Pelargonium Peltatum & Heat Tolerance
By Jeff Jones who lives in Kalgoorlie/Boulder
There are about five hundred different cultivars of Ivy Geraniums that have been hybridized over the last 150 years.
In this family of plants is a small group of long flowering plants with single flowers that cascade freely.

Cascade Geraniums have been extensively grown in Europe, in window boxes on balconies and in hanging baskets. Unfortunately, they cannot survive below freezing winters and are either taken under cover or replaced each year.
Picture
Ivy Pelargoniums in Miltenburg Germany
PictureAn old Pelargonium Peltatum
The normal European bred zonal or ivy in Kalgoorlie will stop flowering in mid-November and not start again until May.
Pelargonium Peltatum, the original species originated in South Africa which has a similar climate to large parts of inland Australia.
So they do not become dormant with the onset of hot weather, they flower throughout summer, daily temperatures out to 44 degrees centigrade  don't concern them. Their flowers stand up like soldiers and don't wilt, however a few days at 47 degrees C  they don't handle so well.

Where we live in Kalgoorlie Western Australia, we have some plants twelve to fourteen years old, because we don't have the problem of freezing winters.
Ville de Paris with its glowing orange/red flowers, in group plantings is a memorable sight.
This high performance cultivar can flower for nine to ten months year after year. This plant has few equals and creates a powerful colourful image.
Decora Rose.
This cultivar is an old favourite: in France it's displayed in urns at the Palace of Versailles, the Chateaus along the Loire Valley, and elsewhere.
The flowers when they first open are a dark pink, fading to a light pink as they age.
The two tone effect of complementary colours in Drum Planters is a pretty addition to any streetscape
Lilac Cascade.
As the name implies the flowers are lilac in colour, that is a pale mauve/blue.
Lilac is a restful colour in a streetscape, we have grown them in pale blue painted Drum Planters and these have attracted many complimentary comments. Long flowering, tough, no vices, what more can you ask?
Ville de Dresden
Heaps of white flowers, a vigorous plant that will stand, and needs, pruning.
Ville de Dresden can be planted with other cultivars, however it tends to take over.
Flower Power Ville de Dresden can be a strong addition to a streetscape, and provide variety.
There are another six or seven Cascading Geraniums that I don't have at this time. Most have been hybridised in the big German Nurseries.