Over the past 20 years PINE WILT has killed so many Scots or SCOTCH PINE (Pinus sylvestris) trees in the Midwest that Extension Specialists and arborists in many Midwest states no longer recommend planting this once popular species as a landscape or windbreak tree. Some experts even predict that we will not have any Scots pine trees in eastern and central Nebraska within 5 to 10 years. No cure has been found so far. High value trees can be protected with a series of trunk injections of Greyhound (abamectin is the active ingredient). This is a preventative treatment and very expensive.  

          Other pine species are occasionally killed by pine wilt and display a similar pattern of symptoms. The disease appears occasionally in Austrian pine (Pinus nigra), Jack pine (Pinus banksiana), Mugo pine (Pinus mugo), and Red pine (Pinus resinosa). It is rarely found in White pine (Pinus strobus) and never found in spruce, fir, juniper, or red cedar.

          Tree age influences the risk of pine wilt.  Almost all cases of disease have appeared in trees more than 10 years old. Therefore, pine wilt has not had a major impact on Christmas tree plantations of Scots pine or Austrian pine.

          In Part I, I wrote about this fatal disease of pines in the Midwest, the pinewood nematode (Bursaphelenchus xylophilus), and the pine sawyer beetle (Monochamus carolinensis) that carries the nematode. I also mentioned that the disease has been found in some Austrian Pine trees. In Part II, I described some trees that could be used as replacements for the Scots pine and Austrian pines. Today I want to talk about how to decide what tree to plant and how to plant that tree. This section is also applicable to deciduous trees that lose their leaves) as well as conifers. As with Part II most of this material comes from the Nebraska Statewide Arboretum and an article by Justin Evertson.  

          He recommends: “Before selecting that replacement tree (or a new tree for your landscape), get some ideas from established landscapes:

1.     Drive around and see if you can find a tree you like.  Pay attention to what you like and what you don’t like. Also pay attention to height, width, form, and seasonal color if any. You may want a dwarf variety so it does not outgrow its space.

2.     Be sure and pay attention to drainage in your landscape and where you want to plant the new tree so it does not sit in water after a rain.

3.     Can the tree stand dry living conditions, or does it need lots of water? And if in the lawn, will it tolerate a sprinkler system? Your grass takes a lot more water than most trees like.

4.     Find out if the tree you like needs full sun, partial sun, or shade.

5.     You may want to get a soil analysis so you know that the tree you like will survive in your yard or acreage. Making any changes after a tree is planted is almost impossible.

6.     When planting your new tree, do not plant too deep. Dig your hole just deep enough. Do not go any deeper or roughen up the bottom of the hole. If you do the root ball will settle and be too deep. Dig your hole at least twice as wide as the container or “balled and burlapped” root ball. The first root should be only two inches below the surface of the soil. If necessary remove some of the soil from the top of the root ball to find the first root. If you see a tree coming out of the ground like a utility pole, with no flair at soil level, it is planted too deep. Trees planted too deep will always be under stress and will more likely have disease and insect problems.

7.     Add wood chips around the tree. Go out at least two to three feet from the trunk. This will help to retain moisture and keep the roots from drying out.

8.     Do not try and grow grass up next to tree. This stresses the tree and makes the trunk more likely to be damaged by a mower or weed whip. 

          “When planting evergreens, remember that most species prefer well-drained soils. In fact most evergreens will struggle in heavily irrigated, turf-dominated yards. In addition, evergreens almost always work better in groups, as backdrops or as framing elements. Be careful if planting in the front yard especially near sidewalks, intersections, or picture windows where they might eventually outgrow the space.”

          When planting any new tree, measure the space to make sure that the mature height and width of the tree is not too big for the site. Many times that small tree is placed too close to the house or another structure. Read the tag on the tree and measure to make sure. When I planted the Colorado Blue Spruce in my front yard, I measured out from the house so I knew how much room I had to the sidewalk. The small tree looked lost but now, 40 years later I am glad I did the measuring.

          New trees need to be watered in, but be careful, as many new trees are killed by over watering. Before watering your new tree, make sure the soil is not saturated from the previous watering. Also, check to make sure that the roots do not dry out. If you plant a tree and then go on vacation, make sure someone is checking on the tree and waters as needed.

          I want to thank Justin Evertson again for permission to use his articles in this series, and for reviewing and correcting the information. For more information on tree selection, tree planting, and tree care, you can reach Justin and the Nebraska Statewide Arboretum on the internet at “”. Also at this web site are links to colored pictures of trees.

          You can also contact your County Extension Educator or go on line to On the left hand side you can type in the name of a disease or the name of a tree then click on search. A list of publications will appear. You can read those you want and/or download them to your computer or print them for your files.

          Or you can go to This is the web sight for the Nebraska Forestry Service which is a division of the University of Nebraska-Lincoln. In the upper left hand corner in the search box type in “pine wilt” or the name of the tree you want information about. A list of publications will appear. You can read those you want and/or download them to your computer or print them for your files.

Copyright 2007