wrote:

So if I win my current battle with two 25ft poison ivy bushes
(currently going at them with Roundup and triclopyr in various forms
of application), what should I plant in their place to minimize the
chances that any new seedlings will have the opportunity to sprout and
thrive? Any ground cover that is a decent competitor to poison ivy?

One never has to attack any more than a 2' poison ivy plant. It is easy
to cut the rest off. You don't need to remove it. Just sever it from
the part of the plant with roots. I have had poison ivy vines grow to
the tops of tall trees, but I just remove a section of stem about knee
high and spray the bush that is left. Sprays that kill the roots like
roundup work the best. Sprays that kill the tops but not the roots are
the least effective. They recommend cutting it off at the ground and
spraying each flush of growth that comes back until it is exhausted. It
is stoloniferous so you may actually be poisoning plants many yards
away. I used to pull it out by the roots, but the stolons would extend
10 to 20 feet.

They come back from birds eating the white berries and adding fertilizer
to the seeds and dropping them all over. If the seeds never hit the
ground they never grow, so a bushy plant will keep the seeds from
reaching the ground and germinating. Also, if there is nothing for
birds to sit on, they seldom deposit the fertilized seeds. What will
bring back lots of poison ivy is a planting especially for birds with
lots of plants with berries and seed.
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