I have some I need to clean out. I’m in pennsylvania and have read a fair amount of publications from penn state.
I have a backpack sprayer, round up, bush hog and disc.
I have been considering rhis: I spray it this weekend, mow it next weekend, disc it a few days later…. Then try to get some annuals in the ground before September 1.
I suspect I’ll have residual knotweed next year to treat again so I was assuming annuals would likely be best.
Any suggestions? Do I have a chance to get some useful growth this late in the season? Thanks
the first thing you have done right is waiting until it is flowering. Give the plants a good thorough coat of herbicide and then do not touch the plants this year. You want to let the plant take in, translocate the herbicide around the plant to the root system and process the herbicide. Glyphosate functions by starving the plant to death. So you want it to go on functioning and depleting the energy reserves. If you mow it and disk it you will separate the herbicide from the root fragments. Each one of those little fragments is capable of growing a new plant. Knot weed is extremely good at compartmentalizing off damaged or injured portions of its self.
A back pack hand pump sprayer will do ok. Keep your pressure up as you want a fine consistent coat over the entire plant. Both sides of the leaves and as much of the stems as you can get. If your concentrated glyphosate is 41-50% active ingredient mix it so that what you are putting on the plant is 4-5% solution of the concentrate.
I like to remix in my empty concentrate jugs. They are 2.5 gallons or 10 liters. Absolutely get your self a graduated cup or cylinder for batching chemical. Use 100ml of the concentrated herbicide for each percent you want your mix to be. When you are mixing many many small batches consistency and simplicity are important. Lastly, always keep a journal of what and when you applied something as well as the weather conditions etc etc. You will have successes and failures. It is a lot easier to reduce the failures by being able to look back at your journal.
That knotweed grows thick and fast. It's invading the lawn here, my landlord can't kill it fast enough.
I have had good luck killing saplings and treating cut stumps on species where it doesnt pentrate the bark with the concentrated garlon(19%) in basal oil or diesel fuel.
painting it on each stem sounds pretty tedious when you are looking at treating acres of the stuff.
A high percentage of what I treat is subsidized by the NRCS.
I had heard that dissing would spread it I was just hoping it would be unable once it was sprayed with herbicide.
You guys saved me some disappointment I suspect
Termin8r's Link
First, you want to remove as much energy from the root system as possible. So you cut it down in early June after it has had a large flush of growth. I use a weedeater with a metal circular blade or Oregon mulching blade (the best $30 I've spent!).
Then let it regrow to remove more energy from its root system over the summer. Spray it with glyphosate mixture in August.
90-95% kill rate. You will have to treat a few random plants next year. The key is removing as much energy from its root system so that the glyphosate can kill the roots.
