Purdue News

Spring's the best time to plant a tree

In fact, some trees should only be planted in the spring, said Michael Dana, consumer horticulture specialist with the Purdue Cooperative Extension Service.

The benefits of trees are well-known. They provide oxygen, trap carbon dioxide, keep wildlife safe from pets and predators, shade the house from summer sun, block winter winds, beautify the neighborhood, and raise property values, Dana said. But putting the right tree in the right place takes some planning.

"Take the long view," Dana said. "Envision a full-grown tree at the proposed site and ask yourself: 'How tall will it grow? 'How wide will the canopy spread?' 'Where will the roots grow?' 'What might go where the roots will be?' Not anticipating tree size can be a big mistake."

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.

He also recommended checking the soil of the proposed tree-planting site before selecting a tree so you can better match the tree to ground conditions. Soil that is heavy, mostly clay or compacted will limit the choices of tree species.

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

"It's important to match the tree to the landscape rather than try to force a favorite 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 specialist suggested these other tree planting tips

• Handle the plant carefully at all times; it can be damaged by rough handling.

• Make the planting 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 construction sites, where the soil is probably 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.

• 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.

• Place a 2- to 4-inch thick 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. Thoroughly soak the tree root system once every seven days, but don't water a little bit every few days. Tree roots need water, but they need air too.

• If the tree has smooth bark, plan to wrap the trunk with a light-colored wrap in October to baby it through the first winter. Remove the wrap next April.

To the Purdue News and Photos Page