Successfully Planting Black Walnut Seedlings

If any tree qualifies as a multi-tasker, it’s the black walnut. Black walnut seedlings grow into exceptional shade trees highly valued for strong, durable and beautifully grained wood. And in about 10 years, their first delicious, healthy nuts are ready to harvest.To learn all about planting these remarkable trees, read on!


Things to Consider before Planting

Let’s begin with the “don’ts.” Black walnuts are particular about where they grow. Don’t plant them if:

  • You’re outside USDA plant hardiness zones 4 through 9.
  • Your temps don’t fall into the 33° to 45°F(0.55° and 7.2°C) range for at least 1400 hours each winter. The trees need these chilling hours to produce nuts.
  • Your summer temps often hit 100°F (32.2°C) for extended periods.
  • Your frost-free growing season is less than 140 days.
  • Your soil drains poorly, or the seedlings’ roots won’t be able to penetrate at least 10 feet without encountering hardpan.
  • You envision growing certain things within a 50-foot radius of the seedlings. Black walnuts release a chemical lethal to a long list of plants.

If no “don’ts” apply, you can start growing black walnut seedlings with a reasonable chance of success.

Selecting Your Seedlings

Plant your seedlings in spring. Preferably, get ones grown at a local nursery; otherwise, choose a grower no more than 50 miles north or 200 miles south of you. Purchase seedlings measuring 3/8 inches or more in diameter, 1 inch above their root collars.

Preparing Your Site

To prepare your site, loosen the top 27 inches of soil with a rotary tiller to eliminate weeds and help the seedlings root. Space seedlings grown for their nuts 12 to 17 feet apart. For timber production, 10- to 12-foot spacing is better.


To plant your seedlings:

  • Dig holes the same depth as the seedlings’ containers and wide enough to spread their roots without bending.
  • Hold a seedling upright in its hole and begin refilling. Stop halfway and firm the soil with your foot.
  • Add more soil and continue firming until the rootball is just covered and the seedling feels secure.
  • Spread the remaining soil over the hole to act as a mulch.
  • Water well and repeat for each seedling.

Protecting the Seedlings

Protect your seedlings from hungry wildlife with 5-foot plastic tree shelters. Secure the shelters with stakes. In the fall, raise them 2 to 3 inches so cold air will harden the seedlings off. Remove the shelters when the seedlings poke above their tops.