Pine trees, junipers, the mighty redwood are all members of an ancient family, the conifers.
Conifers have been around for 300 million years. They were the dominant plant of the Mesozoic Period, or the Age of Reptiles, and a primary food of many herbivorous dinosaurs.
Adding conifers to a landscape is an excellent way to create year round color. They make excellent anchor plants and they often create food and habitat for wildlife, increasing your garden’s biodiversity.
All conifers are perennial woody plants that get thicker and larger with age. The secondary growth that allows a giant redwood to attain its amazing size all takes place in the cambium layer, just under the bark. Conifers (Pinophyta) are unlike many of our common garden plants, and for several reasons. The most obvious difference is that conifers are gymnosperms, which are cone-bearing seed plants.
Botanically, a cone is called a strobilus. Strobili protect the seeds as they develop. This can take from four months to three years, depending on the species and environmental conditions. Some species of conifer need fire to release their seeds. These cones, in particular, will stay tightly closed for 60 to 80 years, waiting for fire.
Cones can range in size from 1/10 of an inch to two feet in length. There are male cones that produce pollen, and female cones, where pollination occurs. Both types of cones are usually found on each tree. Different species of conifer spread their reproductive cycle out over one, two, or three years.
While some plant families include thousands of species, the conifers boast only 7 or 8 subfamilies (depending on which botanist you ask) and most of us recognize even fewer. There are less than 630 living species of conifer worldwide. These include pine, cedar, redwood, larch, cypress, fir, Douglas-fir, kauri, juniper, hemlock, yew, and spruce. All conifers are in the Pinales order and the Pinaceae family. Botanists break down the subfamilies in this way:
Abietoideae - fir
Cedrus - cedars
Cupressaceae - cypress
Larix - larch
Pseudotsuga - Douglas-fir
Tsuga - hemlock [Not to be confused with poison hemlock]
Piniodeae - pine
Piceoideae - spruce
Taxaceae - yew
Other subfamilies include Araucariaceae and Podocarpaceae, both found in the southern hemisphere, Sciadopityaceae, found in Japan, and Cephalotaxaceae, mostly found in SE Asia.