Why Fall Is the Best Time to Plant Trees

By Ann Asher

Every spring, garden centers fill with shoppers loading young trees onto trailers and into pickup trucks. It makes sense. The weather is warming, everything is turning green and planting season feels like it has arrived.

But ask an arborist or Extension horticulturist when they would rather plant a tree, and you’ll probably hear a different answer: fall.

It may seem backward at first, but in North Texas and central Oklahoma, experts widely consider the months between late September and early winter the best time of year to plant most trees. The leaves may be getting ready for winter, but the roots keep growing below the surface long after top growth has slowed. That lets a young tree establish itself before the next hot summer arrives.

That’s a tremendous advantage in a region where summer temperatures routinely climb into the 90s and beyond.

A newly planted tree has one job: grow roots. A tree planted in spring has only a short window before it must also support a flush of new leaves while enduring months of heat, drying winds and occasional drought. That combination can put significant stress on a young tree before its roots have had time to spread into the surrounding soil.

A fall-planted tree has a much easier assignment.

As air temperatures cool, the soil often stays warm for weeks. Those conditions encourage continued root growth without asking the tree to produce new leaves or long shoots. Instead of splitting its energy between growth above and below ground, the tree can put most of its effort into building a healthy root system. By spring, it has settled into its new home and is better prepared for warm weather. Research and recommendations from both Oklahoma State University Extension and Texas A&M AgriLife Extension support fall as an ideal planting season for many landscape trees in this region.

You still can’t dig a hole and walk away.

Choosing the right location is just as important as choosing the right tree. Consider the mature height and spread, not the size of the sapling you’re bringing home. A small oak, pecan or cedar elm may fit comfortably today, but in a few decades it could tower over a house or tangle with utility lines if you plant it without a plan. Likewise, trees that prefer moist soils may struggle in dry, exposed spots, while drought-tolerant native species often need far less maintenance once established.

When it’s time to plant, dig a hole two to three times wider than the root ball, but no deeper.

One of the most common mistakes homeowners make is planting too deep. The point where the trunk begins to flare into the roots should sit at or just above the finished soil level. Burying that flare can lead to poor growth and long-term health problems.

Backfill with the native soil that came out of the hole instead of rich potting soil or heavy amendments. It may seem like a kindness, but surrounding the roots with very different soil can discourage them from growing outward into the ground where they’ll ultimately need to survive.

Water thoroughly after planting, then keep watering deeply as needed during dry periods through fall and winter. Even dormant trees need moisture while their roots continue to develop. A layer of mulch two to four inches deep around the base helps conserve soil moisture, regulate temperature and reduce weed competition. Keep the mulch pulled back several inches from the trunk. The familiar “mulch volcano” piled against the bark may look tidy, but it can trap moisture, encourage decay and attract insects.

If you’re unsure what to plant, consider species well adapted to the Southern Plains. Bur oak, chinkapin oak, cedar elm, Shumard oak, bald cypress, Mexican plum, eastern redbud and native pecan are all excellent choices in many parts of North Texas and central Oklahoma, depending on soil conditions and available space. Native trees generally handle local weather extremes better and provide valuable habitat for birds, butterflies and other wildlife.

Planting a tree is one of the few gardening projects that benefits future generations. Long after this year’s tomatoes are forgotten and next season’s flowers have come and gone, that tree will still be growing. It may shade a porch, shelter wildlife, lower summer cooling costs or become the backdrop for family photographs that haven’t been taken yet.

Spring may get most of the attention, but fall gives young trees their best chance to thrive. Give them a strong start now, and they’ll spend the years ahead returning the favor.