I am new to this site, so "Hello" to all. I consider myself a novice gardener, so please keep that in mind when I pass along some of the things I have picked up to solve some of the problems in my garden.
To answer your specific questiion, "I still await some solid info on the dissipation time of ammonia." , I did a Google search "amonia to nitrate' and came up with this link:
http://en.wikipedia.org/wiki/N...
I will readily admit much of it is over my head.
I can confirm that my own research shows that Round-up must be used in the active growing period of the plant to be effective. (For some plants that is a very small window.)
I am battling poison oak. It's a war I intend to win as I am very sensitive to poison oak ... think docs and hospital visits.
I, too, am very reluctant to use chemicals in the garden as my town is located in the midst of a forest.
My most successful methodology is to use concentrated Roundup, alcohol, weed barrier, and black plastic.
Since PO is often spread by bird drops, I don't bother spraying the plant. I cover the plant with a garbage bag for disposal and then I cut it as low as I can. Since PO emits a sap as soon as it is cut, I swab the trunk/stump with the alcohol and then apply the Roundup. I put the weed barrier around the base of the plant with the stump sticking out and weigt it down with rocks so that it won't move. I then place a rag soaked with Roundup over the stump and cover the whole thing with heavy black plastic. I make sure the black plastic is weighted down, too, so that nothing will move it away from the plant I am killing. Since my summer temps are usually in the high 90s and low 100s for months, the remaining stump gets thoroughly cooked.
So far, I have never had to go back and treat a PO plant to kill it ... just to remove the unsightly plastic and weed barrier. PO sends out runner roots underground, but this method seems to get to them and I have never had new plants come up from a plant I have treated, nor have I had to go back a re-treat a plant.
I hope this helps. I honestly don't know if this method will work with ivy, but it sure works on poison oak.
Smiles,
Lyn
