I have Elaeagnus umbellata in my front yard - it has large thorn/spikes that I forget about until pruning. It blooms in early spring though I think..amazing fragrance!! I let the ornamental tobacco reseed beside it...figuring the oxygen balances out
That's also why I allow clover to grow in my potted plants. I'd love to hear folks thoughts on that though as I just started doing that this year.