Daffodils – do they kill other flowers?

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Spring is here, and daffodils are blooming. You might have some in your garden, or you might pick some up at a florist to put in a vase at home. If you do, it’s a good idea to place them in a vase on their own – there are chemical reasons why daffodils and other flowers don’t mix!

Daffodils, it seems, are the cold killers of the cut flower world. Placed in a vase with other flowers, they can cause premature wilting and death. Why is this, and is it seen with all other flowers, or are there exceptions? Researchers have tried to tackle these questions and come up with some surprising answers.
The first surprise is that there isn’t one sole reason, but two. Both stem from mucilage, a thick, gooey substance secreted from daffodil stems when they are cut and placed in water. Compounds in the mucilage are to blame for the effect daffodils have on other flowers.
All parts of daffodils are poisonous. We’ve previously looked at why it’s a particularly bad idea to eat daffodils or their bulbs, due to the presence of alkaloid compounds. Alkaloids are present in daffodil mucilage too, and they’re not just poisonous to humans. Studies have shown that tulips turn yellow and have reduced vase life when a daffodil is added to the vase – a consequence of the toxicity of alkaloid compounds.
Interestingly, some flowers have more tolerance for the daffodil’s alkaloid poisons than others. The vase life of irises, for example, can actually be enhanced by the addition of a daffodil. This is because a particular alkaloid, narciclasine, slows down the creation of proteins which control ageing and degradation of plants.
In other flowers, it is not the toxicity of the daffodil mucilage but its other constituents that hasten the onset of death. Sugars and polysaccharides in the mucilage promote bacterial growth in vase water. This can, in turn, lead to the blocking of water uptake through the xylem of the plant. It’s this that causes roses to rapidly wilt when daffodils are in the same vase.
So, if you’re set on having daffodils and other flowers in the same vase, is there nothing to be done? Well, not quite. Some florists suggest preparing the daffodils separately before other flowers. After leaving them in water on their own for a period of time, transfer them into clean water with other flowers without re-cutting the stems. While the other flowers in the vase might still not last as long as they would have without daffodils, they’ll still hold up for a few days.
Adding other chemicals to vase water can also combat the effects of daffodils. Studies have found that adding 8-hydroxyquinoline (HQC) or sodium hypochlorite can prevent premature wilting for some flowers. Another study found cobalt chloride could prevent stem blockage in roses, again allowing them to stay alive in the company of daffodils. Still, if you’re looking for fuss-free flower arranging, it seems it might be best to avoid daffodils in your bouquets!