if you’re using a box with a built-in reservoir, a drainage layer isn’t usually necessary.
The ideal distance
In addition to a suitable container and a high-quality growing medium, the right distance from the neighbouring plant is important when growing geraniums. They should be at least 20cm apart. This means in a balcony box 60cm long x 20 cm wide there is room for a maximum of three geraniums, while in a 100cm box there is room for four to five. A pot for a single geranium should have a minimum diameter of 20cm. Tip: Alternating trailing and upright geraniums in a balcony box allows the plants to develop more freely.
The ideal location
Geraniums are sun-loving plants. The more light they get, the more abundant the flowers. They prefer a full sun location, but can also cope with partial shade. Varieties with large or double flowers also appreciate a spot protected from strong winds and rain, for example against the wall of a house or under a roof.
Geraniums need plenty of water to keep producing new flowers. On hot, sunny days, you may even need to water them both morning and evening. The water should be as warm as possible and you should apply it directly to the soil, rather than the plant itself. Balcony boxes with reservoirs or your own homemade automatic watering system reduces watering time considerably. Tip: Even on rainy days you may need to water. With bushy plants, the raindrops often don’t even reach the soil.
Geraniums are ‘hungry’ plants that need a lot of nutrients. If you’re using pre-fertilised potting compost, you should re-fertilise it after four to six weeks, as its stores will have been depleted by then. For an ideal supply of nutrients for geraniums, just mix a commercially available liquid fertiliser for flowering plants into the water once a week. Alternatively, fertiliser sticks can supply the plants for two to three months. A slow-release fertiliser will even provide enough nutrients for up to nine months. You can add it to the soil later if you didn’t do so when you planted the plants.
Geraniums look more attractive, produce more flowers and stay healthier if you remove faded flowers and wilted leaves regularly. If you don’t want to do this, there are self-cleaning varieties of geranium available. These shed their faded flowers automatically making them bloom more readily. However, you will still need to remove withered leaves from these geraniums manually.
To overwinter geraniums, cut them back to about 15cm before the first night frost and move them to a bright, cool place. This can be a frost-free garage or a similarly cool place indoors. During this winter dormant phase, they need very little water. In spring, cut them back again, repot them in fresh compost and place them in a warm spot.
Detailed advice on all aspects of geranium care is available at specialist retailers.
Reproduction is free of charge with the credit “Pelargonium for Europe”. Further texts and images can be found at www.meine-geranien.de.