Silver vases and cut flowers

Keep the vessel and the treatment separate

A beautiful silver vase can be part of enjoying flowers. Whether its metal extends their life is a different question. The studies discussed here do not establish a reliable benefit from putting flowers in sterling silver or dropping a silver coin into the water.

Professional postharvest treatments use defined chemicals and conditions. The metal content of a vessel does not tell you the concentration or chemical form reaching the flower.

• Start with the cut-flower Silver Fact

What the carnation experiment measured

Veen and van de Geijn’s 1978 radiotracer study compared silver supplied as nitrate with a silver-thiosulfate complex in cut carnations. In that experiment, silver from the nitrate treatment moved about 3 cm per day; the thiosulfate complex moved about 2 m per hour and retained its anti-ethylene effect.

Those figures describe the tested flower and treatment conditions. They are not universal speeds for every stem and do not measure what comes out of a silver vase.

Sources: Veen and van de Geijn, Planta.

Ethylene sensitivity matters

Ethylene is involved in the aging responses of some cut flowers. UC Davis identifies carnations as ethylene-sensitive and discusses professional pretreatments. Responses vary, including among carnation cultivars and between flowers at different stages.

Research in Arabidopsis identifies a predominant role for the ETR1 receptor in silver’s inhibition of ethylene responses. It adds a molecular explanation, but is not a trial of domestic bouquets in metal vessels.

Sources: UC Davis Postharvest Research and Extension Center; McDaniel and Binder, Journal of Biological Chemistry.

A practical approach for a collector

• Ask the florist for care instructions for the particular flowers and any supplied preservative.
• Protect the silver object’s finish and construction. A separately supported liner may be appropriate, but it must not stress or trap moisture against a fragile piece.
• Do not assume a weighted vase can be submerged during cleanup just because it holds water at the top.
• Do not prepare silver-thiosulfate mixtures or use colloidal-silver supplements as flower food. Follow product labels and local disposal requirements for commercial treatment solutions.

• Check the base before washing
• Keep antimicrobial and health claims separate
• Return to Silver and Water

What remains unproven

No universal release rate for silver ions from sterling vases is asserted here. Alloy, surface area, coatings, water chemistry and contact time can differ. A nanoparticle experiment cannot supply a missing measurement for a bulk-metal vessel.

The useful conclusion is narrow: evidence for a defined horticultural treatment does not, by itself, support the same claim for a decorative object.

Sources: Xiu and colleagues, Nano Letters; Veen and van de Geijn, Planta.