Once highly prized shade trees, elms have fallen on hard times. Dutch elm disease (spread by a bark beetle) has killed millions of American elms in North America and can attack most other elm species. Many of the larger elms are appealing fare for various types of aphids, beetles, leafhoppers, and scale, making them time-consuming to care for, messy, or both. Elms have other problems not related to pests. They have aggressive, shallow root systems, so you’ll have trouble growing other plants beneath them. Many produce suckers; branch crotches are often narrow, splitting easily in storms. Still, elms are widely planted, and researchers continue to devote much effort to finding disease-resistant varieties. Elms tolerate a wide range of soils. Poor yellow fall color except as noted.Ulmus pumila
Deciduous, native to Russia and northern China. Grows to 50 ft. tall and 40 ft. wide. Smooth dark green leaves are 3/4–2 in. long. Resists Dutch elm disease and endures cold, heat, aridity, and poor soil—but has brittle wood and weak crotches and is not a desirable tree. Possibly useful in holding soil against erosion; fast growth also makes it suitable for a windbreak or shelter belt. Papery, winged seeds disperse seedlings over a wide area.
Warm-season vegetable from tropical Asia. Large, erect, bushy plant to 6 ft. tall, with big, bold, dee...
Mediterranean native to 2 ft. tall and 1 1/2 ft. wide. First growth produces a clump of bright green, ...
Two kinds of mustard are popular in American gardens, both derived from plants native to the Mediterra...