For many years, geraniums have been the most popular flowering plant for beds and balconies. And with good reason: geraniums come in numerous colours and shapes. They grow quickly; flower abundantly and continuously from spring to autumn; and are low maintenance and hardy. You don’t need to be an expert for your geraniums to flourish. This plant also gives gardening novices a sense of achievement if they follow a few tips. The experts at Pelargonium for Europe (PfE) know exactly what’s important when planting and caring for geraniums.

When is the best time to plant geraniums?

As soon as the first warm spring days arrive, you might want to start planting out balconies and terraces straight away. But be careful with geraniums, as they don’t tolerate cold well. They should only be planted when nights are consistently frost-free and daytime temperatures are regularly above 10°C. If you just can’t wait, be prepared to protect your geraniums from cold, if necessary. For example, when the outside temperature is low, your plants will be better off on a windowsill, a rack on your house wall, or under cover, than on a draughty balcony railing or in a pot on the cold ground. At night, you can protect geraniums from frost with garden fleece, bubble wrap or a bed sheet. However, if it gets really cold again, you should temporarily place your plants in a sheltered indoor space. Conservatories, frost-free summerhouses or garages are suitable emergency shelters – ideally with natural light.

What should you consider when planting geraniums?

Whether in a balcony box, container, pot, hanging basket or bed, geraniums feel at home anywhere. Provided they have enough space. The distance between plants should be at least 20cm and the height of the pot should be no less than 18cm. When planting, use high-quality, pre-fertilised compost, remember to include a drainage layer and make sure excess water can drain away at all times.

What’s the ideal location for geraniums?

Geraniums are light-sensitive plants. The more sunlight they get, the more abundantly they bloom. To enjoy lots of flowers quickly, buy well-developed plants with plenty of buds and dense foliage. Geraniums are at their best in a full sun location. However, they can also cope with partial shade. Geraniums don’t like constant rain. Varieties with large or double flowers in particular like a protective roof over their heads on rainy days.

How do you water geraniums properly?

Geraniums can store a lot of moisture in their leaves and stems, so a few days without water are not a problem. However, they need regular watering to bloom abundantly. On very hot summer days, it’s a good idea to water them in the morning and evening. Reservoir window boxes and automatic irrigation systems can significantly reduce the amount of watering required. Tip: Rainwater or standing water is ideal for watering.

With bushy plants in particular, sometimes the moisture doesn’t reach the soil, even in rainy weather. To find out whether your plants need water, check the soil moisture with a finger. If the soil feels warm and dry, you need to water. If it rains continuously, experts recommend avoiding drip trays or pots in which water can collect, as geraniums don’t like to be waterlogged.

How do you fertilise geraniums properly?

Geraniums need a lot of nutrients. You should start fertilising them about four to six weeks after planting. By then, the nutrients have often already been used up, even with pre-fertilised compost. For optimum nutrition, simply add a commercial flowering plant fertiliser to the water once a week. Alternatively, you can use fertiliser sticks. These last for around two to three months.

If slow-release fertiliser was used when planting, you can leave more time before applying a top-up feed. Exactly how long depends, among other things, on the type of fertiliser used and the temperature and soil moisture. From late summer onwards, it’s not uncommon for geraniums to need additional nutrients even when fed with slow-release fertiliser. You can recognise a nutrient deficiency when your geraniums no longer flower properly or their leaves turn yellow, even though everything else is fine.

Remove faded flowers

Regularly removing spent flowers and leaves, as well as dead stems, keeps geraniums healthy and stimulates flower formation. Self-cleaning varieties, which are mainly found among trailing geraniums, shed faded flowers on their own and usually produce new ones straight away. However, withered leaves still need to be removed by hand.

Overwintering geraniums

Geraniums are perennials. If you want to overwinter them and have enough space, before the first night frost, cut your plants back to around 15cm and move them to a bright, cool place. Geraniums need no fertiliser and hardly any water in winter. In spring, repot your plants in fresh compost and place them in a warmer spot. With a bit of luck, they will sprout again.