Planning farm shelterbelts

Introduction

Planning Your Shelterbelt

Proper planning of a shelterbelt involves reviewing your present requirements, assessing your future needs, estimating the quality of existing shelterbelts and planning new shelterbelts for unprotected areas of the farm.

Begin by mapping out your farm using a scale of 2.5 centimetres = 30 metres or 1 inch = 100 feet, marking locations of existing trees, sloughs, buildings, farm access roads and power lines. Next, draw in the prevailing wind directions and note areas where excessive snow accumulation can cause problems.

To eliminate problems with snow buildup, keep all trees at least 30 metres (100 ft) from main buildings and driveways. Mark this distance around the perimeter of the yard plan to indicate the proposed locations of the shelterbelts (Figure 1).

Shelterbelt Design

Once you have determined the location, decide on the number of shelterbelt rows required to properly protect the farm. Up to five rows of trees are recommended on the north and west sides to provide protection from prevailing prairie winds. Two or three rows are usually adequate on the east and south side. Field access roads should be located in the east or south comers to allow summer air flow through the yard.

The farmstead shelterbelt should be tall, fast-growing, long-lived and dense in both summer and winter. Accomplish this by using a variety of species, each possessing at least one of the desired characteristics. Refer to Trees and shrubs for Shelterbelts for a description of trees and shrubs used for shelterbelts.

The outside row of a shelterbelt acts as a snow trap and should be a dense shrub such as caragana, villosa lilac, or choke cherry. The second row should be a fast-growing species such as acute willow or Manitoba maple. Long-lived species such as green ash, bur oak or Manitoba maple should be planted in the third row. The fourth and fifth rows, which are closest to the yard, should be tall, dense and long-lived. Conifers such as Colorado spruce, white spruce and Scots pine are suitable here. In addition, they benefit from the early protection provided by the outer rows (Figure 2).

Poplar and Siberian elm are fast-growing but short-lived on the prairies. If they are used in the shelterbelt, plant them outside the shrub row to provide early protection for the slower growing species and to facilitate removal of dead trees.

Although five tree rows are recommended for effective shelter, not all sites have sufficient room for this many rows. For confined sites, reduce the number of rows rather than planting too close to buildings or reducing the recommended spacing between the rows . If you are limited to two rows, plant one row of dense shrubs such as caragana, villosa lilac, or choke cherry, and one row of dense trees such as spruce. Also you may wish to combine a shrub with a green ash to increase the shelter by the outer row.

For more detailed description of tree species, refer to the "Trees and Shrubs for Prairie Shelterbelts" brochure.

NOTE: The root systems of some species, including willow, Siberian elm, maple and poplar, are very fibrous and competitive. These species should not be planted next to gardens or orchards.

Species Selection

Selection of appropriate tree and shrub species is very important. Each species has its own characteristic height, width, density, longevity, growth rate and resistance to insects and diseases (Table 1).

Shelterbelt Spacing

The spacing recommendations within and between rows is very important (Table 2). Remember, you are planting seedlings which will eventually develop into mature trees, reaching heights up to 18 metres (60 ft) and widths up to 12 metres (40 ft). Leave sufficient space between shelterbelt rows to permit the passage of maintenance equipment. Correct spacing between trees and rows allows adequate light, moisture and nutrients for proper growth.

Recommended minimum spacings between rows

When you have selected appropriate tree species and determined the number of rows, draw them on your farmyard plan. Attach a copy of the plan with your application for trees. The Shelterbelt centre accepts applications on a first come, first served basis, starting June 1 for delivery the following spring.

Shelterbelt Planning Around Dugouts

A shelterbelt can be designed to trap snow to help replenish water supplies and reduce the hot, dry winds that increase evaporation from dugouts. Trees should be planted at least 15 to 30 metres (50 to 100 ft) from dugouts depending on drainage. If the land slopes away from the dugout, then plant the shelterbelt closer to allow the trapped, melted snow to drain into the dugout. Do not plant any closer than 15 metres (50 ft) to prevent the shelterbelt from using stored water and contaminating the water with foliage.

Multiple rows of shrubs, such as caragana, lilac and chokecherry, provide a dense effective snow trap. Conifers, like Colorado spruce, white spruce and Scots pine, can be used for greater wind protection.

Points To Consider In Planning

1. Keep all trees at least 100 ft from roads, buildings, etc. Check with your Rural Municipality regarding tree planting regulations next to road allowances.
2. Plant only as many trees as you can care for. More trees are killed by weeds and grass than by any other cause. Refer to Weed Control in Shelterbelts.
3. Avoid any access roads or openings in the shelterbelt which will allow the prevailing winds to blow into the yard site.
4. Protect shelterbelts from livestock; fence off the planting if necessary.
5. Include fruit-bearing shrubs, such as chokecherry, buffaloberry and sea buckthorn,in the outer row to benefit wildlife.
6. Ensure dead trees are replaced as soon as possible.

For more information contact:
PFRA Shelterbelt Centre
Indian Head, Sask. S0G 2K0
Phone: (306) 695-2284 or Fax: (306) 695-2568
E-mail: pfratree@agr.gc.ca