Cornell Cooperative Extension
Southwest New York Dairy, Livestock & Field Crops Program
Tall waterhemp is one of the most problematic weed species throughout the Midwest and has now arrived and spread to eight counties in Upstate New York. Waterhemp can spread from field-to-field and farm-to-farm on equipment, clothing, application equipment, or via water from over flooded ditches and rivers. Following a recent field day event we wanted to demonstrate the amount of weed seed that could travel back with you.
Boots that were considered “clean” were not as clean as we had thought (Figure 1). A knife was used to clean the boots and break up any hard clots that were present. Once the boots were clean, tweezers were used to separate the weed seeds from the dirt (Figure 2). We then separated out the pigweed/waterhemp seed from other weed seeds that were present and pigweed seeds were counted (Figure 3). We also double checked the dirt and found one pigweed seed stuck to a clay particle (Figure 4). Math was then conducted to estimate a 3 year establishment of waterhemp assuming 50% of the seeds were waterhemp and 100% were waterhemp, respectively.
The math is seen below:
16 pigweed seeds + 1 pigweed seed hiding in soil = 17 pigweed seeds from 2 boots.
Assuming only half of those are waterhemp and it can produce 250,000 seeds per female plant: 17/2 = 8.5 X 250,000 = 2.125 million seeds the following year in a field.
Assuming every seed on the bottom of the boots are waterhemp: 17 X 250,000 = 4.250 million seeds the following year.
Assuming 75% survival rate and reproduction in year 2: 4.250 million X 75% = 3.1875 million plants X 250,000 seeds per plant =
**796,875,000,000 seeds going into the soil in year 3 (potentially)
In conclusion, correct and early identification is very important; learn the correct features. Proper cleaning and sanitation of equipment, clothing, and vehicles can help prevent spreading. Intense management and continuous scouting are vital to eradication of this weed species. Mechanical control such as plowing can bury the seed deep which might decrease seed bank numbers.
There is a phrase, “an ounce of prevention is worth a pound of cure”. This phrase rings especially true in preventing the introduction and spread of invasive species in our national parks. There are a variety of simple steps a visitor can take to ensure that they are not transporting invasive species into, around, or out of a park. Find out how you can help stop the spread before you recreate, afterwards, and even at home!
Cleaning your boots before you head out on the trail can help prevent the spread of invasive species.
Before You Recreate
Check in with your park. Visit your park’s website or check in at the visitor center to learn about current issues with invasive species.
Bring short gaiters. Wearing short gaiters to cover your socks and pant bottoms can prevent sticky seeds, such as cheat grass, from getting stuck in your socks.
Clean your shoes or boots before you hit the trail. Use boot brushing stations when provided and consider carrying a boot brush in your car or pack. Rinse the soles if possible. Learn why you should brush your boots before heading out.
Don’t pack a pest. People from all over the world visit national parks. If you’re traveling by land, air, or sea make sure you Don’t Pack a Pest that could be lingering on certain types of food, plants, or other agricultural items.
Use weed free feed, if possible, when using pack animals, such as horses, mules, and cattle, prior to and during, your visit. Contact the park you will be visiting to see if they have a list of local vendors of weed seed free feed.
Don’t move firewood. If you’re building a campfire, use local firewood. Do not bring in firewood from outside the immediate area. (Check park websites for specific instructions).
After You Recreate
Play, Clean, Go
Wash your vehicle, especially if you have been driving on unpaved roads or off road. Plant materials can get stuck in your tires and undercarriage. This includes cars, bikes, and ATV’s.
Shake out your tent, camp chairs, sleeping bags, and other camp accessories before leaving the campsite to remove any plant or seed materials.
Brush off or wash your pets, if they have been out romping in the parks. Sticky seeds can hitchhike on their fur.
Clean your shoes or boots by knocking dirt and plant materials out of the treads. Consider carrying a boot brush in your car or pack. Rinse the soles if possible.
Clean, Drain, Dry. Thoroughly rinse your gear and pressure wash your boats, water skis, and other recreation vehicles on site. Plants and aquatic organisms can get into any place water can get into. Use hot water if available. Learn how to clean, drain, and dry.
Don’t dump your bait. Unused bait should be discarded into trash cans. Using live bait should be avoided if possible. Many parks do not allow live fish or amphibians as bait. Make sure to know the regulations of the area you’re visiting.
Report invasive species. Locating invasive species just as they are beginning to invade an area and treating new infestations quickly is a management approach called Early Detection Rapid Response (EDRR). In a national park, let a ranger know when you spot invasive species. They will want to know the location (GPS coordinates if possible), the name of the invasive species, when you saw it, and photos of the species. Outside of a national park, follow these best practices for reporting.
Regional planting guides can help you find the best plants for your garden.
Don’t let it loose! Do no further harm by not releasing your pets into the wild or dumping aquariums into waterways.
Choose native plants. Replace any non-native plants in your garden or landscaping with native plants. Check in with the staff at your local plant nursery or native plant society for help choosing plants native to your area. Help pollinators while you’re at it with these pollinator planting guides.
Identify and remove invasive plants from your home. Every little bit helps! Use these regional or state lists to help you get to know the invasive species in your area.
Buy local. Help reduce the possibility of spreading pests on the food that you buy by choosing to buy local produce. It will also help fight climate change!