Not long ago, wrote in one of her gardening newsletters about using boiling water to kill small weeds. I tried her suggestion on the weeds that sprout up in the bricks of my paver path and it works great! Easy and no chemicals - just the suggestion I was looking for.
I do have a question about this method, though. Can I use small amounts of boiling water to kill weeds under a tree without hurting the tree? It just seems like the water might damage the tree's roots (the tree in question is our beautiful Mountain Ash and I would never want to hurt it).
If boiling water is out of the question under the tree, would smothering the weeds with newspaper and a layer of mulch hurt the tree? Or do I just need to resign myself to digging out those darn weeds by hand?
Boiling Water to Kill Weeds
2 replies to this topic
Posted 10 July 2006 - 08:10 PM
I think the smother method is your best option. Since most of a tree's feeder roots are in the top 18" of soil I think the boiling water could cause some damage.
Posted 19 July 2006 - 07:58 PM
I agree. I've never read much about how much heat it takes to kill roots but do know I've read about turf root death. Now that I'm trying to recall the temperature, or find the original reference, I can't come up with the source to be certain. Yet I feel pretty sure it's 90-something. Maple roots right there in that first couple of inches of soil could eaily get that hot, if you were pouring a good deal of boiling water there!