Tree Talk: Fall tree tasks

One of the sure signs of autumn is fall foliage in the landscape as woody plants prepare for winter. Here are some things that you can do to prepare your trees for the long dormant season:

1. PLANT. Fall is a great time to plant trees. While selection at nurseries may be limited, trees are often on sale in the fall. Cooler temperatures enable plants to acclimate to a new home without the stress of high air and soil temperatures. However, trees need time for roots to establish – at least a month before soil temperatures dip below 40 degrees. See the map which outlines the latest recommended planting dates for fall tree planting in North Dakota.

2. CHOOSE CAREFULLY. Make diverse species choices that are suitable for North Dakota's alkaline soils – don't buy something just because it seems like a good deal. Most landscapes can use more honeylocust, bur oak and Dutch elm-resistant American elms and hybrids. Don't plant more green ash, the most dominant tree in our state's urban and rural landscape. For winter interest, choose a tree with interesting bark (river birch or hackberry) or fruit that hangs on the tree beyond fall (Consider mountain ash or check out the selections of flowering crab).

3. DON'T FERTILIZE newly planted trees, and only apply slow-release fertilizers on established trees. Applications of nitrogen will encourage new tree growth which won't have a chance to harden off before winter. If you're fertilizing your lawn, you're also fertilizing any trees nearby. Trees have a root spread equal to or greater than the height of the tree. Avoid weed-and-feed formulations. No need to spread weed killer across the entire lawn along with a fertilizer application.

4. WRAP newly planted trees with brown kraft paper, starting at ground level and working your way up the tree to the first branch. White plastic tubing can also be used. This protects young trees from winter sunscald on the southwest exposure of the trunk and will also deter rodents from feeding on the bark. Trees most susceptible include thin-barked fruit trees, mountain ash, honeylocust, maples and linden. Tree wraps should be removed in the spring so the bark can "breathe."

5. MULCH. Replenish organic mulch like wood chips around the tree, and keep the chips three inches deep and three inches away from the trunk to avoid critter habitat next to the tree. The mulch helps to slow the change in soil temperatures and protects the roots.

6. WATER trees before freeze-up. Tree roots remain active until soil temperatures dip below 40 degrees. Watering is especially beneficial for evergreens, which transpire tiny amounts of moisture through their needles throughout the winter months.

7. HERBICIDE APPLICATIONS should be done with caution around trees. Herbicides are most effective on lawns in the fall, but some herbicides can be detrimental to tree roots, especially with repeat applications. Spot spray, if possible. Learn to tolerate a few weeds – a diverse habitat is pollinator-friendly!

8. PRUNING is best done when trees are dormant, so leave that task until early spring. Routine pruning in early spring before buds swell enables the tree to naturally seal off pruning wounds most effectively. Broken branches should be properly pruned as soon as they are noticed. Don't use pruning sealer, tar or paint on any tree cuts or wounds. A proper pruning cut doesn't require sealer. With a bit of patience, you can outgrow a bad haircut but no amount of sealer or paint can fix a bad pruning cut.

Trees are an investment and play a vital part in our home landscapes and in our communities. Trees are worth caring for, every season of the year.