CLA CLA Plant Materials & Horticulture

Question 1

Which USDA Plant Hardiness Zone covers most of the US Gulf Coast, including southern Louisiana and Mississippi?

Accepted Answer

Zone 9a

Answer

Zone 9a (average minimum −6.7°C / 20°F) covers much of the Gulf Coast where mild winters allow subtropical plants to thrive.

Question 2

What is the botanical name for Eastern Redbud, a commonly specified native flowering tree in the eastern US?

Accepted Answer

Cercis canadensis

Answer

Cercis canadensis is Eastern Redbud, known for its magenta spring flowers directly on bare branches before leaf-out.

Question 3

A plant specification calls for '3" Cal.' What does 'Cal.' indicate on a plant schedule?

Accepted Answer

Caliper (trunk diameter) measured 6 inches above grade

Answer

Caliper refers to the trunk diameter of nursery trees, measured 6 inches above the ground for trees up to 4-inch caliper.

Question 4

Which soil pH range is generally considered optimal for most landscape plants?

Accepted Answer

5.5–6.5

Answer

Most landscape plants grow best at pH 5.5–6.5 where nutrient availability is highest and soil biology is most active.

Question 5

What does the term 'B&B' mean when specifying trees on a planting plan?

Accepted Answer

Balled and burlapped

Answer

Balled and burlapped (B&B) trees are field-grown with a soil root ball wrapped in natural burlap for transplanting.

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