Notwithstanding an unexpected plunge into freezing temperatures, most spring-flowering plants in the Botanical Garden will be three weeks to a month early this year. Without a doubt, the most impressive of these early bloomers will be our magnolias. Normally opening in late March and April, the Asiatic deciduous magnolia already started showing their finery in the last week of February. Magnolias in this group produce flowers on naked stems, well before leaf emergence. This group is particularly well represented in the David C. Lam Asian Garden and plants in bloom—many of which are large trees, 10 m tall or more—typically elicit much picture taking. Among the first to bloom is Magnolia campbellii, a magnificent, but somewhat frost-tender deciduous species, native to the Himalayas, western China and parts of Indochina, where it grows to 50 metres tall. The huge furry flower buds open to produce giant, water-lily-like flowers with tepals of white, pink or magenta. The flowers of M. campbellii are the most symmetrical of all of the large deciduous Asiatic magnolias. Magnolia sprengeri, a hardier species from central China is similar, but has flowers that are somewhat less symmetrical and that smell of chewing gum. Magnolia sargentianais considered one of the most magnificent of all temperate trees, growing to 25 m or more with a spreading, rounded crown. It is much valued for its huge, fragrant flowers and broad, sturdy leaves. The prominent grey-fuzzy buds of Sargent’s magnolia open slowly to reveal individual violet centred blooms with paddle-like, rosy pink-and-white tepals that gradually adopt a drooping, rag-doll like posture. Flowers remain open and attractive for up to three weeks, given cool temperatures. Magnolia dawsoniana is a related species with similar, but slightly smaller flowers.
Throughout the Garden, both wild deciduous and evergreen species as well as cultivated selections of magnolias are prominently displayed. In the Asian Garden, magnolias stand out against a background matrix of native conifers, shrubs and ground covers, maples and rhododendrons, while in the Carolinian Forest Garden, eastern North American native magnolias vie for space with a diverse mixture of deciduous hardwood species. These species typically open their flowers in late spring well after leaf emergence. The majority of the world’s two hundred or so magnolias hail from the subtropical mountain forests of Southeast Asia and Central and South America, while temperate magnolias are found in eastern North America and especially east Asia, from the Himalayas through China to Japan. Of the temperate sorts, the Botanical Garden counts about forty-five species, the majority from Asia. There are also about twenty early summer-flowering evergreen species from China and Vietnam, most of them little known in cultivation, but all of them worth coming to see in the Botanical Garden.
Submitted by Douglas Justice, Associate Director, Horticulture and Collections, Feb 28, 2015.