Eucalyptus gunnii 'Cagire' AZURA Gum tree, Cider gum

In 2006, a miracle occurred that at first looked rather ominous – in a French nursery, all seedlings of this botanical species froze except for a single plant, even though everyone was convinced of its suitability for the French climate. One eucalyptus, one pot, survived an unusually severe winter that affected all of Europe that year. It showed great stability and an ability to be propagated, giving us the chance to enjoy the unmistakable beauty of steel‑blue leaves in Central-European gardens all year round. This exceptional individual was named AZURA and is protected by European patent No. EU 25846 from 2008. It comes from the French company Institut Technologie FCBA, which ensured that enough plants became available across Europe.

Today we can calmly confirm that AZURA is the first reliably hardy eucalyptus cultivar for zone 6 and warmer. It bears magnificent steel‑blue to blue‑green, evergreen, rounded leaves on upright branches covered with a silvery bloom. The leaves produce aromatic essential oils not only when crushed, but in warm weather they scent the surrounding air as well. The luminous blue‑silver foliage stands out beautifully against any greenery and in front of any material – wooden fences, stone walls or brickwork – and in winter, when part of the chlorophyll, the green pigment, recedes from the leaves, the blue colour becomes even more intense. Traditionally, the essential oils in the leaves are said to repel biting insects, but you would need an entire avenue of trees to drive away mosquitoes in their strongholds, so against mosquitoes I recommend using window screens – and I suggest using eucalyptus solely for its beauty 😊.

As for the size of AZURA, it is fair to say that we are sailing into uncharted waters. All previous ideas about how large Eucalyptus gunnii can grow in cooler climates (Central and Northern Europe) are based on non‑hardy plants that lost something every winter – the leader, branches, sometimes the entire above‑ground part. If frost ceases to be a limiting factor, as seems to be the case with this cultivar, it makes sense to expect a completely different scenario. Healthy, well‑established plants grow very fast, easily around one metre per year, and there is no reason to assume that their height should stop at the previously quoted figures of around four to five metres. Although this is still an expert estimate based on experience and growth logic, it is already clear that AZURA is vigorous and not inclined to stop easily. So, if the botanical species has the capacity to reach around ten metres, there is no reason to believe that AZURA must remain smaller. But don’t worry if that feels like too much – its growth is fully under your control. Spring pruning after frost keeps it compact, dense and shrub‑like, while leaving it to its own devices allows it to grow more freely and eventually develop into a taller, multi-stemmed or tree‑like form. It is entirely up to you how much space you give it and how you want its story to unfold.

Eucalyptus loves full sun, but it will grow almost anywhere. It likes moisture yet once established it can cope with summer droughts. It is not particularly demanding in terms of soil, although the ideal substrate is slightly acidic, fertile and well‑drained, but not completely dry in winter – it dislikes dry, black frosts. Usually, it is enough to check the soil once a month and give it one or two watering cans of water depending on the size of the plant in dry winters. It is best grown with a generous mulch. Fertilising is not necessary, and excessive feeding can lead to overly lush, whippy growth. The ultimate frost hardiness has not yet been tested in all conditions, but –20 °C has been verified, with an expected tolerance of at least –23 °C. And if you live in a colder area, don’t be discouraged – just give it a try; who knows, you might be the next to experience the thrill of discovering something new 😊.

Last update 11-10-2019; 22-01-2026