Naturally, the term "hardwood" refers to trees and shrubs that have dense, hard wood, but --- more accurately --- they are mainly flowering deciduous trees that have well-developed water transport systems and tightly packed fibrous cells. Hardwoods are used prevalently as building material and are of significant economic importance for their use in constructing furniture. In addition, many species display dramatic autumn foliage, provide habitat for wildlife and make attractive landscaping plants. Whatever your purpose for growing hardwoods, several species have fast growth rates and are easy to care for.
Silver maple (Acer saccharinum) is a medium to large tree that can reach heights of 24 to 30 m (80 to 100 feet) tall. Silver maple is one of the most common hardwood trees found in the eastern United States, but it is not native to the UK. It is a hardy tree that grows well even in poor conditions. Silver maples produce a dense and aggressive root system that fuels its rapid growth. Healthy trees are prolific seed producers and seedlings often develop in the vicinity of the parent tree. The vigorous growth of the silver maple creates an unkempt and awkward limb structure, with new shoots emerging from the root system most of the growing season. Pruning is required to maintain a well-shaped tree. The shallow root system of silver maples can cause structural damage to pavements, sewage systems and other nearby structures, so give careful consideration to where you plant them.
Black walnut (Juglans nigra) is a large hardwood tree that can reach a mature height over 30 m (100 feet). Black walnut is a valuable tree both for its fine, strait-grained wood, which is very valuable, as well as for its edible walnuts and habitat for wildlife. Wood from black walnut is commonly used to create veneer surfaces for furniture. Healthy walnut trees can live over 200 years. Part of their biological success is due to the chemical juglone, which they produce in the roots, leaves, trunk and nut husks. This chemical inhibits the growth of many other species of plants and trees in the vicinity.
The empres tree (Paulownia tomentosa) is native to China, though it was named for a Russian empress. The empress tree is a medium sized hardwood that reaches an average height of 15 m (50 feet), but has a very fast growth rate. Empress trees are successful landscaping trees, as they are hardy, require little attention and produce numerous large purple flowers in the spring. They have also become an economically viable timber crop since the wood is popular for Oriental furniture. Because the empress tree has become an invasive species in some areas where it has been planted, give careful consideration and care when planting them to prevent ecological damage.