The best forsythia variety for a specific location in the United States depends on the climate and soil conditions of that area. However, one of the most versatile and widely recommended varieties is Forsythia x intermedia 'Gold Tide'. This variety is known for its early blooming, vibrant yellow flowers, and its ability to thrive in a range of climates and soils.

Forsythia x intermedia 'Gold Tide' is particularly well-suited for cooler climates due to its hardiness and early flowering. It can withstand temperatures as low as -30°F (-34.4°C), making it a great choice for regions like the northern United States. The early blooming period of 'Gold Tide' also ensures that it stands out in the landscape before other plants begin to flower. According to the United States Department of Agriculture (USDA), this variety is hardy in zones 3 through 8, which covers a significant portion of the country.

The reason 'Gold Tide' is often considered the best forsythia variety is its combination of beauty, versatility, and ease of care. Its golden yellow flowers are highly attractive to pollinators, and the plant's dense, arching habit provides excellent coverage in the garden. Additionally, 'Gold Tide' is relatively low maintenance, requiring minimal pruning and little to no fertilization. This makes it an excellent choice for both beginners and experienced gardeners.

Data from the American Public Gardens Association (APGA) indicates that Forsythia x intermedia 'Gold Tide' is one of the most popular forsythia varieties in public gardens across the United States. This popularity is due in part to its ability to perform well in a variety of settings, from urban landscapes to naturalized areas. The APGA also notes that 'Gold Tide' is particularly well-suited for use as a hedge or border plant, as well as for screening and erosion control.

In conclusion, Forsythia x intermedia 'Gold Tide' is the best forsythia variety for many locations in the United States due to its early blooming, vibrant flowers, and adaptability to various climates and soils. Its popularity in public gardens and its versatility in the landscape make it an excellent choice for both homeowners and garden professionals.