"There's a nice bright yellow flower in bloom in front of the bed that has the new rose bush," my husband told me after an early morning round of watering. This report had me puzzled, because while there were new plantings in that area, they were all in the range of blues to pair with the deep pink rose bush. Yellow wasn't in the color scheme that I'd remembered planting, so I wandered out after breakfast to take a look. Aha. Looks like squash to me. Definitely didn't plant it, and it's a veggie surrounded by perennials, but I might let it grow and see what comes of it.

I like happy accidents, like the coral bell that's volunteered in the planters where I grow basil. As it happens, I've been feeling the need of another colorfully leafed shade dweller, so I'll plunk it in its new home. And the prolific Blondkopfchen heirloom cherry tomato I planted years ago has been keeping me well supplied with bounty, all courtesy of self-sowing.

Not all volunteers are quite so welcome, of course, like the weeds, and some variegated artemesia that grows like weeds. But the sporadic mallows that pop up at random sometimes fill the bill, filling in a gap with their pink profusion of blooms that bob in the breeze. And if they grow someplace I don't want them, they're easy enough to pull.

My favorite volunteer has been a clematis plant that so far has generated two others. Hard to go wrong for the price of digging it out of the lawn.

What's your favorite volunteer? Or least favorite, for that matter. We've all got a few of those that have to be shooed away.