Geranium Rozanne, magnificent ground cover

Geranium Rozanne

Geranium ‘Rozanne’ is a variety with one huge advantage: it’s a perennial. It resists freezing while maintaining incredible ornamental value.

Geranium Rozanne facts

NameGeranium ‘Gerwat’
Trademark – Geranium Rozanne™

Type – perennial
Height – 16 to 20 inches (40 to 50 cm)
Exposure – full sun, part sun

Soil: ordinary but well drained  –  Flowering: May to October

Ideal for ground cover and well suited to growing in pots or pot arrangements, geranium Rozanne also offers a very long-lasting blooming.

Planting the geranium Rozanne

Preferably in fall or spring in a mix that includes geranium-specific soil mix.

Planting geranium rozanneSpace plants around 8 to 16 inches (20 to 40 cm) apart.

  • The Rozanne geranium fears moisture more than it does cold.
  • It loves full sun to bloom as long as possible in an abundant burst of colors.
  • Propagate through crown division in fall.
  • It’s also possible to start new plants from cuttings.

Since Geranium Rozanne is a sterile hybrid, it will never produce seeds.

  • Not having any seeds is an advantage. If it did grow seeds, it would spread and probably turn invasive because it is very hardy and resilient!

Pruning and caring for the geranium Rozanne

Mounding Geranium Rozanne with wood chip mulch.The geranium Rozanne requires next to no care, like other perennial geranium.

Cut back stems eventually after they have flowered in order to trigger production of new flowers and avoid draining your perennial geranium.

Pruning Rozanne ‘Gerwalt’ Geranium

This pruning will also keep your Rozanne from getting leggy and spreading too far: cut branches back by half to trigger new branching out. You can do this in any season, but there are differences:

  • in fall and winter, go ahead and cut them all at once
  • in spring and summer, cut back the longest ones only. Wait for new growth to appear on them. When leaves have opened up on the branches you’ve pruned already, go ahead and prune a few more of the remaining longer ones by half. Repeat until you’ve shrunk the entire bush.

As resistant to diseases as it is hardy, no known disease seems to infect geranium Rozanne.

Geranium Rozanne in winter

Leaves and smaller stems will die back with the cold.

  • Cut them off or remove them delicately.
  • Mulch the base with free-breathing plant mulch such as dead leaves.
  • In spring, new shoots will appear.

Geranium Rozanne in summer

For sustained blooming, water often but make sure excess water drains out.

  • Heat and high temperatures aren’t a problem for this Geranium variety.

Learn more about the geranium Rozanne

This perennial is among the most abundant flower-bearing geraniums. More than anything, it is among those that bloom over the longest period. Indeed, the blooming extends from May up to the first fall frost spells. It can withstand summer heat.

Care, heat resistance and water needs are identical to those of Sunpatiens, another great sun-loving flower.

In a flower bed and also along edges and in rocky ground, geranium Rozanne can serve as excellent ground cover (like the Patricia geranium) and beautiful garden box items.

History of Geranium Rozanne

Geranium Rozanne was first bred and discovered in 1989, by Donald and Rozanne Waterer. They were growing several dozens of Geranium plants which Rozanne loved. One year, a particularly vigorous specimen appeared in their garden in Somerset in the United Kingdom. It flowered profusely the next year from spring to first frost. Rozanne had never seen such a bloom! Parent plants were Geranium himalayense and Geranium wallichianum.

The couple was already familiar with horticulture, since Donald had been born and raised in a family that loved gardening (they had bred many hardy azalea varieties in their heyday). He had managed it and this discovery came after he had retired. They got in touch with flower expert Graham Stuart Thomas.

Graham Thomas was already famed for his work on preserving old English roses heritage breeds. He guided the Waterers towards Adrian Bloom (of Blooms of Bressingham), a well-known horticulturist. After propagating, growing and testing the plant, they were able to patent it as a new development!

Two single Geranium Rozanne flowers with clear white center, purple petals and violet petal veins.Thus the plant was originally protected by a plant patent. The botanical name is actually “Gerwat”, which stands for Geranium and Waterer. “Rozanne” is the trademark name that the plant was marketed under, in honor of Mrs. Waterer.

After 2 decades, this patent has expired in February 2019 (for the United States and GATT signatory countries). It’s now allowed to propagate your own, and even sell them!

It’s a beautiful example of how a passion for flowers can spread the world, since millions of specimens have been sold throughout the world.

Smart tip about geranium Rozanne

You can provide it with geranium-specific organic liquid fertilizer once or twice in the season to increase blooming.

Also, Geranium Rozanne prefers slightly acidic soil rather than alkaline soil, so a good mulch to use is pine bark mulch or even coffee grounds.

Images: 123RF: WDNET, CC BY 2.0: Arend Vermazeren, CC BY-SA 2.0: F. D. Richards, Fr. Ted Bobosh