bkenobi
Silver Member
I've been using Roundup in a 4 gallon backpack sprayer for years and it has done ok at controlling the weeks but I never have truly weed free gravel. Last year I didn't spray as an experiment and it's not all that much different (either now or during the growing season) than it would have been otherwise. I got a 15 gallon sprayer I plan to use this year, but I'm trying to decide what to use in it.
I can use the Glyphosate as is (typically 8oz/4gal) but that seems to just kill the weeds that are there on the day I spray within 2 weeks. But, by that time, the new weeds have started to get big enough that it doesn't look much different. By summer, they are all dried up anyway so I'm not sure it matters. It's too wet in winter even if I wanted to try to knock them down. I was recommended last year to add Imazapyr to the tank but I can't seem to find it on it's own so would have to buy a concentrate that already has Glyphosate to try it (kinda silly when I have 2 gallons left...a few years supply). If I can find a quart of straight Imazapyr, what rate should I apply? Seems like 0.05% is a common solution. Also, is surfactant required to get best benefits?
If I do get Imazapyr, is there any risk of using that tank later in other areas (mulch near plants I don't want dead)? I haven't used the 15 gallon yet and am a little nervous about getting it clean since the 4 gallon takes several full tanks to rinse.
I can use the Glyphosate as is (typically 8oz/4gal) but that seems to just kill the weeds that are there on the day I spray within 2 weeks. But, by that time, the new weeds have started to get big enough that it doesn't look much different. By summer, they are all dried up anyway so I'm not sure it matters. It's too wet in winter even if I wanted to try to knock them down. I was recommended last year to add Imazapyr to the tank but I can't seem to find it on it's own so would have to buy a concentrate that already has Glyphosate to try it (kinda silly when I have 2 gallons left...a few years supply). If I can find a quart of straight Imazapyr, what rate should I apply? Seems like 0.05% is a common solution. Also, is surfactant required to get best benefits?
If I do get Imazapyr, is there any risk of using that tank later in other areas (mulch near plants I don't want dead)? I haven't used the 15 gallon yet and am a little nervous about getting it clean since the 4 gallon takes several full tanks to rinse.