One of the more unique olfactory pleasures of planet Earth is the rich, deep, vanilla-like aroma produced by the ponderosa pine (Pinus ponderosa¹) on hot summer days. Also known as western yellow pine, silver pine, bull pine, rock pine, pitch pine and blackjack pine, P. ponderosa is the tallest pine in the world.

Simply follow these instructions:

1. Travel to a part of the world where you are likely to find a ponderosa pine in its native range.

Ponderosa pine are native to the western interior of North America, and can particularly be seen in north-eastern Washington and Oregon, northern Idaho, Utah and California, and southern British Columbia in Canada. If you are further south, you might try central or northern Arizona or New Mexico, especially the highlands around Flagstaff. The ponderosa pine may also be found in northern Mexico at higher elevations.

If travelling by car, a number of highways offer outstanding opportunities to smell ponderosa pine. Among these are the Crowsnest Highway (Highway 3) in British Columbia, particularly between Princeton and Rock Creek, and again from Creston through Fernie. Also, do try Highway 2 in the extreme north-west of Montana (near Libby), and the Bryce Canyon National Park.

For those not travelling by car, ponderosa pine may also be found in several areas more friendly to foot or bike travellers. For example, the main campus of the University of Montana (in Missoula), features extensive ornamental plantings of the ponderosa pine, which, not coincidentally, is also Montana's official state tree.

2. Learn how to recognise a ponderosa pine.

Look for a solitary conifer with long, slim, yellow needles in bunches of three, but the real give-away is the deeply red-coloured bark. Some describe this colour as 'cinnamon', as it can be quite rich and vivid. On older trees, the bark may also have pronounced dark vertical grooves along it, similar in orientation to those found on the Douglas-fir. Several images are, of course, available online.

The cones² are large, cute and pineapple-like.

3. Wait for a very hot summer day in July or August.

Check the thermometer. Best results occur at temperatures above 30-35°C (about 95-100°F). Ensure that the sun is out, and that it is not overcast. Be aware, this is serious heat so take along plenty of portable fluid.

4. Set out to find a mature ponderosa pine.

Refer to step 2, above, for a description of the ponderosa pine, and bear this in mind. For best results whether driving or walking, try to find a trail that is at a high elevation, and away from the city air (if this is a local problem).

Ponderosa pines tend to be solitary trees, and under natural conditions have little or no understorey³, forming what many have termed a 'park-like' setting. This arises from the fact that the ponderosa pine is a 'fire-dependent' species, in that it relies on frequent (5-10 years) low-intensity groundfires to kill off potential competitors and retain its dominance. Thus, no understorey. Ensure that this is a mature ponderosa pine, eg more than 60cm (2ft) in circumference.

5. Approach the ponderosa pine and insert your nose into one of the deeper grooves in the bark for best results.
6. Inhale deeply. The vanilla-like aroma you smell is an extremely pleasant side-effect of the tree's resistance to fire, thanks in part to its thick bark and deep roots.

Written in 2003 by former Researcher U240281 Mew Gull