Green Horizons

Make plans now for planting trees next spring

By Hank Stelzer

Most forest landowners think about planting trees in the spring. Like planning your summer garden in the dead of winter, fall is the prime time to prepare planting sites and place seedling orders to be ready for spring.

Preparing Your Planting Site
Every spring, foresters usually get a call from a landowner: "I just finished planting seedlings. What herbicide can I use to kill the weeds?" Weed management in new tree plantings begins with proper site preparation the fall before planting. The objective is to provide new seedlings with a three- to five-foot vegetation-free area. This weed-free zone can either be a strip or circle. If planting in perennial sod (like fescue), the most effective way to kill existing vegetation is with a contact herbicide. Fall applications will provide more consistent control than spring. An added benefit is that your planting rows, or spots, will already be "marked" come planting time.

Chemical control can be improved by mowing the area to eliminate existing foliage and treating the tender (and more susceptible) re-growth.

Photo courtesy of Hank Stelzer

Start preparing to manage weeds in fall to ensure easier spring of planting seedlings.

Glyphosate (e.g., Roundup, Touchdown, among others) is the most effective contact herbicide for perennial sods. The recommended rate is dependent upon the type of vegetation (fescue, brome, bluegrass, etc.) and the particular formulation of the herbicide you apply. For tall fescue, the recommended Roundup rate is two quarts per treated acre. Remember that a treated acre is always smaller than an actual acre, because only the area around the trees is treated. For example, planting trees on a 10'x10' spacing is 435 trees per acre. If the plan is to prepare a 4'-diameter circle around each tree, then the treated area is 1/8 acre [3.14(2 ft)2 = 12.56 sq ft; 12.56 sq ft per tree (435 trees per acre) = 5,464 sq ft].

Always read the herbicide label at least twice: once before purchasing the product and again before application. Crop Management Data Systems (CDMS) provides an online service for downloading the latest product label. Head to www.cdms.net, find the "Services" tab on the top menu bar, and then click on "Labels/MSDS" from the drop-down menu. On that page, type in either the chemical name of the active ingredient or the product name to locate the product label, in the search bar.

I recommend adding a second herbicide containing sulfometuron (e.g., Oust XP) alongside glyphosate to take care of any late-season grasses and broadleaf weeds. Sulfometuron has both pre- and post-emergent activity. As with glyphosate, carefully read the label as rates do vary depending upon where you live and what species you intend to plant. In the Midwest, the Oust XP label will allow fall application rates of three to five ounces of product per treated acre on sites where northern red oak, white oak, ash (green or white), sweetgum or yellow-poplar are to be planted. These rates also provide some pre-emergent control the following spring.

Sometimes weed control in new plantings cannot be started until the spring of the planting year. If started early, before weeds show substantial growth, an application of a soil-applied herbicide at least two weeks before planting might help. But spring weather conditions are usually dicey at best and the risk of damaging actively growing roots of freshly planted seedlings is high if herbicide is not correctly applied. Many people think that mowing is a form of weed control when in fact, it is not. It actually stimulates grass and weed growth that competes with new tree seedlings for water and nutrients.

Another fallacy is that a one-time chemical application is enough. Research has shown that it takes at least three years of active weed control to ensure success. It usually takes two herbicide applications the first year: one to prepare the site and another around two months after spring planting. The second application is necessary because most herbicides lose their effectiveness around 45 to 60 days after application. Weeds grow all summer long, making the second application very important.

In subsequent years, weeds most likely will be controlled with just one application at the start of the growing season. The exception to this 'rule' is situations where the weed pressure is very high, then a second application will be needed.

Which trees grow well in my area?
More than 160 tree species call Missouri home. Regardless of where a tree is planted, provenance is of paramount importance in selecting plant material for a planting site. Trees grow best when seed or seedlings are from a local source.

Soils and climate create four broad tree-growing areas in the state that should be considered when selecting species. However, within each major area many varying sites must be considered individually for species selection.

Photo courtesy of Mark Coggeshall

This photo shows a 26 year old seed source study of white oak planted in southern Indiana. The two large trees on the left are from Mississippi, while the two smaller trees to the right (circled) are from Wisconsin.

The Ozark area has the greatest diversity of tree and shrub species in Missouri and can be used to grow trees for wildlife and commercial forest products, but the soils are often thin and rocky with varying fertility levels. Desirable species typically found on the better sites include scarlet, northern red, Shumard, black and white oak. In the eastern Ozarks, cherrybark oak, sweetgum and tulip poplar are common. Shrub species include flowering dogwood, aromatic wetter ground, common species include cottonwood, silver maple, hackberry, sycamore and green ash. On higher ground: pecan, pin oak, black walnut, swamp white oak, northern red oak, and persimmon.

The Southeast Lowlands area has deep river deposited soil and Crowleys Ridge, a very hilly area of deep, rich soils. Nearly all of this area was once forested. Species include baldcypress, hackberry, cottonwood, silver maple, sycamore, pin oak, willow oak, overcup oak, sweetgum, and green ash. On higher ground: tulip poplar, white ash, American beech and a variety of hickory species are common.

The soils and climate conditions of Northern and Western Prairie areas are not as favorable to tree growth. Site and species selection are very important, and after-planting care needs special emphasis. Common species in the uplands include bur, white, swamp white, Shumard, black and northern red oaks, among others.