Sunday, March 9, 2008

Southern magnolia

Do you have doubts about climate change? New Jersey gardeners don't. As warming winters have threatened to make New Jersey into a southern state, its gardeners have started planting southern magnolias (Magnolia grandiflora) everywhere. In the 1980s, the only southern magnolias I knew of in Plainfield were at the former Memorial Funeral Home on East Seventh Street. Now East Seventh Street has seven southern magnolias within a length of just 300 feet. 1330 East Seventh Street at the corner of Coolidge Street is southern magnolia central.

Many varieties of southern magnolia are cold-hardy in New Jersey. The best known is 'Edith Bogue', named for Miss Edith Bogue of Montclair, NJ, in whose garden it first attracted notice. My experience with 'Edith Bogue' is that it is a rapidly growing, beautiful plant that has stayed green in winters that have browned my Nellie R. Stevens hollies and blackened my aucubas.

Some southern magnolia varieties that can be purchased at area nurseries aren't as cold-hardy. A particularly beautiful and tempting one is 'Little Gem'. It is a small tree with smaller leaves than those of most southern magnolias. Unfortunately, even rather mild winters can cause serious leaf burn. An example at 828 Arlington Avenue is pictured below after the winter of 2006-2007, not a very hard winter.

The tree is in much better condition this winter, which has been very mild so far, but this 'Little Gem' would probably be happier in Virginia.

Some of the varieties of southern magnolia that thrive in New Jersey have leaves with brownish, felt-like undersides.(1) A very handsome example is at 911 Woodland Avenue.

The Woodland Avenue tree shows a feature that is common in southern magnolias, the tendency to grow in a Christmas tree shape. European gardeners often take advantage of that tendency by treating southern magnolias as topiary specimens. Most southern magnolias that I have seen in European gardens have been formally pruned to form perfect cones. An exotic look that is well suited to an exotic plant; in Europe, southern magnolias are imports. I rarely see formally pruned southern magnolias in the United States, where the species is native. That sort of formal pruning is extremely high-maintenance gardening, by the way. It's very different from pruning a yew into a cone. Yews, with tiny leaves, can be shaped with shears. One can't prune southern magnolias with shears because their leaves are too large; the leaf fragments would be grotesque. Each stem must be cut individually with hand clippers.

Southern magnolias are capable of reaching great size in our climate. The grandest southern magnolia I have seen in the vicinity is at 221 East Westfield Avenue in Roselle Park. Twenty-five years ago, before the lower branches were removed, the house behind the tree was essentially invisible.

Magnolias are primitive trees. How primitive? Magnolias evolved more than 50 million years ago, before pollinators like bees and butterflies existed. Beetles are their pollinators.(2) The huge, white, lemon-scented blooms of southern magnolias might be the epitome of romance, but their intended audience is beetles, not you.
A close relative of southern magnolia, but even more fragrant, is sweetbay magnolia (Magnolia virginiana). I have some sweetbay magnolias in my garden, but I would be grateful to hear of any examples of this species that can be seen from the street.

(1) There is apparently some correlation between brown leaf undersides and cold-hardiness (Manual of Woody Landscape Plants, Michael Dirr. Stipes Publishing Company 1998, p. 598). That correlation doesn't work for 'Little Gem', however.

(2) Magnolias, J.M. Gardiner. Globe Pequot Press 1989, p. 14.

Copyright Gregory Palermo

1 comment:

Millie said...

I love southern magnolias!! this is soo cool!!! thanks!
Can i follow you? i didnt see a follow this blog thing!