Today I tweeted that it would be good to pull weeds since it had rained buckets for the past few days, thus decreasing the heat and humidity and loosening the soil. For me, the time was ripe to pull an invasive plant from my garden, balloon flower (Platycodon grandiflorus). “Balloon flowers?” you say, “but it has such pretty blue flowers and the kids love to pop those inflated buds.” Yes, my kids did like to pop the buds on my original plants as they walked to the front door and yes, they do produce pretty blue flowers on tall stems all summer long. But after 10 years, the kids don’t see them anymore (because their heads are always bent down viewing their iPhones) and the original four have multiplied into hundreds, crowding out my other perennials in my Virginia garden.

original four plants have multiplied on left side of walkway and have tan seed pods (directly across walkway is one balloon flower from front garden bed)
Part of problem is that balloon flowers self-seed very fast. The plants could be deadheaded to prevent self-seeding but this is a nerve racking, time consuming task. Each single seed pod has to be clipped off in order to leave the remaining buds or open blossoms. It is not possible to whack the entire plants down a foot. And part of the problem is that they are deer-resistant, drought-resistant, and generally pest free but the worst part is that balloon flowers have long, large tap roots. Breaking off the stem just encourages more stems to grow from the root. Although it is easier to pull and dig after it rains, I still spent hours pulling and digging to get the whole roots out as much as I could. I suspect I did not dig deep enough though, there probably are pieces in the soil that will rise again like the phoenix.
Interestingly, I have found little reference to its invasive attribute on the internet. I did learn that the Kitazawa Seed Company catalog sells them and according to their description, the root, called doraji, is used in Korean cuisine. It is also used as an anti-inflammatory to treat colds and is considered a cheap ginseng substitute. The root can be dried and packaged for sale in Asian markets.
Unless you want to grow your own doraji for medicinal or culinary reasons, don’t plant this invasive perennial in your garden no matter how much fun you have popping the balloons.