Restoration of Douglas Hawthorn (Crataegus douglasii) in the Great Lakes Region

Crataegus douglasii.
Crataegus douglasii. Note long thorns. Fruit becomes black when ripe. Photo by Thaynel Tuason.

Hawthorn seedlings.
Future population of Douglas hawthorn. Photo by Angie Lucas.

Hawthorn seedlings.
Hawthorn seedlings. Photo by Angie Lucas.

Douglas hawthorn is a small treelike shrub in the rose family with white flowers that blooms May through June. It is most abundant in the west where it is found from Saskatchewan to Alaska, south to California and South Dakota. However, disjunct populations are found in the Great Lakes region in Minnesota, Michigan, and Ontario where it occurs along forest borders and in open areas such as forest clearings, shores, and rocky outcroppings. In the Great Lakes region, some threats to Douglas hawthorn include insect infestations, cutting back or destroying them in recreational areas, timber harvest, succession, and trampling by hikers.

In Michigan, the shrub is listed as a Special Concern species and is foundin 9 counties, 8 of which are in the Upper Peninsula. The shrub is best represented from the Keweenaw Peninsula. There are five current locations from the Pictured Rocks National Lakeshore in Alger County. On the Hiawatha National Forest, C. douglasii is known from only one location in Alger County, near the shores of Lake Superior at Bay Furnace campground.

Due to its rarity, Douglas hawthorn was designated in 2000 as a Region 9 Regional Forester Sensitive Species (RFSS) on both the Hiawatha National Forest and Superior National Forest in Minnesota. The purpose of this designation is to ensure the continued viability of Douglas hawthorn throughout its range on Forest Service lands. The 2006 Hiawatha National Forest Plan directed that one new population of Douglas hawthorn be established along with three other RFSS species. Seeds of Douglas hawthorn were collected from the site from 2000 and 2005. Attempts to germinate the seeds were conducted at the Hiawatha National Forest Native Plant greenhouse, located in Marquette, Michigan.

In 2007, the seeds were treated using cold moist stratification, a process where the seeds are mixed with an equal amount of moist perlite and then sealed in a Ziploc bag and stored in a refrigerator. This process mimics the natural germination of certain seeds. Some of the seeds were scarified (to lightly scratch the seed coat) using sand paper and in November of 2007, thirty seeds germinated in the bags and were planted in the greenhouse. Seeds that were scarified germinated more quickly, however, both scarified and non-scarified seeds germinated. The seeds were initially planted in containers that were 2 inches in diameter and 4 inches deep using a soil mixture containing perlite, vermiculite, dolomitic and calcitic limestone, and peat moss. Once the plants grew to about 3 inches, they were transplanted to larger containers by volunteers from Marquette Senior High School where they are currently doing very well.

Thirty new seedlings will be outplanted back at Bay Furnace where they will contribute to the continued viability of Douglas hawthorn on the Hiawatha National Forest. A disturbed area nearby the original population has been chosen for the reintroduction site. Outplanting of this species will be continued over the next three years to ensure the successful establishment of the new population as new seedlings germinate. Additional activities at the re-introduction site will include non-native invasive species control work and planting of other native plant species to enhance the habitat.