Released: February 17, 2002

Also see: Early Spring, 2002 Yard 'n Garden news package

K-State Forester Updates Planting Recommendations

MANHATTAN, Kan. – Charlie Barden doesn’t follow the traditional planting recommendations for new shrubs and trees. He’s seen too many crippling or even lethal results for plants – caused both by original "packaging" and by well-meaning homeowners.

"Yes, most plant roots will grow through traditional burlap, and that material eventually will break down in the soil. Today, however, you can’t assume root balls are actually wrapped in what you’d call burlap," explained Barden, who is a Research and Extension forester at Kansas State University.

The greenish burlap showing up in retail plant stores now is an example. The green results from one of the modern treatments designed to slow down or prevent burlap’s decay, he said. In fact, some of today’s root ball wrapping is a plastic fabric that gets brittle when exposed to sunlight, but will NOT decay after planting.

"Even a wide-mesh wire basket can be a problem," Barden warned. "I’ve seen declining 30-year-old trees dug up and found to be slowly falling victim to the original wire reinforcement on their root ball. At first, their roots had easily grown through the wire’s gaps, but tree roots need to grow in diameter, just as branches do. So by cutting through maturing roots, the wire had begun to lay the trees open for decay organisms, termites and a whole host of other troubles."

For large ornamentals, removing a root ball’s entire wrapping may be impossible without special equipment or helpful weightlifter-type neighbors.

"Just be sure to remove everything you can see, once the tree or shrub is in the planting hole. The little bit of burlap and wire left under the root ball shouldn’t cause major problems," the forester said.

Homeowners can cause further woes for new ornamentals, however, if they do either too little or too much to prepare the planting site.

"The hole doesn’t need to be deeper than the height of the root ball. But it should be two to three times the width of the root ball," Barden said. "You need to work the soil removed from that hole, breaking it up into gravel-size pieces.

"Improving that soil with lots of organic material or replacing it with better soil is a mistake, though. Instead of reaching out into the undisturbed soil beyond the planting site, the plant will tend to limit its root growth to where it’s easy. Larger roots may circle around and around the planting hole, choking the tree or shrub as it grows."

Ornamentals that arrive with large roots already circling the root ball will need planting-time help to break that habit, Barden added.

"It may seem brutal, but you need to cut into a pot-bound root ball, slicing about 1 to 2 inches deep down the entire side in three to four places," he said. "New roots will sprout from the cuts, and they’ll all grow outward, into the planting hole soil."

Tamping soil down by stepping or stomping is appropriate only with very sandy soils, Barden added, because it tends to compact other soil types, thus reducing the roots’ long-term air and moisture supplies. Except with heavy clay soils, gently patting soil back in place can increase the risk of buried pockets of root-drying air.

"In general, you should press the soil firmly in place by hand," the forester suggested. "Then when you’re about half done, stop and water the soil in. Finish filling the hole and water again. That should get the job done."

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K-State Research and Extension is a short name for the Kansas State University Agricultural Experiment Station and Cooperative Extension Service, a program designed to generate and distribute useful knowledge for the well-being of Kansans. Supported by county, state, federal and private funds, the program has county Extension offices, experiment fields, area Extension offices and regional research centers statewide. Its headquarters is on the K-State campus, Manhattan.

Story by:
Kathleen Ward, Communications Specialist
kward@oznet.ksu.edu
K-State Research& Extension News