Growing Concerns 472: Consider trees drawbacks, Native plant sources

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Consider Tree's Drawbacks as Well as Attributes When Deciding What to Plant

My family will be moving this summer to a house on a two acre lot. There are already plenty of birch, a few small oaks and many pines growing in the wet, sandy soil. The house is newly constructed on what was long ago a farm, so I think the current trees showed up naturally, as opposed to having been planted as part of someone's landscape plan.

I would like to plant some shade trees and evergreen trees. After visiting the nursery I'm considering variegated Norway maple, honeylocust and ginkgo. Do you have any thoughts about the appropriateness of these choices?

Also, if you could offer some guidance about types of evergreen trees that are not slow growing?

- K.M. -

Dear K.M.,

Two acres can be your own private park, an opportunity to enjoy nature. Wouldn't you like to plant trees that will not only provide shade but attract a diversity of birds, butterflies and other wildlife?

One way to do that is to plant native species that might occur naturally on a site with birches and oaks. Red maple (Acer rubrum) and American hornbeam (Carpinus caroliniana) are two.

The three trees you mention are not natives, although they are fine trees. And like all plants, each has some bad aspects that should be considered along with the good. Since you write "After visiting the nursery," I suspect you based your decisions solely on the good points -- handsome foliage, vigor and other attributes highlighted in a sales area. I won't repeat what you already know, then, but comment on a few "dark side" characteristics to help you make a balanced decision.

The Norway maple (Acer platanoides) doesn't know how to "play nice" outside its native land. Here, its seedlings grow thick and fast, in both woodlands and fields, blocking so much light over such a long growing season that natives at their feet are shaded out. In many places, habitats once full of diverse flora and fauna have become boring Norway maple thickets.

The variegated form of this tree is not entirely stable but reverts readily, producing limbs with all-green foliage. Because a green leaf has more chlorophyll than its two-tone counterpart, reverted portions grow faster and eventually take over. So an annual check-up and pruning is a must.

Honeylocusts (Gleditsia triacanthos) bear the curse of most fast-growing trees -- a great many insects call these trees "home." Many people who would love to picnic in the shade of their honeylocust sit at umbrella tables instead to avoid the insect fall-out and the drip of honeydew-- insect excrement -- that makes surfaces beneath the tree sticky or black with sooty mold.

Of your three choices, ginkgo (Ginkgo biloba) is my favorite, but also has flaws. One, its fall color usually lasts just one or a few days. Two, unless you buy a named male variety such as Autumn Gold, there's a 50-50 chance it will eventually bear an annual crop of unpleasantly scented fruit.

Fast evergreens for moist sandy soil include white pine (Pinus strobus) and eastern arborvitae (Thuja occidentalis). The relationship you'll have with them will be as long as with your shade trees so look both ways. Surf the Internet -- enter the tree's scientific name in a search engine -- or check a book such as "Manual of Woody Landscape Plants" by Michael Dirr to learn about them before you let them charm you at a nursery.


 Where to buy Michigan grown plants

I attended your native plant seminars and decided to plant more of the native trees and shrubs. Is it okay to buy them by mail, from out of State? Or where can I buy Michigan-grown plants?

- A.S. -


A species can be native to a huge area. Red maple, for instance, is native from northern Canada to the Deep South. Such a species may be suited to a general set of environmental conditions but has many genotypes -- populations adapted to a locality within that big region. So a plant is a good bet as long as it's the right species but the ideal may sometimes be a Michigan genotype.

Growers in the Michigan Native Plant Producers Association offer local genotypes -- plants grown from seed collected in Michigan natural areas. For trees and shrubs, check Wildtype Nursery in Mason (517-244-1140; open Sundays from 11 to 4), Wetlands Nursery in Saginaw (989-752-3492; open Thursday and Friday from 3 to 6) and The Native Plant Nursery in Ann Arbor (734-677-3260; at the Ann Arbor Farmers Market Wednesday and Saturday mornings).



Short report


Time to make new shrubs for free.

Take four- to six inch cuttings from bushes such as lilac, rose, boxwood and spirea. Cuttings should be taken from tips while the new wood is still green but has become firm -- a twig will snap when bent. Pull off all but the top one or two leaves and then firmly insert the cut end into moist sand. Cover this "stuck" cutting with a clear glass jar or plastic jug so that it will stay moist during the month or year it will take to strike its own roots.



Green thumbs up

to realists who say "I've battled this same weed in this same groundcover, or that pest on that plant, every year. Perhaps I should reevaluate my choice in plants, or accept the situation as it is!" From resignation can sometimes come great revelation.


Green thumbs down

to making snide criticisms while on a garden tour. The host gardeners open their gates to hundreds of strangers to help raise money for projects like relandscaping parks or schools. I find inspiration in every one. If you seek perfection, stay home in front of the TV.


orginally published 7-13-2002