mathmatics of a windbreak..help

Ok fence is 21 feet from house, barbedwire with a cow pasture on the otherside. 

I do not want to plant the wrong things in the wrong places and just make the house colder.  I have ordered some trees for use in windbreak and some for planting in the woods. 

First off I ordered chryy trees including rainier, which are untryed in this area.  I want them to have all the very best af advantages. 

From the conservation I bought Norway Spruce, Picea abies.  $7 for 25 seedlings.  I also bought 25 Persimmon, Diospyros virginiana for $8.

Last is the a conservation bundle.  The only way to get the Paw Paws...  5 seedlings each of the following for a total of 30 seedlings: American beautyberry, flowering dogwood, paw paw, red osier dogwood, golden currant, and arrowwood for $15.

I was talked out of the mulberry but after reading t he "5 fave trees" topic I may add them to my order. 

I always search and try to reuse a topic when I have a question...I searched windbreak before starting this and found some neat new stuff to read. 

Well, people will probably need more info about what direction the fence is from the house.  North, South, East or West.

Also what about prevailing winds. 

You say this is for a windbreak along a Fence.  A fence line does not necessarily make the right position for a windbreak.  As you noted, you don't want to make the house colder so don't put evergreens between your house and the sun.

Hopefully some one with more experience in this particular subject will jump in once you have answered some questions beyond simply how far from the house the fence is.  Like, does the wind blow accross the cow pasture directly at the house?  And Which direction does the wind come from there?  Which direction is the fence from the house?

I'm having trouble finding a picture or diagram to add to the thread, but here is some basic math stuff about the height of windbreaks and their effectiveness downwind:

from the PDF available at this website:
http://extension.usu.edu/forestry/HomeTown/Energy_TreesandEnergy.htm

Wind protection extends downwind ten to twenty times the windbreak height. 

Snow drift (tumultuous circular wind patterns in general) will be worst at the downwind distance of at two to three times the height of the windbreak. 

The best windbreak diagrams I've seen (that I can't find right now!!) - if you have the space - advise a band of a few types of shrubs trees that gradually get taller and gradually get shorter again.  Like a pyramid.  That way the tall trees aren't taking the full brunt of the wind (can cause them to grow more slowly than you might like), and the shorter things help smooth out currents and further extend protection on the downwind side as well.  Evergreens are a good choice as they will offer the most protection during the times of year when winds are generally stronger (though that's not always true) but then you have to consider shading during the rest of the year (you mentioned not wanting to make your house even colder).  In a thick windbreak like this you can plant cropping trees and shrubs on the down wind side. 

Mulberry trees are great, but they drop fruit all summer long, and that's gotten them the reputation of being "messy."  They're fabulous over a chicken coop/yard, the birds will snap up any dropped berries and turn their yolks really bright orange.  Don't plant one over your sidewalk or anywhere you want to have a clean grass.  You'll hate it, unless you're really on top of harvesting the berries all summer long. 

This PDF seems good as well, talks about a lot of species options: 

http://dnr.wi.gov/forestry/publications/tip/WindbreaksWebLowRes.pdf.

marina phillips wrote:Snow drift (tumultuous circular wind patterns in general) will be worst at the downwind distance of at two to three times the height of the windbreak. 

By "worst" you mean "thickest," right? I wonder if it might not be all bad.

I could imagine arranging windbreaks to deposit thick drifts of snow to form a light trap, as a means of warming the house or brightening up a greenhouse.

I could also see some value in collecting it where it will be useful as it melts.

Ok, wait, I just cracked Patrick Whitefield's Earth Care Manual.  Pages of stuff on windbreaks.  I'll read it all and get back to this later, when the sun isn't out. 

Nix what I said about the pyramid, apparently that causes the wind to go right over the top because it's too aerodynamic.  You can get away with crops on the downwind (leeward) side.  A vertical edge to the wind is important to get the wind to go up and over the top of it.  The planting needs to be dense (but not too dense! for other reasons no more than 20-50% total closure), and go all the way down to the ground. 

If the canopy is open close the ground the wind nearest the ground will be squeezed and speed up as it passes under the tree - not the idea! 

The typical English combination, so says an Englishman, of a low wall backed by a line of trees is usually sufficient.  You want some wind to pass through the hedge or it will make MORE air turbulence on the downwind side. 

Sheesh there's a lot to consider.  This isn't even delving into species in detail.  Or what happens when you have multiple wind directions and multiple breaks to create....

In choosing species, you might watch them in the wind.

