CLA Plant Materials & Horticulture Flashcards

What is the primary purpose of specifying native plants in a US landscape design?

Answer: Reduce irrigation need and support local wildlife

Native plants are adapted to local climate and soil, requiring less supplemental water and providing habitat for native insects and wildlife.

A landscape architect specifies Phragmites australis for a wetland restoration. Why might this be a problem?

Answer: It is an invasive species that outcompetes native wetland plants

Common reed (Phragmites australis) is an aggressive invasive in US wetlands that forms dense monocultures and reduces biodiversity.

Which fertilizer designation indicates the percentage of nitrogen, phosphorus (P₂O₅), and potassium (K₂O) respectively?

Answer: N-P-K

The standard fertilizer grade reads N-P-K (nitrogen–phosphorus–potassium), always in that order on the bag label.

What is the recommended planting depth for most trees to avoid crown rot?

Answer: Root flare at or slightly above grade

Trees should be planted so the root flare is at or just above finished grade to prevent stem and root rot from excess soil moisture.

Which of the following grass species is a cool-season turf commonly seeded in the upper Midwest and Northeast US?

Answer: Kentucky bluegrass

Kentucky bluegrass (Poa pratensis) is a cool-season turfgrass that thrives in the northern US with cold winters and mild summers.

What does 'dioecious' mean when used to describe a plant species?

Answer: Having male and female flowers on separate plants

Dioecious species like hollies have male and female reproductive structures on separate individual plants, requiring both sexes for fruiting.