It's Christmas tree season. Here's some facts for the safety of those real trees.

2000 Fire Publications - Scotch Pine Christmas Tree Fire Tests. Report of Test. FR 4010.

Of particular note is the 8th tree that was fresh cut and kept in sufficient water for the 3 weeks of the study..
A single match was insufficient to produce ignition of the eighth tree. Ignition was attempted a second time using an electric match composed of an entire matchbook containing 20 paper matches (Figure 2). This second attempt also failed to produce ignition. Finally, an open flame was applied to the tree using a propane torch. The branches ignited briefly, but they selfextinguished upon removal of the torch from the branches.
You can use the study to show why to take care of the tree, as well as how much of a hazard they can be if not taken care of. An idea - not a new one, but we tend to assume people are smarter than they act, and don't need to be reminded of the hazard - to do is to try and dry out a tree and invite the local TV news people to come do a story on tree safety while you burn it in either the burn similator or somewhere else to show the often tragic effect.