Tips for renewed flowering vigour. How to get geraniums back on top form

April 2023 Geraniums are everywhere in summer. No wonder, because this plant is a real flowering phenomenon. Few other summer flowers bloom so profusely, in such a variety and for such a long time, yet at the same time are so low maintenance. Sometimes the flowering enthusiasm of this beautiful native of South Africa suddenly diminishes over the course of the season. The experts at Pelargonium for Europe (PfE) suggest possible reasons why and give tips on how to get supposedly ‘lazy’ geraniums back to their best.

Removing faded flower heads is a real boost for more flowering, as it prevents the geraniums putting energy into forming seeds. They prefers to invest the energy they save into producing new flowers. There are self-cleaning geranium varieties for those who don’t like deadheading. They shed wilted flowers of their own accord. You should still remove withered foliage by hand, though.

If geraniums only have a few flowers, this may be due to a lack of nutrients. As ‘greedy’ plants, they have a high nutrient requirement. If you didn’t use a slow-release fertiliser when planting, the reserves in the potting compost will be depleted after four to six weeks and you should start fertilising. To fertilise, either mix a commercial liquid fertiliser for flowering plants into the water once a week or insert fertiliser sticks into the soil. These will last for about two to three months.

Geraniums are light-loving flowering plants. The more sun they get, the more abundant their flowers will be. So our experts recommend checking the location if flowering starts to decline. Are they still getting enough light? Especially near fast-growing shrubs or grasses, a formerly sunny spot can turn into a shady one within a few weeks. If so, simply move your geraniums to a sunnier spot.

Geraniums grow quickly. For this they need sufficient space. Four to five litres of soil per plant is necessary for them to develop properly. If there is less, their flowering ability suffers. If the space has become too small for your plants, repotting is the only solution.

As a guide: a 60cm x 20cm balcony box can hold a maximum of three geraniums, a 100cm box can hold four to five plants. A pot for a single geranium should have a diameter of 20-25cm and be at least 18cm high.

Tip: Alternating trailing and upright geraniums in a container gives the plants more space to develop freely.

Detailed advice on all aspects of geranium care is available at specialist retailers.