Deer, Harvesters are Main Enemies of Native Orchids

WEST HARTFORD, Conn. - When people consider deer problems, they think in terms of the garden: hostas, daylilies, trilliums and roses may fall victim to the deer palette.

But Donald J. Leopold, PhD,  author of Native Plants of the Northeast, said deer are also affecting the biodiversity of northeastern forests, particularly native orchid populations. Deer enjoy the taste of lady slippers - one type of native orchid - and for a plant that takes between 10 and 15 years to flower, an entire population can be decimated in a few years.

Pink Lady's Slipper. Photo credit:
National Park Service, public domain.

"Sometimes only 10 percent of the [pink lady's slipper] population gets pollinated. So 90 percent of the flowers don't do anything," he said.

When deer eat the flowers, they will keep the plant from reproducing sexually year after year for many years, he said during a recent lecture for the Connecticut Hardy Plant Society. Leopold is a distinguished teaching professor and chair at the College of Environmental Science and Forestry in Syracuse, New York.

The deer population has reached high levels in the last 20 years, something Leopold attributed to loss of habitat and fewer hunting licenses being procured.

For the pink lady's slipper to grow, the seeds have to be connected to a fungus, and the plant remains underground for five to 10 years as a protocorm, or a stubby bunch of roots with no leaves. This is not a group of plants that takes well to harvesting (when people steal plants from the wild) or to deer, he said.

Many native orchids need specific growing conditions to thrive, and damaged plants may take many years to recover. Some never do. To protect rare orchid colonies, fencing is used to keep deer away.

Gardeners Should Only Grow Lab-Propragated Orchids 
Every native orchid in New York - no matter how common or rare they are - is protected by state law, he said. Picking orchid flowers, removing seeds or digging up the plants on state land can lead to prosecution.

"If you see these, don't go out and dig these," he emphasized.

To view native orchids in the wild, the Bruce Peninsula in Canada is the main destination for orchid pilgrimages. There are large pockets of native orchids that can be found in New York, Vermont and western Connecticut as well. Western Connecticut, especially, contains extraordinary fens, or peat lands with lots of calcium, he said. "If you see one [variety] in a certain place, there should be others," he said. In addition, "cedar swamps are some of the best places to see orchids."

Yellow Lady's Slipper Photo credit: National Park Service, public domain.

"Some people regard the showy lady's slipper as the most beautiful North American wildflower," said Leopold. The pouch on the flower can be light pink, cherry red or pure white, he said. The Eshqua Bog in Hartland, Vt., has a large collection which typically blooms in late June. "You should be able to see [these flowers]. Put it on your bucket list," he said.

It is possible to purchase lady slippers from reputable nurseries, but they usually come at a hefty price. For example, White Flower Farm offers showy lady's slippers and yellow lady's slippers for $129 each. However, if you are willing to wait a few years for the plant to flower, Spangle Creek Labs offers seedlings at more reasonable prices and Itasca Ladyslipper Farm sells mature plants propagated from Spangle Creek Lab seeds. The Vermont Ladyslipper Company, Ltd. also sells lab-propagated plants.

The key - no matter where you purchase them - is to make sure they have been lab propagated, which ensures they were not taken from the wild. Reputable companies should be happy to explain how they do so.

Pink lady's slipper can be the most difficult native orchid to grow, Leopold said. It's particular about acidic, sandy soil. High fertility levels often hurt these plants because they are adapted to lower levels. Fertilization will often kill the fungi which will then then kill the orchid. "If you are really good at gardening, this is the ultimate challenge," he said.

The yellow lady's slipper, however, is slightly easier to grow. It will grow in shade but will disappear in full shade. It grows best in humus-rich soil and flowers in May.

For the best luck in growing lady's slippers in the garden, Leopold recommends the Kentucky Lady's Slipper, which is native to the eastern United States. He grows his at the edge of a blue spruce, where it gets a lot of morning sunlight.

"I fertilize it, I mulch it, I baby it and it's rewarding me by almost every year doubling in size." It likes loamy soil with lots of mulch, not sandy or acidic soil. It responds well to organic amendments. It is for sale at Garden in the Woods.