Don't Gamble With Saltcedar
by Roger Sheley, Range Weed Specialist
Saltcedar, also known as tamarisk, is an aggressive noxious weed that was introduced to North America from the Middle East in the 1800's. It is a large shrub or small tree that was originally planted for windbreaks, erosion control, and ornamental purposes. By 1850, saltcedar escaped from cultivation and launched its invasion over river systems. Today, saltcedar occurs throughout the United States and currently has been recorded from 16 Montana counties (Big Horn, Carbon, Choteau, Custer, Dawson, Garfield, Lake, Mccone, Missoula, Musselshell, Powder River, Prairie, Rosebud, Sweet Grass, Treasure, and Yellowstone).
Saltcedar has been designated as one of the 10 worst noxious weeds in the United States. This water-hungry weed uses far more water than the displaced native vegetation. Dense stands of saltcedar have the potential to use over 9 acre-feet of water for every acre of infestation. This translates to 14,520 cubic yards of water per acre of infested land. With this level of water uptake, water flow is greatly reduced or, in some cases, eliminated. In heavily infested areas, saltcedar creates flooding hazards by congesting river channels.
Saltcedar has slender branches covered with small scale-like leaves, producing small white or pink flowers throughout the spring and summer. Its important to identify and subsequently report and control saltcedar when detected. This weed is very aggressive and displaces most types of native vegetation such as cottonwoods, willows, and many species of grasses, forbs, and shrubs. This, in turn, greatly diminishes the richness and diversity of wildlife. Once saltcedar has invaded an area, it prevents native vegetation from reestablishing by exuding salts from its leaves, increasing the salinity of the surrounding soil. Wildfires are frequent in saltcedar thickets, but the weed usually survives and regrows faster than the native vegetation.
The best method for controlling saltcedar is incorporating an integrated weed management program. The most successful method involves root plowing 12 - 18 inches below the soil surface to ensure cutting below the root crown. If root crowns are allowed to remain, regrowth is vigorous, reaching a height of 9 feet or more in one season. Its been found that root plowing is most effective when performed during hot, dry weather. To prevent resprouting, the debris generated by root plowing should be thoroughly burnt. Any regrowth should then be controlled with repeated herbicide applications. The herbicides Dicamba, 2,4-D, Tebuthiuron, and Imazapyr are effective, but only when used with another mechanical control method such as mowing, burning, cutting, or preferably, root plowing. Modified root plows that inject herbicides below the soil surface are effective and do not injure cover grasses and other shallow rooting plants. When controlling mature saltcedar, herbicides alone are ineffective. Conversely, herbicide application on young, tender, new saltcedar growth is highly effective. Since saltcedar generally grows in wet areas, caution should be used when applying herbicides to avoid contaminating ground and/or surface water.
Once an area has been cleared of saltcedar, reinvasion must be prevented through repeated applications of herbicide on new saltcedar growth and through revegetation with beneficial plants. The establishment of beneficial vegetation will help exclude saltcedar seedlings from reestablishing while enhancing the ecosystem.
If you notice saltcedar invading an area or if you need additional information, contact your local County Extension Agent or Weed District Supervisor.
