Which plant listed is the tallest among shrubs at approximately 8 feet?

• A. Thunberg Spirea
• B. Japanese Adromeda
• C. Slender Deutzia
• D. Shrub Althea

Answer: (D)

The main idea here is recognizing typical mature heights of common landscape shrubs. Shrub Althea (Hibiscus syriacus) is a large deciduous shrub that commonly reaches about 8 to 12 feet tall in garden settings, sometimes even taller with ideal conditions. The other options stay noticeably shorter: Thunberg spirea is usually around 3 to 4 feet, Slender Deutzia tends to 4 to 6 feet, and Japanese Adromeda (Pieris japonica) generally tops out around 6 to 8 feet but often remains slightly shorter or more compact depending on cultivar and pruning. Because Shrub Althea reliably grows near 8 feet or more, it best matches the description of the tallest shrub among the list.