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Hardy and Colourful Geraniums

These versatile plants are perfect for any sunny spot that calls for a splash of vibrant colour.

These versatile plants are perfect for any sunny spot that calls for a splash of vibrant colour.

Geraniums are easy to grow plants that fit well in home gardens, container gardens,  flowerbeds, and even as houseplants.

The plants generally known as gera­niums are in fact pelargoniums, and are indigenous to South Africa. They were taken to Europe during the 17th cen­tury, and by the end of the 18th cen­tury had become extremely popular. Today, after more than 100 years of hybridising, they are still favourites, be­ing adaptable, varied, and trouble‑free.

Home gardeners use Geranium plants in a wide variety of ways. They are well suited for container gardens by themselves or with other flowers. You can use them to make a potted gift for a friend for any occasion. They make excellent bedding and border plants, and look very attractive in containers and hanging baskets. When the weather gets cold these hardy plants will withstand light frosts and patiently await transplanting into containers to move them indoors. Smaller, dwarf varieties make the best houseplants. Geraniums like lots of sun.

Though in temperate climates most geraniums are grown as perennials, they are annuals in very cold climates. Bring them indoors to overwinter, if you like. They can bloom indoors all year long if they get enough light. Then replant outdoors in spring.

Although there are huge numbers of versatile hybrids, there are only a few main categories —

Zonal pelargoniums (Pelargonium xhortorum) These are the popular ‘bush geraniums’ that are found in many South African gardens. They grow well in beds and borders, and also in containers. The flowers range from tiny singles to giant doubles, in white and shades of pink, red, salmon, and purple.

The leaves are rounded and often marked with a horseshoe‑ shaped zone of darker colour. The new Fl hybrids are vigorous, disease‑resistant, and free flowering. They are available in many different shades, and some have white centres or ‘eyes’.

Pelfi geraniums, also known as floribundas, result from crossing an ivy‑leafed pelargonium with a minia­ture pelargonium. The plants are com­pact and have many small flowers.

Stellar pelargoniums have star‑shaped foliage, zoned or plain. The flowers are borne on long stems.

Ivy‑leaved pelargoniums (Pelar­gonium peltatum). This type is better known as the ‘creeping’ or ‘trailing’ geranium. The leaves of these plants are shiny and similar to ivy. The plants trail and climb, making them ideal as ground covers on banks and slopes. They are also very attractive in wall boxes and window boxes, and in hang­ing baskets. They are hardy and free­ flowering, with single, semi‑double, or double flowers.

Show or Regal pelargoniums (Pel­argonium x domesticum). These are gen­erally called pelargoniums rather than geraniums in this country. The flowers are usually large and marked with blot­ches, and are sometimes ruffled. The leaves are fluted, fan‑shaped, and hairy. The plants grow up to 1 m tall, and will withstand salt spray.

Scented‑leaved pelargoniums. Many of these seed and grow easily, and there are dozens of varieties with different scents to their leaves± they are primarily for their aromatic leaves with scents such as citrus, apple, rose or mint. These plants have smaller, less showy flowers than the other types. Citrus-scented cultivars, such as ‘Citronella’ are sold as mosquito repellent plants, although they are not very effective for this purpose. Heat brings the scent out, so these pelargoniums should be planted in warm positions and near paths where the foliage will be brushed by passers‑by and the occasional leaf can be picked.

Other types of geraniums: There are dwarf types that can be ivy‑leaved or regals, but are mostly zonals. They are small, bushy plants with large flowers. There is also and a group known as stellars, which have star-shaped flowers and notched leaves.

GROWING AND PRUNING THE PLANTS

Pelargoniums thrive in sunny positions, and will not flower if kept in continual shade, but they may benefit from a degree of shade in the summer.

They need a well‑drained soil, and should be mulched in summer. Use complete fertiliser or compost when preparing the bed, but avoid nitrogen ­rich fertilisers and excessive manure as these will encourage foliage growth at the expense of the flowers. Feed them at planting time with a time-release fertilizer that lasts all season. Regular fertilizing is especially important for container-grown plants.

Water: The key thing about watering geraniums is to water them thoroughly, but let the soil dry between waterings. Be sure to water the plants regularly when it doesn’t rain. Check containers daily during hot summer weather. The best way to do this is to use a water meter or poke a finger into the soil. If it’s dry two inches down or more, it’s time to water.

Grooming: Leaves can die and turn brown for a number of reasons, mostly because geraniums are quite sensitive to fungal disease from excess moisture and humidity. Keep your plants looking their best by deadheading them and removing dried or discolored leaves. Your geraniums will reward you by looking great all season.

WHEN AND HOW TO TAKE CUTTINGS

Use firm stem cuttings of the current year’s growth, about 10 ‑ 12 cm long, taken after the plants have finished flowering. Cut just below a node (leaf joint). Remove lower leaves but retain top leaves. Plant the cuttings around the edge of a pot filled with sand, or a mix­ture of three parts sand to one of peat, with the stems 4 ‑ 5 cm deep. Once they have rooted, plant them out or pot them individually. In frost‑free areas cuttings can be planted directly into their permanent positions.

In the past, most commercially grown plants were propagated from cuttings as described above. But advances in Pelargonium breeding have changed that. Now you get excellent seed-grown Hybrids and F1 hybrid varieties that outperform many older cutting-grown varieties.

Pelargoniums will tolerate a light frost, but in areas with heavy frosts, lift the plants, pot them, and keep them indoors through the winter.

Prune plants after flowering to keep them compact. Cut back vigorous stems by one to two thirds, cutting just above a leaf joint. When new growth appears, pinch out the tips to encourage branching.