Weeds & Fire

Cost Share Program
After a wildfire or other major soil disturbance, noxious weeds are often one of the first plant species you will find. These aggressive weeds use this opportunity to gain a foothold on the newly disturbed ground. After a wildfire it is important to survey your property and look for and treat these noxious weeds. A combination of control methods such as herbicides, re-seeding and the use of biological agents, makes for a well rounded Integrated Weed Management Program.

Please contact the Land Operations/Range program if you are interested in having a free onsite weed consultation to learn what invasive weed species are growing on your property and what control methods would work best for you. 

Status on weeds in the burned areas:
Land Operations staff were busy last fall and this winter seeking and applying for funds to help battle invasive plant species in the recently burned areas.

The primary goals of weed control in the burned area is to keep weeds from spreading from road shoulders into the recently disturbed soil, keep “new invader” species from gaining a foothold in the burned area and to keep previously known weed infestations from spreading.

Currently funds are primarily from BAR (Burned Area Rehabilitation), to treat invasive species along roadsides within and around the Buffalo Lake fire, St. Mary’s Mission Fire, Silver Creek Fire, Devil’s Elbow, 21 Mile Grade Fire and our more recent fires Tunk Block and North Star.

Biological control releases (insects that feed on specific weed species) include insects to control; Canada thistle, common St. Johnswort, Dalmatian toadflax, diffuse and spotted knapweed. Field tests indicate that some species of biological controls did not survive the intense blaze of last year’s wildfire. Therefore releasing biological controls into these expanding weed populations is a very important step in controlling invasive weed species.

Noxious weed management after wildfires
One of the most significant economic impacts post-wildfire is the increase in invasive and aggressive weed species. Many native plants will thrive post-fire, but unfortunately so do weeds. These destructive weed species compete with desired native species for space and nutrients, as well as eliminating wild-life/livestock forage, increasing risks of wildfire and removing wildlife habitat.

Keep in mind that in addition to spreading by seed, some weed species can regenerate from roots and root fragments. For example; leafy spurge roots can penetrate up to 26 feet deep in the soil, once the vegetative material on the top of the soil burns, the roots are stimulated to produce more plant material. Typically most severe fires will only damage roots to a few inches below the soil, therefore noxious weeds, with their very deep root systems have an excellent chance of surviving.

So what can you do to help keep weeds from invading?

  • Set up a weed monitoring program for your property. Take quick action on weed control, particularly when you see a species that has not been there before.
  • Pay close attention to areas of your property that were severely burned or had a prior history of noxious weeds, these areas will need the most attention for weed control. Dependent upon the weed species, seeding in these areas might be an excellent first step in controlling the weeds.

Re-vegetation considerations:

  • Use species adapted to the conditions on site.
  • If the ash layer is absent, prepare the seedbed by lightly scarifying the soil.
  • Add nitrogen fixing legumes to improve soil structure and ensure long-term re-vegetation success.
  • Control noxious weeds prior to seeding.
  • Use weed free hay/mulch to protect soil and seeds from erosion.

If you need any assistance in controlling noxious weeds, identifying weeds on your property or help coming up with a weed management plan, please call our office at (509) 634-2338