Celebrate Earth Day with a Christmas Tree

This week while scouting a field for twig aphids and mites, I came across this little nest full of eggs. It reminded me of how Christmas tree fields are home to many creatures -- a perfect reminder of Earth Day.

The most important creatures that tree growers invite into their tree fields are natural predators, brought in when ground covers are managed rather than killed. The next photo is from a field I was also in last week, showing a diversity of flowering ground covers.

That means that tree growers don't have to purchase natural predators like the lady beetles sold here for home gardens. Predators are attracted to the diversity of flowers and insect activity in the ground covers and will feed on any aphids or mites found in the Christmas trees themselves. It's free pest control.

One of the lessons from the Extension organic field in Alleghany County has been that the ground covers that come in when low rates of Roundup are used are far superior to all the grass that grows in the organic trees. After all, we grow grass in our lawns because grass tolerates mowing. Mowing ground covers in the organic trees has promoted grass and actually decreased biodiversity in the ground covers as compared to the lower portion of the field where conventional practices have been used up until this year. In this photo, you can clearly see the line where the clover stops and the grass starts. That's the line between the trees that have been grown organically since 2008 and those that are switching to organic production this year. Mowing promotes grass and it has certainly taken over to the detriment of the trees and the natural predators as well. (For those wanting to grow Fraser fir organically, it will be important to plant clover and other beneficial ground covers in a field the year before the Christmas trees are set -- something that wasn't done on this site. But that's for another blog entry!)

These ground covers, however, are also forage for bees. Clover, wild mustard, and purple deadnettle especially bring the bees in. Protecting bees can be as simple as choosing the time of day when you spray with an insecticide. Spraying trees in the late afternoon or at night for mistblower operators, is a good way to avoid problems with bees. Switching pest control to the fall is also a good way to avoid problems with bees. Be aware if someone has a commercial or even a hobby hive near your tree field. For fields close to bee hives, a mid-March application of horticultural oil will control most Fraser fir pests without causing a problem with bees at all.

April 22 -- Earth Day -- might seem like an odd time to think about Christmas trees. But those involved in the Christmas tree industry in western North Carolina know that every day is Earth Day in a Christmas tree farm!