Let Your Trees Grow For Profit

According to consulting forester Jim Birkemeier, a properly managed hardwood tree, such as a red oak, growing in southern Wisconsin adds ¹⁄₂ " to its adult diameter each year. "Combine that annual growth rate with increasing premiums for larger, quality logs and generally rising stumpage prices, and you get total value growth rates of 20-30 percent a year for managed timber stands," he says. That's why the forestry emphasis at Jim's 300-acre Timbergreen Farm near Spring Green, Wisconsin, and other forested land he manages, is on waiting for trees to maximize growth before harvesting them.

"When I started in forestry 20 years ago, we had been taught in college that hardwood trees should be harvested at 14-20" diameter. And that's what we did," Jim comments. "Back then, landowners got about $16 for a 20"-diameter tree with 320 board feet of lumber in it. But if they had managed their forest and waited until now to harvest, that same tree would be close to 10" larger in diameter and should be worth about $650 because it's not only larger, but of higher quality [refer to the "added-value" stumpage chart below]. I've found that to get the most profit from your crop [timber] trees, they should grow to at least 24-30" diameter before harvesting."

That doesn't mean, however, that landowners shouldn't harvest some trees on a regular basis. "To give valuable crop trees [e.g., red and white oak, sugar maple, walnut, cherry, ash] room to grow, the woods need to be thinned of smaller and less desirable trees," he advises. "These can be sold for paper pulp, pallet wood, and even low-grade lumber. The object is to grow crop trees of different ages so you can have a continuing [sustained] yield as each group matures." (See the tree-thinning guidelines below.)

As an example of good forest management, Jim recently worked with a neighboring dairy farmer to do a "crop tree release harvest" on one small hillside. Overmature aspen and red maple were harvested for pallet logs, and 45 crooked and suppressed red oak trees were cut for saw logs. The 45 oak trees alone brought $4,600 from a sawmill. The remaining thinned forest on the hillside now is a magnificent stand of 18"- to 26"-diameter red oak crop trees free to grow larger and more valuable.

"Today, if landowners grow trees to their greatest yield potential, they'll benefit from more volume, higher quality, and continually rising prices," says Jim. "And to those who use wood, that also means a continual supply of top-grade lumber in the future. (For information, contact Timbergreen Forestry, S11478 Soeldner Rd., Spring Green, WI 53588)

Forester Jim Birkemeier follows these guidelines to thin the timber stands he manages:

• Allow 10' spacing for planted hardwood saplings. This gives you approximately 440 trees per acre. Maintain this spacing until the trees reach 8" in diameter, then thin to increase spacing to 20'.
• At 20" diameter, crop trees (either planted or in the woods) should have 35' of space between them, leaving about 36 per acre, plus under-growth shrubs and saplings.
• When trees reach 30" diameter, increase the distance to 50', leaving 16-20 per acre until harvest.

The trees cut in each thinning can be sold as lower-grade lumber, pulpwood for paper, and pallet stock. Later when larger, they sell as saw or veneer logs.