I have planted my 138 evil magma peas in two of my homes (same 138 seeds, at two different times), and both times I did once I got to a certain number of plants planted, any housing items that happened to be left laying around turned into plants!! I now have 138 planted peas, 2 of the fiery boom shrooms I planted as "likes" , and 9 housing items that turned into "fake" plants! They look just like the "real" peas but have the words "evil magma peas" above them. I can't treat them with the spells, can't plow them up, and the original items that they were in the first place do not show up in the attic list. Another oddity about them is, it seems, each of the "fake" peas are somehow tied into one of the real ones and seriously impedes their growth. I mentioned this months ago, but never received any response, and the glitch was never addressed!
I have never had this problem myself, I only have about 60 EMPs. Maybe the system isn't equipped to handle 138 plants somehow? You're right, this needs to be addressed, especially since you appear to have made a real investment in your gameplay (either in time, farming for EMPs, or else buying them outright).