If I were to have a Native American name, I bet it would be Josh Breakingwind. I do not have a man cave at my house (cue the sad music), so I need a place to go to do my business-a privacy screen where wind may pass without notice would be lovely. Sadly, the traditional Midwestern windbreaks I have witnessed are lacking much design or thought, so as a follow-up to my privacy screen article, I thought I would take a stab at windbreaks too.
Drive along any country road and one will see that single or maybe multi-row, monoculture stretch of white pine or spruce along the western perimeter of a country lot. Often, these planted stretches are laid out in such a way as to be almost ineffectual. They could be so much more.
Why windbreaks? Well, besides the obvious desire to prevent the next Dust Bowl from passing through, you may want to push the prevailing winds during certain times of year up over your domicile, which wick the heat away from exterior walls otherwise. You might have a prized collection of very rare and fragile hootenanny plants (never ever heard of it? I told you they are rare), and so you desire to create a nice little microclimate.
There are several things to consider when planning a windbreak, including (and I am totally stealing this from the link provided):
- Appropriate sighting
- Species selection
Let us start with appropriate sighting. As with all designs, start with the purpose of planting a windbreak. Do you want to prevent all gusts from passing through, or only during certain times of year? If you are not sure, checking out a wind rose online is a good place to start. These provide by the month and year the wind direction and speed. You might want to discourage winter winds, but encourage warmer air mass movement to reduce frost damage. Think this through and plan accordingly.
Now a word or three about spacing. Species planted in a windbreak are meant to reduce wind speed by up to 80% (come on, be a nerd and do the actual calculation!) and thus are planted closer together than normal. Know the area of protection you want to create and then pick your plant height and windbreak length accordingly.
Now a word about shape. The traditional Midwest approach is to plant a straight line (following the property line religiously) consisting of a single, or perhaps two, species matrix of similar height…tall. The problem with a typical windbreak design is multifold. One, if a strong gust hits the single height windbreak, those trees take the full brunt of wind, a single force hitting a wall. The result may be uproot trees. Another problem with a traditional approach lies with all monocultures: disease exposure. Lastly, a windbreak with low diversity is of a single age, or nearly so. It is what foresters call a single class forest, and such forests, of course, die out. A multi-class forest has a diversity of plants maturing at different points. May I suggest a different approach, one that is both more aesthetically pleasing and functional. Try layering. Look at the shape of any wood lot and you will see a triangle or dome shape with mixture of species and forms. Shorter material like shrubs to the outside and taller, longer living species to the middle. This shape lifts the strong wind gusts up and over the tallest trees in a rather aerodynamic fashion.
Now a word about species selection. Focus on selecting diversity. Pick for different maturation rates, different textures and forms. Pick plants with more than one function: food for wildlife and you (maybe those deer will stay away from the vegetable patch), or perhaps timber for fuel or construction projects (check out coppicing).
Lastly, a word or eight about management. Do it. Do not plant and walk away.
Horticulture and Facilities Manager