Which two plants are known to prefer more acidic soil?

Azaleas and camellias are indeed known for their preference for more acidic soil conditions. These plants thrive in environments where the pH of the soil is lower, often in the range of 4.5 to 6.0. Acidic soil helps them in nutrient absorption, particularly for elements like iron, which is crucial for their growth and flowering.

Azaleas, belonging to the Rhododendron genus, are particularly sensitive to soil pH and can exhibit iron chlorosis in alkaline conditions, leading to yellowing leaves and poor growth. Camellias benefit similarly from acidic soils, as they are native to regions that typically have these soil characteristics. Their healthy development relies heavily on maintaining the right soil conditions to support their specific nutrient uptake needs.

Looking at the other options, roses and daisies tend to prefer neutral to slightly acidic soils; lavender and sunflowers usually thrive in more alkaline and well-drained soils; and while maples and oaks can tolerate a range of soil pH levels, they do not specifically require more acidic conditions like azaleas and camellias do. Hence, the pairing of azaleas and camellias as plants that prefer more acidic soil is the most accurate choice.