The Christmas tree project: comparing the effects of five treatments on the health of cut Christmas trees (<i>Pinus radiata</i>, Pinaceae)

Our experiment tested which of five treatments kept Christmas trees (Pinus radiata) healthy for longest. The five different treatments were submerging the cut ends of pine branches in water (control), freshly boiled water (to potentially dissolve sap in cut stems), energy drink (to provide sugars), beer (to provide sugars and kill germs) or spraying the needles with hairspray (to reduce water loss). We measured how much light energy was converted to chemical energy by the needles, thus recording their health. The treatment that maintained the highest level of photosynthetic health was the hairspray, with an average of 90% of original needle health after 27 days. Branches in freshly boiled water and control treatments both retained ~68% of their original photosynthetic health. Branches in both beer and energy-drink treatments declined to about a third of their original needle health. In conclusion, we recommend spraying cut Pinus radiata Christmas trees with hairspray