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ISA Certified Arborist — Practice Exam

Installation and establishment: practice questions

Our ISA Certified Arborist bank has 27 questions on this topic. Here are 5 of them with answers; the full mock exam draws from every topic, like the real one.

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Question 1

When buying a balled-and-burlapped tree, how large should the root ball be?

  1. At least 3 feet across, whatever the trunk size, measured at the widest point
  2. At least 10–12 times the trunk diameter measured 6 inches above the flare
  3. The same width as the crown spread
  4. Twice the trunk diameter
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B. At least 10–12 times the trunk diameter measured 6 inches above the flare — The top of the root ball should also be flat, not rounded.

Question 2

How should a tree be lifted into the planting hole?

  1. By the root ball, not the trunk
  2. By the burlap ties around the trunk
  3. By the lowest scaffold branch
  4. By the trunk, just above the flare
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A. By the root ball, not the trunk — Lifting by the trunk can tear roots away from the ball.

Question 3

According to the USDA Forest Service Tree Owner's Manual, how far from buildings should a new tree be planted?

  1. At least 50 feet
  2. At least 5 feet
  3. At least 15 feet
  4. At least 3 feet
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C. At least 15 feet — Also keep at least 3 feet from pavement and 15 feet from other trees.

Question 4

During the first three years after planting, how much water should a tree get when the soil is dry?

  1. About 1 cup of water per inch of trunk diameter
  2. About 50 gallons a day, regardless of the tree's size
  3. About 1½ gallons per inch of trunk diameter
  4. Only what rain provides, since roots must learn to search
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C. About 1½ gallons per inch of trunk diameter — Check soil moisture about 6 inches deep; fast-draining soils need checking more often.

Question 5

How wide and deep should a planting hole be?

  1. 2–3 times wider than the root ball, but only as deep as the root ball
  2. Twice as deep as the root ball, with amended backfill placed below it for drainage
  3. As wide as the root ball and twice as deep
  4. Exactly the size of the root ball in both directions
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A. 2–3 times wider than the root ball, but only as deep as the root ball — A shallow, broad hole keeps the tree from settling too low.

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