Why are Rhododendrons such a beautiful flower for cutting?

Left: Rhododendron 'COS' enmass in a vase. Right: Table Centre piece featuring R. maddenii.

When you think about cut flowers, I bet you don’t immediately think of Rhododendrons. Here in Dunedin, the Himalayan natives grow so well and have become so much a part of our city's identity, that we have a Rhododendron Festival at our local Botanic Garden. We would be remiss not to include them in our floral design to contribute a scene of place and season.

October is the height of Rhododendron season here in Dunedin, but they have a wide flowering range and you can find species in bloom from July (such as ‘Rhododendron Christmas Cheer’) right through to December (sweetly scented R. ‘Kotuku’ and R. ‘Mi Amour’). Speaking of diversity, the range of flower colour is truly a spectacular rainbow to suit any posy or archway. 

Left: The beautiful and early flowering R. 'Christmas Cheer' in full bloom. Centre: R. 'Christmas Cheer' in a mixed winter bouquet. Right: R. 'Cunningham's White' is a favourite for picking due to its vigourous growth and long stems of straight growth.

Surely they don’t last in water, I hear you say? In fact, I have found if picked at the correct stage of opening and the right cultivars are selected, they can last in water for up to 10 days!The correct time to harvest, for the longest vase life, is when in coloured bud, or when just one or two flowers are open around a cluster of buds. They continue to open and bloom beautifully once picked, and the tender blooms are much less prone to bruising when in bud than when open. Alternatively, if you are using them for flowers at a particular event — where you want bang for buck and vase life isn’t the priority — you can pick them more open for impact on the day. However, take care to avoid creasing or crushing the blooms if they are open, as they brown easily - especially in the pale colour ranges, just like open lilies do.

Left: R. 'Starbright Champagne' is a favourite for picking. Centre: R. maddenii in mixed bouquets. Right: R. 'Kings Milkmaid' showing different stages for picking - coloured bud for the longest vase life, only a few buds open for bouquets, and fully open and great for events.

I have found, over the years, picking Rhododendrons, that a few rules of thumb as to the varieties you are picking are helpful. There is such a glorious diversity of flower size and shape — but I find more robust blooms, rather than the crepey ones, last better. In general, small to medium blooms are better for picking, as they work into smaller arrangements and seem to last a little longer with it. In a big installation, big blooms are bold and impactful though, so keep in mind that rules are made to be broken — the giant bloomed R. macabeanum would grace any large installation, for example! 

Left: R. ponticum hybrids are vigourous growers and prolific flowerers and great for cutting, just watch that new foliage and pick in mostly bud as the flowers are soft. Centre: R. 'COS' in a spring wedding bouquet. Right: R. loderii hybrids have an amazing scent and huge trusses of blooms.

Keep in mind the vigour of the cultivars you are picking from, as cutting the flowers removes significant growth. Though most Rhododendrons respond well to pruning, they do need time to become established before significant picking takes place, and always take care to prune to a growth node.

Avoid Rhododendrons that have soft fresh growth along with their flowers, or cut this off, as it has a tendency to wilt. Some also have significant sticky bracts surrounding the buds that turn brown and drop as the blooms open, which is not always a good look. As a bonus, once the flowers are spent and the foliage has hardened, they are very useful as foliage plants too! I especially value the beautiful lush green foliage in winter to give structure in an arrangement — I love the downward angle the leaves form, giving shape and movement. 

If I haven’t convinced you of their worth as cut flowers yet, just wait till you walk past R. maddenii or a R. loderii hybrid and catch a waft of the deep, sweet, fresh, but heady scent that instantly improves your mood. 

Rhododendrons are a truly versatile cut flower and foliage that lend a fresh,  lush look to any design, have such a diversity of flower shape, size, and colour, flower across a huge period,  and can be heavenly scented— what more could you want in a cut flower?

Left: Early spring bouquet ingredients, including R. 'COS'. Right: R. 'Starbright Champagne' in mixed arrangements, providing a larger form against the lighter blooms.