University of Vermont Extension 
Department of Plant and Soil Science

Anytime News Article

Dr. Leonard Perry, Extension Professor
University of Vermont
Test your knowledge of trees, and perhaps learn some good choices and proper practices, with the following 10 questions.  These and many more questions on all aspects of gardening, along with in-depth answers, can be found in the recent book by University of Vermont professor emeritus Dr. Norman Pellett, Gardener's Quiz Book.
Which of the following are native to the northeastern United States and southeastern Canada: Norway spruce, boxelder, balsam fir, green ash, eastern white pine, hophornbeam, littleleaf linden?  The answer is all except the Norway spruce and the linden.  The former may seem obvious, even though this European native has been widely planted here.  The oldest known remains of the Norway spruce, found in Sweden in 2008, date back 9500 years.  This linden is another European native, found extensively along streets in many cities here.
Which trees of the following are most tolerant of wet soils: sugar maple, Colorado spruce, weeping willow, and eastern larch?  The willow and larch "tolerate" wet soils, but won't tolerate those that stay wet continually.  An ideal site is along a pond, a wetland area, or one that may puddle during a heavy rain but then drain.
What is a "deciduous" tree?  This is one that loses it leaves each fall with the onset of shorter days and cooler temperatures.  These conditions result in the chemical breakdown of a layer of cells (called an "abcission" layer) at the base of the leaf-stem (called "petiole"), causing the leaves to fall off.

Some shrubs, and more often trees, are found in nurseries with a ball of soil wrapped in  burlap around the roots.  These are called "balled and burlapped" or for short "B and B". What is the proper planting depth for a B and B tree or shrub?  Plant these with the top of the root ball level with the soil surface.  This is very important, and a main reason for eventual loss of new plantings when planted too deeply.  Dig the hole only as deep as the height of  the root ball.
Can you think of the name of a tree with the name of a domestic animal?  How about of a flavor?  A country?  A state?  A color?  Dogwood and pussy willow are a couple choices for the animal name.  For a flavor, sourwood is an example.  For a country, you've seen Norway spruce above, but Chinese chestnut works too.  Ohio buckeye and Colorado spruce are a couple with state names.  Several trees have "colorful" names including blackgum, yellow birch, and yellowwood.
I love the word jumbles in the book by Dr. Pellett.  Can you figure the name of the tree, rearranging the letters "hibrc" and "ocrhyki"?  The first you just saw above--birch-- and the other is hickory.
When does most root growth occur in native trees and shrubs in the United States and Canada, and why is this important?  Most root growth is in late spring to early summer, then again in fall.  These are the best times to plant, as roots are growing and will establish most quickly then.  Non-native plants from more southerly regions may have most root growth in summer, yet planting at the same times is best as it avoids the drying summer heat.
Of the following, which are most tolerant of deicing salt so best near roads that are heavily salted: sugar maple, black locust, Canadian hemlock, eastern white pine, and honeylocust?   Black locust and honeylocust are quite resistant.  Many evergreens may be injured by "flying salt" sprayed from plows and cars as they drive by.

If you were to cut off the following 10-year old trees at the ground level, which would usually grow new stems and survive: pine, willow, maple, tuliptree, or spruce?  The willow, maple, and tuliptree are correct.  In fact, if they're healthy, most deciduous woody plants will regrow after their stems or trunks are damaged.  While evergreens generally don't regrow, some members of the cedar family such as falsecypress may regrow but slowly and uneven.
Some trees start dripping sap, often called "bleeding", when pruned in the spring.  Is this a problem, and how can it be avoided?  Some trees such as maples, birches, hophornbeam, musclewood, walnut, butternut, and yellowwood bleed in early spring if injured or pruned.  The pressure of the sap rising in the trunk and stems causes it to escape such wounds.  This is basically the principle of tapping maples in spring for their sugary sap.  Since the sap contains sugars the plant needs, as well as water, heavy pruning can be detrimental.  A limited amount of pruning is probably of more concern to the gardeners than to the tree.
Look for the Gardener's Quiz Book in bookstores, online, or from the Vermont Master Gardener program (

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