Would need to know the name of the chemical used or at least what the primary ingredients were in it. If it was used per package directions then the packing should tell you how soon it is safe to plant there. Some dissipate rather quickly while others can remain in the soil for years and root crops would be the most likely affected. This, of course, is in addition to any of the oleander's glycosides which may remain in the soil I don't know if specific testing is available for glycosides but it would be worth checking into. You might want to post over on the Soil Forum here for additional input but without the name of the chemical used it will be hard to say one way or another. Personally, I would use the area for a flower bed rather than as a food plot and grow the food crop somewhere else. If the flowers don't survive in the area then you will know that there is residue from the root killer still there. JMO Dave

That is English ivy and it can also cause a rash on some people.

It is very possible that your cedar (Juniperus virginiana) has allelopathic properties. However, even if it didn't, that does not sound like a very suitable location for your tree. At least not how I'm picturing it in my mind. Woody plants, by the way, do much better in the long run if the soil is not amended with compost or anything else. Planting into the plain native soil is best.

Mike, that is just beautiful! Our rocks are natural decomposing granite boulders. Some as big as a house. We name them! One is house rock. That's how we describe which plant is where. You know, the Fig on the east side of house rock? I wish we knew the planting zone of the original poster. We have very well drained soil here along with very steep slopes. I have this big hiking stick to help me navigate the hill. We have many fruit trees, a small vineyard, and lots of rosemary and junipers for water retention. We have two big pine groves, one of which has a nice flat area, and one day a weathered old picnic table will go in there. We plan to make a natural fire pit on chimney rock... another one we named. It has boulders on top of a big boulder with pretty easy access. We just need to build a deck so we can enjoy the fire in the natural pit. Also need to put some spark arresting mesh so we don't light our mountain on fire. Neighbors would hate that! Weeds are always a problem. If you are non-organic, roundup works pretty good. You just have to keep at it. Vinegar works also on weeds. Pour boiling hot water near the roots of some. That will kill the roots, but make sure you aren't killing good roots of plants you want. Good luck! Suzi