When Weeds Take Over
When Weeds Take Over by Neil Dougherty
As a professional wildlife consultant, I know all too well the impact dry conditions can have on wildlife food plots. I
spent most of the summer of 2005, like most land managers, watching the ten day future weather forecast
hoping for cooler temperature and just a little steady rain. Every day that passed without rain put more pressure
on my food plots and gave some of the more persistent weeds a chance to thrive. If your food plots were weedy
last year you’re not alone but now its time to decide what to do when weeds take over.
The first step in dealing with a weedy food plot is to determine why the food plot lost the battle with weeds in the
first place. Get to the root of the problem, so to speak. Most weed infestations in food plots can be tracked back
to a shortcut taken during the original planting process. For example, a food plot will often be overtaken if the
soil has not been properly amended.
That’s right, if your soil pH value is too low or you decided to skip applying fertilizer this year you are giving
weeds a huge advantage over the preferred plants in your field. Let’s take for example a food plot that was
planted on a neighbor’s property near my research facility in southern New York. The food plot was planted in
an old abandoned hay field. The land manager planted a perennial clover mix in a food plot with a soil pH value
of 5.6. Rather than apply granular lime to fix the low soil pH, he decided to try a quick fix and boost the fertilizer
rate. Right off the bat the clover mix was in trouble. The low soil pH made it difficult for the plants to absorb
nutrients in the soil and resulted in plants that were growing at 45% of their potential. Slow growing clover plants
opened the door for weed infestation. In this food plots case, the weed that infested the plot was Ragweed.
Ragweed unlike the clover blend can absorb nutrients just fine when the soil pH is in the low to mid 5’s. In the
end it wasn’t even a fair fight, the ragweed dominated the plot by absorbing the limited amount of moisture in the
soil and the plot had to be replanted. If you have been working hard on amending your soil and your food plots
still are weedy there are other factors that could be at work.
One of the things I run into quite a bit while trouble shooting weedy food plots, is an unnecessary loss of soil
moisture during the planting process. I can’t stress enough the importance of managing soil moisture loss within
new food plots. There are two very effective ways to manage soil moisture loss. The first technique to conserve
soil moisture is to use trees along your plot to block sunlight from reaching the ground and drying the soil.
If you are planting in a part of the country where hot dry conditions are often encountered during the summer
growing season, hide your food plot from direct afternoon sunlight. For most of us, the hottest time of the day
during the summer months is between 4-6pm. The next time you are in your favorite food plot pull out your
compass and look in a southwest direction. That’s where tall trees should be located blocking direct afternoon
sunlight from reaching the food plot.
Remember, in the afternoon air temperature has risen and long since burned off the dew. Hot afternoons and
direct sunlight will send the soil temperature soaring in fields. High soil temperatures increase the rate of soil
moisture loss and give weeds an advantage over preferred food plot plants. Remember, my neighbors plot with
the ragweed infestation? His plots also had direct afternoon sunlight and high soil temperatures. Combined hot
dry soil with low soil pH and an increased rate of fertilizer and his ragweed grew like it was on steroids.
Another technique that can be used to control soil moisture loss within a new food plot is to be sure to pack a
firm seed bed prior to seeding. Using a roller or cultipacker to tighten the seed bed before seeding will not only
allow your seed to germinate more effectively but also faster. A well packed soil will quickly absorb and hold
rainfall allowing for a better stand establishment in a shorter period of time. More importantly, a well packed
seed bed will allow moisture to seep up from deep below the food plot when it’s not raining.
For example, I replanted a food plot in a perennial mix in the spring of 2005 but was running a little late and
decided to cut a corner and only cultipack the field once prior to seeding. After I planted the field we had
sporadic rainfall for the next forty-five days. The field looked horrible, only about thirty percent of the seed had
germinated. I pushed a soil probe into the soil and found moist soil about three inches below the surface crust.
Moisture was trying to seep to the surface from deep below the plot but the loose soil allowed the moisture to
evaporate before it reached the seeds located on the surface of the soil. It was then I knew I had been caught
taking a short cut. To fix the problem I cultipacked the failing food plot stand again. Almost immediately seeds
started to germinate, soil moisture was seeping from deep within the plot to the surface allowing for faster
germination.
Another common factor that contributes to weed infestation is improper care of existing fields. If you have an
established stand of Imperial Whitetail Clover or another Whitetail Institute perennial you should be at the very
least mechanically controlling weeds by mowing grasses and weeds before they get a chance to reseed
themselves within the food plot. In addition to mowing plots, chemicals can easily be used to kill grasses or
broad leafed weeds within the plot but sometimes despite technically sound planting practices, effective mowing
and grass control techniques, food plots just wear out and become weedy. Chalk it up to Mother Nature not
cooperating but some times weeds just take over.
If weeds have taken over your plot you have two obvious choices, kill and replant or chemically treat the plot to
remove the problem plants. As a wildlife consultant my first choice when I encounter a weedy field is to save the
field without replanting. That means I will use chemicals when possible to clean up the plot. The type of
chemicals and rate of application will depend on the type of food plot you intend on treating.
The first step is to identify the type of weed you wish to control. There are lots of recourses available to land
managers to help them identify weeds and grasses. Your first choice may be a local soil conservation extension
agent or online resources like the Weed Science Society of America (www.wssa.net). The folks at Whitetail
Institute have a great track record for helping customers identify weeds by simply calling their help line. Once
the problem plants have been identified it’s time to select the type of herbicide to spray over the food plot.
Selecting the right type of herbicide can be a little tricky as some types of herbicides may kill your preferred
plants in your food plots as well as the weeds you wanted to control. There are a few rules of thumb that will help
you select the right herbicide for your food plot.
Most broadleaf blends of seed can be sprayed with a grass specific herbicide. That means grasses will die but
not the preferred food plot plants. For example, you can control grasses in Imperial Whitetail Clover and all
Whitetail Institute perennials with a grass-specific herbicide labeled for use on food plots. The forages will not be
affected by the herbicide. The folks at Whitetail Institute again revolutionized the food plot business when they
introduced herbicides that were specifically designed to be sprayed over their blends. Arrest is the first ever
herbicide sold in affordable quantities designed to kill grasses within food plots. Grasses can effectively be
wiped out in Imperial Whitetail Clover, Alfa-Rack and Chicory Plus stands. Grasses are not the only type of
weeds that can be killed with the proper type of herbicide. Most types of broadleaf weeds can also be eliminated
within Imperial Whitetail Clover stands by applying an innovative broadleaf weed killer called Slay. If you have
questions on determining the type of herbicide to use on your weedy food plots contact an expert consultant at
Whitetail Institute by calling 800-688-3030.
If you have been planting food plots, chances are you have been struggling with controlling weeds and grasses
within your fields. My first suggestion is to first back up and try and find out what went wrong within the plot. Be
sure not to repeat the same mistake that caused the original weed infestation then solve the problem. The good
news, there are products on the market that can dramatically increase the life of your food plot and can clean up
when weeds take over.
"Reprinted with permission of the Whitetail Institute of North America.
For more info on this article and other related topics contact them at
(800) 688-3030 or visit their website at wwww.whitetailinstitute.com."