Tree Talk: ABC's of Planting Trees

Tree planting can take place anytime during the growing season. With the cool, rainy season we are experiencing, now is a great time to get some trees in the ground! Trees provide shade, wildlife habitat, beauty in the landscape, and add value to your property. It's tough being a tree in North Dakota, so follow these tips for a successful planting:

1. Locate logically - Select a site that will provide space for the tree – above ground and below. Roots need space, too. Select a small-statured tree like an amur maple, Japanese tree lilac or flowering crab for a small space or a location with overhead wires.

2. Choose carefully – Species diversity is the key to resiliency against pests and environmental challenges. Green ash is a hardy native species, but it has been over-planted in nearly every community throughout North Dakota. Emerald ash borer (EAB) has not been detected in the state, but has been confirmed in 35 states and will someday be here, too. EAB kills ash trees. Don't plant green ash – rather, consider one of these for shade: American linden, Prairie Expedition American elm, Prairie Stature hybrid oak, Northern Acclaim honeylocust or Prairie Torch hybrid buckeye. You may have to search to find these trees, but they're worth the effort.

3. Plant properly – Tree planting is an ancient art. Dig the hole WIDE and SHALLOW, just deep enough so the roots are located right beneath the soil surface. Roots need oxygen found in the upper topsoil to absorb water and nutrients. A deeply planted tree may survive, but cannot thrive. Remove the root ball from the container and set the plant on firm ground. If the roots are pot-bound, tease out some of the roots and slit the sides of the root ball with a knife - this sounds painful but it won't hurt the tree. If the hole is too deep, shovel soil back into the hole to position the tree so the tree roots are just beneath the soil surface. Note: the "crook" at the lower part of a young tree trunk is where the tree was grafted at the nursery. If the graft is not visible above ground on a newly planted landscape tree, it's in the ground too deep.

4. Fertilize frugally – Don't fertilize at the time of planting – it may cause root injury. A soil test will reveal if you need to fertilize at all. If you fertilize your lawn, the trees are getting the same treatment. Be careful with lawn weed killers, too. They can harm trees.

5. Water it well – Proper watering is the key to survival for a planted tree. Use a low-pressure hose to water and settle the soil. When done, the planting area should be well-soaked and moist backfill should barely cover the top of the root ball. Frequency of watering depends on the soil, not the calendar. Deep, infrequent watering is better than shallow, frequent sprinkling of the soil surface. Figure about 10 gallons a week for a new tree. Too much water will saturate the soil and deplete soil oxygen, which can literally drown a tree.

6. Mulch meaningfully – Mimic Mother Nature by placing an organic mulch of wood chips around the tree. A layer 3-4" deep, out to the dripline of the tree and away from the trunk (like the shape of a donut) will help conserve moisture, inhibit weed growth, and prevent mower damage. Organic mulch breaks down, adding nutrients to the soil. Replace mulch as needed.

Enjoy the satisfaction of planting and caring for a tree. You've just made the world a better place.