The more they move, roughly speaking, the more energy they are absorbing. The greatest benefit from them isn't re-directing wind, but absorbing energy from it, which happens as leaves flutter and branches bend.

there were quite a few studies of trees that survived the hurricanes a few years ago -- or you could just drive around your area and look at the condition of old healthy trees and note what kind they are.

I think the important thing about a windbreak is that you want the wind to blow through it but you want the plants staggered so they slow the force of the wind not block it entirely.  Otherwise a strong windstorm can lift the trees or blow them right into your buildings.

This happened to me during Ivan -- my neighbor's chinaberries are still empaled into my fence!

g'day jennifer,

i think we'd all need to know more up front, as has been said a fence line is not necessarily going to be the best line for a wind break. also with wind breaks your main target is to cut the ind strength down not stop it or cut too much that will cause other issues of wind coming over the break in a wave and being stronger. so for me i aim for 10 to 15% reduction. a wind break would need to be at least 2 rows of trees panted in a stagger with tall forest trees in a line and then shorter trees in the other line, the more rows can be the better but always looking at spacing and tree heights and room for wind to come through the line.

common width over here is 30 meters of well thought out tree sizes and spacing. over here we usually look to controlling the westerlies and southerlies, our trade winds are the South easterlies need for cooling in summer. also suggested do some online research there is sure to be something there.

len

Oh hey, Thanks all.  I have mentioned it before and forgot to put all the information in...

My home sits 21 feet off of my north boundry.  Not much room and maybe too close for a true windbreak...hence this topic.  I will be wanting to start here on the north west boundry...front (west) is 65 feet from the house. 

I want to do the best I can with this place as we plan to retire here.  It is a deep narrow place... I have a photo

http://davesgarden.com/guides/articles/view/108/

I wrote this article on windbreaks several years ago.

The recommended spacing for a windbreak is:

The suggested within-row spacing of trees and shrubs is 4 to 6 feet; 10 to 16 feet for evergreen trees, and 12 to 20 feet for deciduous trees. For between row spacing, distances of 10 to 12 feet between shrubs, 15 to 20 feet between shrubs and trees, and 15 to 20 feet between trees are recommended. Windbreaks should be at least 100 feet from the nearest building

Source:  Bruce Palmer.  Missouri Conservationist on line. 
http://www.mdc.mo.gov/conmag/1998/03/50.htm.

I hope this is useful.

They are called shelterbelts in the great plains.   Lots of info in of all places, the Kansas forest service.
http://www.grit.com/daily-commute/Save-Money-in-2009-Plant-a-Shelterbelt.aspx

Gary:  I think that article is an excellent description of what a shelter belt does and also points out that there is a long history of shelter belts among traditional farmers in this country.

Here is the USDA  reference link from that article.

ftp://ftp-fc.sc.egov.usda.gov/NHQ/practice-standards/standards/380.pdf

Ok "Ideally" I need 150 feet...I don't have but 21 feet...  what kind of spacing do you smart guys suggest?

Is this windbreak for protecting the house from cold north winds?  Are you also trying to create warmer micro-climates for spring and fall?    I know your climate well as I lived in eastern Kansas as a teenager.  If your house gets the full force of cold northern winds in the winter, I don't think a couple of rows of trees will help much.    From the photo it appears to be a one story house, if so I would consider building an earth berm on the north side of the house.  You could plant into that with dense shrubs, etc.    And of course add insulation to the north wall of the house.    Still might have room for a row of evergreens in that 21'. 

gary wrote:
Is this windbreak for protecting the house from cold north winds?   Are you also trying to create warmer micro-climates for spring and fall?    ... Still might have room for a row of evergreens in that 21'.   

Thank you so much Gary for seeing my dilema. 

I would like to do what I can to cut the wind down.  Warmer micro-climates would be great, slowing the wind at the house would be super... having to not look at neighbors, priceless.

Maybe catch snow and water it's self, including like the blueberries growing along with it?

Give the small animals a place to hid from hawks?  (thinking of using bunnies to graze dog yard)

I plan lots of additional insulation, blown in I think.  This will be #1 in cutting my heating costs I know.

I am planning, scrapping that plan, making a new one, and them modifying that...  I want this to be a great place for hubby and I, and also to show anyone interested in what can be done.

I will plant as much as I can around the house and yard...but do not want to make it worse... the reason I ask for your help.

I just want to plant lots of trees, I want a lush, yet low maintance, landscape.  I need reasons to lobby for trees and to make sure that when the dust settles I am in the right... Trees are good.

