THE POLLINATOR STUDY:
How Christmas Tree Growers Can Create Safe Habitat for Pollinators
Opportunities for Habitat
Creating habitat for pollinators in Fraser fir Christmas tree fields requires balancing the needs of Christmas tree production with benefits to the environment. Flowering groundcovers are the goal to providing habitat for pollinators and predators. However, limiting weed growth is a requirement for Fraser fir Christmas tree production.
Weeds compete with slow-growing Fraser fir, especially when they are young. Weeds make it hard for workers to move through trees if they are too tall and to do common tasks like shearing trees. Some weeds such as poison ivy or briars are also a health issue for workers. When a pesticide application is required, the presence of tall weeds will keep the spray to the targeted area on the tree. Christmas tree wholesale buyers also prefer to see fields that are kept clean of weeds. They mistakenly think that fields with a lot of weeds growing in them are not being taken care of.
Having pollinators present in Christmas tree fields is also a problem when trees need to be treated with an insecticide. Virtually all insecticides are toxic to bees, though they vary in how toxic and what effects they are likely to have. Even organic products such as Spinosad are highly toxic to bees. Therefore, care must be taken when using an insecticide when bees are actively foraging.
Of course the pay-off in having a diverse groundcover around Christmas trees is increased biodiversity. Predators and insect parasitoids are present in higher numbers in fields with groundcovers and flowering field borders. The following are some tips for growers on how to help pollinators, promote natural pest predators, and yet have a well-managed Christmas tree farm.
Suppress Groundcovers with Herbicides
Fields where weeds are suppressed with low rates of herbicides such as Roundup (about 1/8th of the labeled killing rate) naturally shift groundcovers towards woodland perennials which support pollinators and predators. This has been proven in many fields throughout western North Carolina for the past ten years. Be sure to scout fields to know when and if a Roundup application is required so that weeds do not grow too large.
Allow Field Borders to Grow
Field borders along creeks, the edge of woods, and roads are perfect places to let nature take its course. By not using herbicides or mowing, these areas will naturally grow many flowering plants. To keep these areas from growing up in brush, mow every 2 or 3 years. These areas will provide food for wildlife, pollinators and many natural pest predators with very little effort.
Allow Field Roads to Grow
Keeping field roads mowed adds to the expense in a Christmas tree farm. And these roads, during the summer months, can provide habitat for pollinators and natural predators. The road pictured here had thistles and milkweed, and there were always many butterflies and bumblebees.
Manage Cut-Over Fields for Flowering Groundcovers
Several of the fields in the study had been partially harvested. Groundcovers in these fields could be allowed to grow a little taller without hindering production practices. These fields always had a lot of biodiversity and pollinator activity.
Be Aware of Honeybees
Christmas tree farms provide a lot of habitat for honeybees. In a beehives managed by Cooperative Extension personnel in Ashe and Alleghany Counties, the hive in the Christmas tree field outperformed the hive in Sparta, NC for honey production and brood. Protecting bees from harm from pesticides should be the goal of every Christmas tree grower. Click here to view tips for protecting bees in Christmas trees.
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