Geranium Growing Guide
Geraniums – also known as Pelargoniums – are one of Britain’s best loved flowers, and for good reason. Although it is important to remember that they are not frost hardy, geraniums are perennial, and so are a winning choice to provide splashes of Mediterranean colour to your garden for months on end. If grown inside or in greenhouses, these flowers can delight all year round. Famous for flowers which range from ruffled clusters against deep green foliage to small dashes of colour, these highly ornamental flowers have become so popular that there is even a national society – The Geranium and Pelargonium Society – dedicated to their cultivation up and down the country.
Geraniums are found in most abundance in the eastern Mediterranean region, which accounts for their sunny associations, but are native right across Europe and Asia. They have been with us a long time in Britain and are well adapted to our climate, able to grow in almost any soil.
Geraniums take their name from the Greek word for ‘crane’ and are so called because of their truly unique method of seed dispersal. In a true wonder of a nature, the geranium disperses its seeds from columns, which resemble the long bill of a crane and which spring outwards under pressure, casting the seeds an impressive distance from the plant. This amazing mechanism also gives rise to another common name for this flower – the cranesbill.
How to Grow
Planting
Geraniums are impressively resistant to heat and drought but will perish in frost. Accordingly, wait until the frost has safely past before planting your geranium. This will most likely be from March. The plant fares best under direct sunlight so choose an area with plenty of sun. It’s also a good idea to initially grow your geraniums in pots or cell trays in a warmer area until they’re substantial enough to be moved outside.
One of the most attractive features of geraniums is their adaptability to almost any soil. You do not need to fret much in this department, however, to optimise flowering, be sure to plant in a moist but well-drained soil.
Dig a good size hole in your soil, enough to accommodate the football with space to spare. Be sure to add some organic matter like compost around the root ball and plant so that the top of the root ball is level with the soils surface. It is then worth adding around two or three inches of mulch around the planting area to protect the roots, guard against weeds and conserve soil moisture.
Some varieties of pelargoniums can be sown from seeds. To have your geraniums ready for summer, it is worth planting seeds in mid-January in pots or trays of seed sowing compost and placing in a propagator. Be sure to keep the temperatures constant at 20-25°C. When the seedlings are large enough to be potted, transfer to the pots and thereafter keep the temperatures at around 10°C until they are ready to be moved outside after the frosts have passed.
Ongoing Care
Geraniums are not thirsty plants, so will not require regular watering. Simply be sure that the soil remains reasonably moist and water only when needed. In winter, water very sparsely as the soil will require time to dry out between each watering.
Apply a liquid feed every two weeks or so in spring before the plants are established. Once the flowering period begins, switch to a high potassium fertiliser like tomato food and apply with the same frequency. After the plants have been brought inside in winter, fall back on the feeding, as only sporadic watering and temperature maintenance will be required at this time of year.
Overwintering is vital for geraniums. Although perennial, drought and heat tolerant and adaptable to almost any time of soil, the flowers will perish in the frosts of a British winter, so be sure to move them into a greenhouse or indoors well in advance of the first frosts. The best way to do this is to take softwood cuttings in late summer and transplant to a container. Place this container on a well-lit indoor windowsill and maintain at 10°C. Apply some pruning in winter (see below) to encourage bushy growth and then replant in the spring. This method does require some forward planning, and it is worth bearing in mind that geraniums can simply be grown as annuals; you can still have several months of rich colour before simply pulling them up and adding to the compost pile in autumn.
Pruning and Training
In spring or early summer, geraniums can be pinched back to encourage branching. This will not need to be done particularly frequently – once or twice should encourage bushier growth.
If you are overwintering geranium cuttings, however, be sure to pinch out the shoot tips in late winter to encourage bushy growth. Applying this method and then doing so again once they are planted outside in the spring will encourage a voluminous bloom.
Diseases and Pests
It’s unlikely your geraniums will suffer from much pest damage. And any that you do notice can normally be manually removed. Generally speaking, however, nature will provide her own pest control. Natural predators like ladybirds and hoverflies should take care of any larvae or aphid damage, and for the rest there’s always birds.
Keeping your geraniums well ventilated and at a steady temperature should be all that’s needed to protect against grey mould and rust taking hold in the winter months.
Geraniums in Your Garden
An extremely versatile flower, geraniums are well suited to flower beds and borders, where they can contribute a voluminous spread of sunny colour, but are also well suited to containers. Being a perennial flower, the benefits of container growing really come into their own because it only takes a change of location to have these beautiful flowers brighten the dark winter months as well. With overwintering, however, even planted geraniums can be maintained in this way.
The variety of colour available from geraniums is a particularly attractive aspect. Maintaining similar flower shapes, you can creatively mix and match colours like pastel pinks, whites and purples as well as the deep reds of the larger ruffled species. These flower clusters grow on long stocks, creating a wide spatial distribution of flowers and an impression of volume. These long stalks are also striking drooping out of hanging baskets – another excellent way to grow geraniums.
Some varieties of geranium also feature scented foliage, a massive boost to any garden atmosphere. The foliage is normally rose or lemon scented and offers its distinctive aroma all year round.
Useful Links
- Dianthus Growing Guide (Article)
- Fuchsia Growing Guide (Article)
- Dahlia Growing Guide (Article)
- Lavender Growing Guide (Article)
- Shop online for bedding and patio plants
- Shop online for plants