A university study found that smaller trees recover more rapidly after transplanting, and a skinny "whip" planted at the same time as a 3-inch caliper tree can catch up in size within a few years. But some gardeners want the larger size right off the bat. The #1 caution I can give you on planting your trees is be careful not to plant them too deeply. Find the basal flare--the spot where the trunk widens and the top roots emerge. That spot should go at or slightly above ground level. The best times to plant trees are spring and fall, because the tree can focus energy on establishing roots without the pressure of the summertime heat. Finally, I've never encountered a Bradford Pear that smells strange. They do have fragrant blossoms, and that essence goes away with the blooms.