I thought this might be an interesting thread to start. I'd like to hear from others, "what wood I would never burn in my stove". Maybe it stinks, produces no heat, etc., etc. An obvious example would be any wood that has been pressure treated, as they contain deadly compounds. However, natural traits of some trees make them terrible burning candidates. Those are the ones I'd like to hear other's input on. Here is my contribution: Ginkgo biloba: Gingko Tree, Maidenhair Tree. It is unlikely that anyone would normally burn this tree, as it is not native to our country. But, it has become a very popular landscape tree and it is used heavily in street plantings in cities due to its compact form and tolerance to pollution. Due to it's popularity in landscapes, wood may occasionally become available to us cut-and-burn folks. DONT DO IT! Here is why. Ginkgo is a far relative to Poison ivy, poison sumac, and poison oak. It is actually in the Cashew family. Members of this family are called Toxicondenderons, due to the presence of Urushoil oil, a non-toxic but highly allergenic oil that results in the itchy rash commonly associated with the poisons Ivy, sumac, oak, etc. I learned, too late that Ginkgo was in this family, as our nursery has grown them for a number of years and I got "burned" by the fruit several times before realizing the cause. The fruit is about the size of a golf ball and it smells like vomit. The fruit is high in Urushoil oil, so handling it and touching anywhere on your face (especially around the eyes) will result in a poison-ivy like result (swell up like you were hit by Rocky, and itches like poison ivy). Anyway, burning Ginkgo, would volatilize the Urushoil oil, possibly exposing your lung tissues to the oils. Imagine inhaling poison sumac fumes... STAY AWAY.. Beautiful tree, but not one to burn. Side note: If you ever consider planting a Ginkgo in your yard, be sure it is a grafted male clone variety (examples "Autumn Gold", "Fastigiata", "Halka", "Princeton Sentry", "Magyar", etc.). AVOID plain seedlings, as there is a 50% chance they will be female and they will litter your yard with thousands of vomit balls in the fall. Many cities actually have ordinances restricting the planting of Ginkgos that are not male clones, because the female seeds are such a nuisance. The seeds, once cleaned, can be dried and eaten. The health food people claim it improves memory and mental health.