Grass is good when you raise horses.  Hubby thinks grass is better than trees and I waste time and money on trees.  Horses will destroy an amazing amount of beauty and effort.

g'day jennifer,

yeh i missed that distance factor, ok you need to create a break of sorts for those northern winds, but what is the vexing question really? i would  not like to see large trees that near a house. for the main even medium trees. so maybe we need to be thinking something that can't compromise the safety of the house and its occupants.

over here that could be achieved by using our native clumping bamboos (non intrusive root systems), so maybe something similar or a tree that might grow more vertical with multiple stems, but with a non invasive root systems, some of the willow family might suit as style of tree but then they can have invasive root systems that get into the foundations and sewer pipes. and the best may only be a single line?

will take lots of carefull thought and the seeking of research, what have others near you done in like circumstances?

len

21 feet is a very short distance for a windbreak..so you aren't going to have  a problem there..but your trees are going to grow rather slow..as spruce is a slow grower..

seeing as how you are in missouri, right?, might i suggest that you travel some dirt or gravel road in the spring right after the spring road grading is done..this would be the really country roads through forests..you will find that when they grade the roads in the spring ..seeling trees like red and white pine, canadian hemlock, spruce and cedars..will be thrown up in the dirt that is grades as they widen the roads each spring (at least they are here in Michigan)..and you can literally pull the seedlings up out of the piles of dirt..(they won't survive if left there so you aren't stealing forest trees)..

also black spruce grow wild in the swamps here ..oftentimes you'll find seedlings that are too close to adult trees that can easily be removed and as they are too close to the adult trees to survive..you also aren't being thoughtless in removing them yourself..

we have gotten a lot of local native trees this way..they'll also grow faster than nursery trees in your property..

a neighbor might have a propertly that he'll let you walk in the spring and gather seedlings as well..

look for areas that are thickly forested with evergreens..and watch for 6 to 8" tall seedlings at ground level..many of them will not survive int hedifficult situations of being too close to a road or another tree..but will do wojnderfully as your windbreak..

i have a beautiful windbreak of black spruce that wera about 2' when i put them in..and are now about 10' tall;...and i have a great mixed border of canadian hemlock, red and white pine, cedar, black spruce, norway and blue spruce and other trees..it is wonderful..

just thinkin' jennifer,

is there a neighbour on the other side of the fence? maybe they will let you grow a row of trees on their side as well to help the effects of your wind break? if you can get seedling free like that do it so long as those types of trees are suitable for the proximity to the house?

len

I have cows for neighbors on that side of the fence.  that line is the back line of a neighbors pasture just as my horses neighbor my other neighbor..

neighbor house, cows, -->21 feet<--my house, my horses, --->neighbors house,

who I do plan to offer seedlings to.

mmm maybe the farmer wouldn't mind you adding a line or 2 of trees, but i'd be suggestijng you do it yourself so you control the design to that extent. of course things like distance from the fence on his side (i'd suggest maybe around 10 meters) would need to be considered so he can do his fence maintenance and lessen the likley hood of trees falling onto the fence. if the wind break is done properly the right amount of trees then grass will still grow between the trees for teh cattle and also provide them with sahde.

if he did go for it you have the extra task of butting barriers around the young seedling trees or the cattle will eat them in most cases, these barriers would then need to be remove once the trees are grown enough to be out of the cattle's reach.

all work for you to do. just some thinking to help you work a sollution.

len

Thought I would bump this one to the top to go with the chapter six discussion of the permaculture book by Mollison.

I wonder how this lady faired?

Property line is 21 feet from house.  If dense trees which grow to 15 foot tall are planted 5 foot off property line, that gives almost enough clearance.  That 15 foot windbreak is trying to push winds to 30 feet high, but the point where it does so will be slightly downwind of the windbreak.  Where surface winds will start to lift from the ground, is about 30 feet windward of the windbreak.

if the house is 30 foot "deep" (in windward direction) and we plant dense 40 foot (eventually) 40 feet downwind of house (almost 6H downwind of the trees), when those trees start to get 30 foot tall, they will start to feel the effects of the wind.  At that point, those trees will be trying to effect wind 60 in front of them, which is about half way across house.  If they get to 40 feet, they will be trying to effect winds almost to where the 15 foot tall windbreak trees are.  I would think there is a a good chance from this handwaving, that the two windbreaks could work together to shelter the house.  But I don't think many people think of planting trees on the south side of a house to protect form north winds.

I have no idea about snow drifting in this scenario.  I have hoped to have software set up to model this kind of thing, but it isn't ready yet.