Invasive Roots -- Suggestions?
I'm struggling to prevent invasive roots from strangling my new minis and new regular size roses. In the area I'm forced to use for planting, there are some big tree roots about 18" down and below, coming from the neighbor' yard. These are not the problem, however, because they are deep, and they aren't terribly numerous.
The big problem is the sheer number of roots about the thickness of a pencil and smaller that seem to 'attack' any new rose I plant. I'm not sure what type of roots they are, but the neigbor has several different shrubs and trees such as elms and locusts. After a I dig a hole for a rose, amend the soil, and start watering, the agressive roots from the neighbor's yard rapidly multiply and form a thick carpet of roots over the rose hole and strangle the new plant. I know this from digging up new plants that lasted for a few weeks and mysteriously died. The invasive roots are between 4" and 8" from the surface (not surface roots). Cutting them does no good. They seem to come back twenty-fold.
A few considerations:
1. A raised rose garden is out of the question. I'm trying to establish a row of 6 - 7 roses along a fence and the majority are regular sized.
2. Unfortunately, I can't plant elsewhere in the yard due to shading, structures, and other plants.
3. My neighbors will not kill any of their own shrubs/trees, but they won't protest if I have to cut roots on my side. (Their trees are not right next to our common fence.)
4. Planting mature rose plants with strong root systems may help. The bare roots and the young minis I planted didn't stand a chance.
Today I wondered if jamming an old cookie sheet down into the ground along my fence could stop the root invasion. Is there some kind of underground barrier I could use?
Thanks for your ideas!