Eastern White Pine (Pinus Strobus)
With its 2- to 5-inch-long, soft blue-green needles, Eastern white pine has a delicate, fluffy appearance. This tree offers good needle retention, and because it has little fragrance, it reportedly causes fewer allergic reactions than heavily scented trees.
White Spruce (Picea Glauca)
Found throughout the northern United States and Canada, white spruce bears delicate, 1/2- to 1-inch-long, pale-blue needles that sometimes produce a disagreeable odor when crushed.
Bruce Spruce (Picea Pungens F. Glauca)
Blue spruce's naturally symmetrical form and dense, 1-inch-long, silvery-blue needles make it popular as a Christmas tree and as an ornamental plant. Its sharp needles may make it unsuitable for homes with young children.
Fraser Fir (Abies Fraseri)
The Fraser fir is very fragrant and retains its needles well. Native to southern Appalachia, it is symmetrically shaped with soft, 3/4-inch-long, dark-green needles with silvery undersides on sturdy branches.
White Fir (Abies Concolor)
White fir, a western U.S. native, retains its needles well and has a distinctive citruslike fragrance. It has soft, light-green to silver-blue foliage with flattened, 1 1/2- to 2 1/2-inch-long needles.