Pelargoniums

One can fill pots and barrels with bush and king pelargoniums, and fill hanging baskets and window boxes with ivy-leaved pelargoniums. Bush pelargoniums that flower throughout the year can also be used to replace annuals in flower beds. Many hybrids, especially of the ivy-leaved pelargoniums and the lovely Pelargonium reniforme, are ideal for the cavities in retaining walls and as a ground cover in dry, hot and sunny areas. The rose-scented Pelargonium graveolens and the lemon-scented Pelargonium crispum have exceptionally aromatic (and edible) leaves and are ideal for planting along a garden path and in herb gardens.

When do Pelargomiums bloom?

Most modern varieties flower repeatedly throughout the year. The most prolific flowering occurs in spring and again in autumn, when temperatures are more moderate.

Most suitable climate for Pelargoniums

Some pelargonium species and hybrids are hardier than others and can endure light frost and cold, but in these conditions, they can be semi-deciduous. If this happens, a light pruning in spring will quickly bring back the leaves and flowers. In very cold regions, these plants either have to be treated as annual summer colour, or they must be planted in a sheltered area. The most suitable climates for pelargoniums are temperate to warm and dry. They also flourish in coastal gardens, although in the subtropical areas with high humidity and high rainfall the incidence of fungal diseases increases.

What Pelargoniums need

Location: full sun, and light shade such as the bright natural light on a veranda or patio.
Soil: these plants hate wet feet and soil that does not drain properly. In containers, quality potting soil is sufficient, and in the garden the soil must be enriched with compost. Improve the structure of clay soil by working in some coarse river sand.
Water: the plants are medium to low water consumers. Allow the soil to dry out completely between watering. In warmer weather, container plants require more water than those in the garden.
Fertilizing: pelargoniums are greedy plants and in the absence of regular feeding they can cease to flower. Feed garden plants during spring with a slow-release fertilizer such as 3:1:5 or an organic equivalent, then repeat every six to eight weeks until early autumn. Feed pot plants every two weeks with liquid fertilizer.
Pruning: deadhead spent flowers regularly and prune during spring and again in autumn to remove any excessive growth and to keep plants bushy and dense. (The growth habits of bush pelargoniums, in particular, tend to be lanky.)

Get more value

Cuttings can be used to propagate new plants. First take cuttings, about 15 to 20 cm long, and remove all but the last pair of leaves at the thin end of the stems. Dip the stems in commercial growth hormone and plant in pots filled with a mixture of coarse river sand and vermiculite or fine pieces of bark. The mixture has to drain well and be kept just moist. Keep the cuttings in the shade until they have developed a good set of roots. At that stage you can feed with a water-soluble growth stimulant to promote fast, lush growth.

Pelargonium Pots

Our most beloved flowers, pelargoniums (also known as geraniums), spill from the shelves of garden centres at this time of year, and it takes a really strong heart not to fall in love with them all over again! The ivy-leaved pelargonium (Pelargonium peltatum) is normally described as a climbing, semi-succulent perennial that is used extensively in horticulture. What this description doesn’t say is that they give superb flower power in window boxes, hanging baskets and containers. Thousands of pelargoniums are grown each year and new varieties appear regularly.

A stunning pot combo

• We used two specimens of the new, early flowering ranges of pelargoniums, namely ‘Marcada’ and ‘Tacari’, with a selection of other champion plants in our pot. These pelargoniums are very floriferous, self-cleaning, have a high resistance to weather conditions, and need less water than other P. peltatum varieties. They have compact growth habits that maintain a neat shape, and carry their large and showy flowers above the plant’s canopy.
• Marguerite daisies go with anything, and in here we used Argyranthemum ‘Madeira’ Deep Pink. The ‘Madeira’ range consists of upright, mounded plants with long-lasting flowers in repeated flushes.
• If spot-fillers are needed, call on lobularia (alyssum), and more specifically Lobularia ‘Stream’ Lavender and ‘Stream’ Raspberry. The rich shades of lilac to purple and darker pink complement the bright pinks and reds of the other pot dwellers quite well. They form densely mounded flower cushions and stay in bloom for ages.
• Petunia ‘Amore Queen of Hearts’ is a bicolour petunia that displays five red hearts on each bloom, with a striking yellow contrast to complete the happy look. It has a semi-trailing and densely blooming habit that will dip nicely from containers and hanging baskets. The ‘Amore’ range of petunias holds up well to rain.

In a nutshell

• Bright colour for gardens and containers throughout the year.
• Medium to low water consumption.
• Hungry plants that require fertilizer regularly to produce flowers.

Some of our favourites

• Pelargonium grandiflorum, and the regal pelargoniums (king pelargoniums), are large, bushy perennials that grow upright with sharply serrated leaves. They produce large flowers in shades of white, soft pink, dark pink and purple. There are also many modern hybrids with lovely variegated flower faces that descend from Pelargonium cucullatum.

• Pelargonium peltatum (ivy-leaved pelargonium) is a spreading, creeping plant and its hybrids, are used as a ground cover and in hanging baskets, are considered to be the hardiest garden pelargoniums available. They are most resistant to fungal diseases such as rust, and flower in abundance regardless of poor soil, drought, light frost and even light shade. The leaves look very much like those of the normal ivy, except that they are fleshier and brittle.

• Pelargonium zonale (horseshoe pelargonium) is the most widespread species in the wild in southern Africa and has been used as the parent for many of the hybrids now available. The plants are dense and bushy and the leaves velvety soft. Depending on the variety, the leaves can be coloured in bright autumn hues or have creamy white and green patterns. The flowers are single or double, and colours range from snow-white to apricot, salmon, blood red, rose pink, dark purple and cherry red.

‘Elegance’ range

The ‘Elegance’ range is now available and comes highly recommended as offering bushy but compact evergreens with rippled dark green, tooth-edged leaves. The large and spectacular intricately patterned flowers are held on sturdy stems above the foliage and there is a varied range of lovely colours. Mature size is about 40cm high with a spread of 100cm.

Pelargonium grandiflorum ‘Elegance’ is suitable for tropical, subtropical, temperate and Mediterranean climates, and will tolerate cold but is unfortunately not frost-hardy. In very frosty climes it should be treated as annual colour or kept in a protected place.