University of Vermont Extension 
Department of Plant and Soil Science

  Fall News Article


Dr. Leonard Perry, Extension Professor
University of Vermont
Fall is the ideal time to plant a tree--both for the gardener and the tree! The weather is cooler, so it is more enjoyable working outdoors. The tree also benefits because the soil is better able to retain moisture now than during the hot days of summer, so it becomes established easily. Roots will continue to grow in fall, even though tops are losing their leaves.  Trees will be in containers, so should be well-rooted, with little root disturbance during planting. 

When selecting a tree, consider your lawn's soil, sun, moisture, and temperature conditions, as well as your personal preferences regarding color, size, and leaf shape. Make sure the tree will be hardy in your area, especially if you live in mountains or a frost pocket. 

Make sure the site you pick to plant the tree will accommodate the tree after it has matured. Look up, down, and around.  Look up to see if the tree will interfere with any power lines as it grows.  Look down to make sure there aren’t any buried utilities or septic system.  Some communities require you to call Dig Safe before planting to ensure you don’t accidentally disrupt utilities, or worse get injured.  Look around to make sure the tree, as it grows, wont crowd other plants or buildings.

Before you plant the tree, test your soil for drainage. Dig a hole, fill it with water, and check it twice--once after 24 hours have elapsed, again after 48 hours. If the hole drains well in this time frame, the soil should adequately support a tree. If not, choose another site. If this is not possible, choose a tree that will tolerate occasionally wet and waterlogged roots.

Dig the planting hole two to three times wider than, and about as deep as, the tree's rootball.  The hole should be deep enough to plant the tree at the same depth, or slightly above the depth, it was in the nursery field. If you dig the hole too deep, the tree will settle as you water it. This places stress on the root system and trunk as it sinks below ground.  Before planting a potted tree, dig around the trunk gently to make sure you see the top roots, and place these just below the soil surface.  The "flare"-- where the trunk begins to spread out-- should be at the surface.

Obviously remove the container if plastic.  If the container is a fiber material, it is best to remove it too.  Some biodegrade, but others are treated to last a long period.  This will impede root growth.  These are easy to remove by slitting the sides once the pot is in the hole.  The same applies to burlap, some of which is treated.  At the least, remove all the twine tying the ball, as this will restrict roots and trunk growth before it degrades.

After placing the tree in the hole, refill it with the soil you initially removed. There are many different views on what to mix--or not to mix--into this soil. For example, it's probably not a good idea to add too much organic matter, especially if the native soil is very different or poor. This will encourage the roots to stay in the nice mix, and not venture out into the poorer soil.  You can add up to 20 percent compost or peat moss or similar.

You need to make sure the soil pH is right before planting.  Soil test kits are available from local Extension office, and many garden and feed stores, and results will tell how much of what may be needed.  Usually in eastern states you may need to add some lime to sweeten the soil, or raise the pH.  It's also good to add a small amount of phosphorus at planting, such as from rock phosphate (organic) or superphosphate, as phosphorus doesn't move in the soil and won't reach roots otherwise. Just use a small amount, such as a couple tablespoons for a 5-gallon bucket of soil.

As you refill the hole, gently tamp the soil to remove air pockets and establish good contact between it and the roots.  Gently is the key word.  Stomping it tight will destroy soil structure.  Leave a small trough on the surface, away from the trunk, to hold water.  Then water deeply, perhaps a couple gallons of water for a 10-gallon hole (amount of soil dug would fill a couple 5-gallon buckets).  Water weekly if it doesn’t rain at least an inch during the week.

Don’t fertilize until spring to avoid stimulating new growth.  Then you can use special fertilizer tree stakes, or simply sprinkle some fertilizer around the tree but away from the trunk.

Remove any grass within a couple feet of the trunk.  This will keep mice away from the trunk in winter, reduce competition with tree roots for nutrients, and avoiding weed trimming injury to trunks.  Add a couple inches of organic mulch on this area, but not next to the trunk.  Mulch, especially the deep mulching often seen that resembles a volcano, will encourage rots on the lower trunks and other problems.

Finally, stake the tree to avoid shifting in the wind.  Use a couple sturdy stakes at minimum, three for larger trees, equally spaced around the trunk and a foot or two away.  Use special tree twine or cloth, or rubber hose protectors over wires, to avoid trunk damage. 

If single trunks, placing a tree guard on them during winter will prevent sunscald injury, and chewing damage from mammals and mice.  These are usually plastic sleeves, a couple feet tall, that wrap around the trunk, and can be removed during the summer. 

Tight on space?  Then consider one of the smaller species or cultivars (cultivated varieties).  There are some nice selections of dwarf conifers (cone-bearing evergreens) in various leaf colors and shapes that fit well on smaller properties. 

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