Rhododendrons

CURATOR: Paul Wieczoreck

The collection, located along the southern boundary of the Farm, was started in the 1960’s by Harrison Flint who propagated seed purchased from a woody plant supplier and planted numerous seedlings. The original objective was to evaluate these plants for hardiness and suitability for landscape use in Vermont. Dr. Norman Pellett later added many additional species. These plants today represent a test of time—most are more than 35 years old and are some of the largest specimens growing in northern Vermont. They represent a part of our historical past and are much like what would have been found on the great estates of the early 20th century. This collection consists of mature hybrids, sometimes referred to as ironclads. Accompanying these hybrids is a group of species and unnamed hybrids grown from seed from the Schumacher Seed Company of Cape Cod.

Rhododendrons can be found throughout the world. Just under 20 species are native to North America, with the vast majority of these being deciduous azaleas. We have 15 species of rhododendrons growing at the Farm. It can be said that we live at the end of the rhododendron world. Three of the four species native to Vermont are small disjunct colonies at their northernmost range.

For rhododendrons to thrive in the wild or in the garden, two main conditions must be met—suitable location and soil condition. Rhododendrons don’t like temperature extremes of cold or heat. In the wild they’re found in mountainous terrain growing in the shadows of overstory trees. The right location needs to be cool and wet, with specific soil pH levels. The soil also needs to be well drained and very high in organic matter. In growing these plants, attempts should be made to have organic matter as high as 50 percent (to give this some perspective, an average cornfield will have organic matter of 3 to 5 percent, and a good garden soil will be 8 to 10 percent).

This collection of rhododendrons at the Hort Farm offers to students and the public a view of plants that are mature and successfully grown in a harsh environment. This is certainly a collection of merit that displays a color in bloom that is not outdone anywhere in northern Vermont.