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Successful landscapes begin with the selection of plant materials appropriate for the site conditions. This fact sheet is designed as a reference guide to woody plant materials that tolerate tough sites. Recommendations are made for trees and shrubs that survive better than others in the following soil and site conditions: poorly drained soils, droughty soils, alkaline (high pH) soils, compacted soils and sites exposed to deicing salts. Detailed descriptions for each of these conditions are provided on the next page. The map shows the six major ecoregions in Minnesota. Minnesota's Ecoregions Southeast Central Northeast North Central Northern Tallgrass Prairie Southwest

Tough Site Categories

Poorly Drained Soils. A well-drained landscape soil should drain a 24-inch column of water in 24 hours or less. To determine if your site is well-drained, conduct a percolation test by augering or digging a hole 24 inches deep. Fill the hole with water and allow to drain completely. Fill the hole with water a second time soon after the first filling is completely drained. The second filling should take 24 hours or less to completely drain. If the hole still contains water after 24 hours, it is considered poorly drained . . .to some degree.

Droughty Soils . These soils are characterized by excessively rapid percolation rates (24 inches of water drains in a few minutes or less), and a low organic matter content(<1%) that can be determined by a lab soil test.

Alkaline Soils . An alkaline soil will have a pH greater than 7.0. Most trees perform best in acidic soils(<7.0) to slightly alkaline (7.5).

Compacted Soils. This is primarily a problem with fine-textured soils (clays, silts). Compaction may be gauged with a penetrometer or with a digging spade. If a spade easily penetrates the soil to a depth of two spade blades (about 18 inches), the soil is not compacted. If the hole needs to be dug with a pick axe, it's a compacted soil. Soil compaction will result in stressed plants, performing less than ideally and more likely to suffer from secondary problems such as diseases and insect pests.

Deicing Salts. Deicing salts damage plants in two forms: accumulation of deicing salt run-off in the landscape soil, and drift of deicing salt spray. Salt spray damage is the most widespread and troublesome in Minnesota. Trees and shrubs within 60 feet of high-use roads are most at-risk for this type of damage.

Native trees and shrubs are coded 1 - 6, following their name, to match the ecoregion/s where they are native. Bold lettering indicates an evergreen species. Y= yes, I= intermediate, S= sometimes.