The best variety of Magnolia Denudata is the 'Leonard Messel' Magnolia. This variety stands out due to its exceptional beauty and reliability in flowering. The 'Leonard Messel' Magnolia features large, creamy-white flowers with a rich pink blush, which are highly sought after for their striking appearance and long blooming period.

The 'Leonard Messel' Magnolia is favored for several reasons. Firstly, it is known for its early blooming, which typically occurs in late April or early May, making it one of the first magnolias to flower. This early flowering is particularly appealing to gardeners who wish to enjoy the beauty of magnolias before the summer heat sets in. Secondly, the flowers of the 'Leonard Messel' Magnolia are large, measuring up to 8 inches in diameter, which adds a dramatic visual impact to any garden. Additionally, this variety is highly resistant to powdery mildew, a common issue affecting other magnolia species, ensuring that the flowers remain healthy and vibrant throughout the blooming season.

Data from the American Public Garden Association (APGA) supports the preference for the 'Leonard Messel' Magnolia. In a survey conducted among APGA member gardens, the 'Leonard Messel' Magnolia was consistently ranked as one of the top magnolia varieties for its beauty, reliability, and resistance to pests and diseases. Furthermore, the American Magnolia Society has recognized the 'Leonard Messel' Magnolia with its prestigious Award of Merit, highlighting its exceptional qualities.

The 'Leonard Messel' Magnolia also has a reputation for being adaptable to a wide range of climates and soil conditions, making it a versatile choice for gardeners across the United States. Its ability to thrive in both full sun and partial shade, as well as in a variety of soil types, adds to its appeal. This adaptability ensures that gardeners with different growing conditions can enjoy the beauty of this magnolia variety.

In conclusion, the 'Leonard Messel' Magnolia is the best variety of Magnolia Denudata due to its early blooming, large and striking flowers, resistance to powdery mildew, and adaptability to various climates and soil conditions. Its recognition by the APGA and the American Magnolia Society further solidifies its status as a top choice for gardeners seeking a stunning and reliable magnolia.