I ordinarily do all my weeding by hand, but i'd like to use Round Up on an area that's gotten particularly challenging. How close to a given tree can i spray Round-up without adversely effecting the tree roots? Should i pretty much do all my weeding within a several foot radius around the trees by hand?
You can spray right up to it. The only time I would worry at all is if it is a small shrub and even then the herbicide is not taken up through bark that well. Roundup is not active in the soil and will not work it's way down to the roots and be taken in.
It also will not kill a tree unless it is sprayed on the very top of the tree. I witnessed low limbs pruned off a large pine tree by simply spraying RU on the end of the limbs to be removed. With in a year, the limbs were shed, the tree still is healthy.
I asked at the feed store about using Roundup. I was told that the agricultural version is hundreds of times stronger than the commercial kind, and that they would need a special license to sell it, so they don't. The store owner said to get the concentrate (at Canadian Tire) and mix it much stronger than the container recommends. Even at that it can take 2 weeks or more before the weeds and grass are dead. Then the dead stuff should either be raked off or tilled under. We haven't done anything yet (still planning) but I think I will throw some compost over the lot and just plant my groundcovers without worrying about the dead stuff. Best not to use it in windy weather if you want to keep your neighbors happy.
Unless you've tried the regular strength and it doesn't work, I would go to full nuclear strength Roundup just yet, personally I think it's always best to use the friendliest thing you can do deal with the situation, otherwise you may end up hurting yourself or causing unintentional damage to something you didn't want to damage. So I'd start with the regular strength stuff and give that a try first.
I have used Ortho Weed Be Gone and that works very well - good part it does not harm grass, or other desirables. I sprayed it directly on a patch of myrtle to kill some thistle - took the thistle out overnight and did not harm the myrtle one bit. I also sprayed it on a Frasier fir to control a vine type of weed that literally grows up the trunk of the evergreen and wraps around it (not sure the variety) I have been battling for 5 years using round up very carefully (a drop or two on each leaf of the vine). With the Ortho, the vine is dying and there is no damage at all to the fir and I sprayed without concern for getting Ortho on the needles. I have not sprayed it near annuals or the vegetable garden because I am affraid it will take them out. I now stay away from roundup because it is non selective at any strength, the weaker the mix only means it will take a little longer to produce results - at least that has been my experience.
if it is growing on an established tree, PULL IT. The good thing about bindweed is if you break it off at the soil level, it dies. The plant doesn't recycle itself from the root. It is easy to kill without chemicals. All you need to do is yank, yank, pull, and tug.
I think it would be a lot quicker and less time consuming for you. There is no sense using chemicals if you don't need to. I sell all of these chemicals at work. I would not make you waste your money in this situation. Faster and more effective to yank.
You can go to professional outdoor equipment company and buy a product called Razor Edge.
Exact ingredients as the round up. It's a concentrate. About 30% cheaper.
2.5 gallons is about $115.00. Works really well.