Purdue News

Fall's a fine time to plant a tree

"Not only are fall weather conditions milder compared to most summers that follow a spring planting, but the trees may also be on sale," said Rita McKenzie, an urban forestry specialist in Purdue's Department of Forestry and Natural Resources.

The first step is to get a soil test. Use the information on nutrients, organic matter, soil acidity and salt content to determine which species are best suited to your yard, McKenzie said.

Choose carefully, though, says Purdue Extension horticulturist Mike Dana. It's a large and expensive piece of planting, and putting the right tree in the right place means thinking ahead. Envision a full-grown tree at the proposed site. How tall will it grow? How wide will the canopy spread? Where will the roots go? What might go where the roots will be? A large stump next to the house is a good sign somebody guessed wrong. Trees need room to spread both roots and branches.

"The failure to anticipate tree size is the most common mistake," he said.

Dana follows the "look up, look down, look all around" rule. Keep in mind power lines, lines of sight in front of windows and doors, and underground utilities and drains that might block roots or be blocked by them.

Available sunlight, moisture and cold hardiness are other considerations to keep in mind.

"It's important to match the tree to the yard rather than try to force a favored species into unfavorable conditions," Dana said. "The choice of plants may be more limited, but the likelihood of long-term plant survival with minimal maintenance is much greater."

The specialists suggest these other tree planting tips

• Handle plant carefully at all times

• Follow the recommendations on planting: Different species have different needs. Some trees should be planted only in the spring. Check the tree's cold hardiness with the nursery.

• Make the hole at least one foot wider than the root ball, and the same depth as the soil ball or the root container. Loosening the surrounding soil will benefit trees planted at new homes, where the soil may be compacted.

• Prune only broken branches, leaving the branch collar (swollen area where branches meet) intact.

• Never plant deeper than the depth the tree was originally growing. Place the tree in the hole and add soil to the original growing level indicated by a dark color and different texture on the trunk. Use only soil to fill the planting hole -- do not add fertilizer.

• Take proper precautions when planting in heavy, poorly drained or sandy soils. Firm the earth around the tree to hold it in place and eliminate air pockets. Don't use your feet to tamp soil down, as this could cause compaction and inhibit root growth. Settle the soil with water, adding more soil as necessary until the tree is firmly established. Don't add soil above the trunk root flare --the junction between trunk and roots.

• Do not fertilize the first year except at the first watering. Place a 2- to 4-inch layer of mulch around the tree -- but not against the trunk -- to conserve moisture, protect the roots from temperature extremes, and keep down grass and weeds that may compete for water and nutrients. Leaf litter, shredded bark, peat moss and wood chips are good choices.

• Water diligently for the first season. Transplanting is a shock to the tree's system, and it needs water to persevere.

  Wrap the trunk of new tree with a light-colored wrap in October to baby it through the first winter. Remove the wrap in April.

  CONTACTS: Rita McKenzie, (765) 494-3625

  Mike Dana, (765) 494-5923; e-mail, Mike_Dana@acn.purdue.edu

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