Green Ash, Red Ash
Fairly fast-growing trees, most of which tolerate hot summers, cold winters, and many kinds of soil, including alkaline sorts. Chiefly used as street, shade, lawn, and patio shelter trees. In most cases, leaves are divided into leaflets. Male and female flowers (generally inconspicuous, in clusters) grow on separate trees in some species, on the same tree in others. In the latter case, flowers are often followed by clusters of single-seeded, winged fruit, often in such abundance that they can be a litter problem. When flowers are on separate trees, you’ll get fruit on a female tree only if a male tree grows nearby.
Ash trees are prone to borers. In some parts of California, ash whitefly is a problem; these chalky white, 1/8-in.-long insects colonize in patches on leaf undersides. Outbreaks are usually controlled by natural enemies; avoid spraying with broad-spectrum insecticides, which are likely to wipe out these beneficial predators.Fraxinus pennsylvanica
Native to the eastern U.S. This deciduous tree grows to 30–40 ft. tall and wide, with a compact, oval crown. Gray-brown bark; dense, twiggy structure. Leaves are 10–12 in. long, divided into five to nine bright green, rather narrow, 4–6-in.-long leaflets. Male and female flowers on separate trees. Takes wet soil and severe cold, but foliage burns in hot, dry winds.
Seedless varieties include ‘Patmore’, with a handsome form and good resistance to pests and diseases.
Native to the eastern U.S. This deciduous tree grows to 30–40 ft. tall and wide, with a compact,...
This deciduous shrub is native to eastern North America. Unlike most hollies, it will thrive in boggy ...
Native to western Canada and mountainous parts of western U.S. To 15–20 ft. tall, spreading by r...