Tag Archives: invasive

Invasive Balloon Flower Takes Over the Garden

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.

seeds landed on front strip across walkway (blooming with blue flowers)

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.

pulling to reveal tap root

 

Shiso Begone!

 

red shiso in sidewalk crack

red shiso in sidewalk crack

Shiso was banished from my garden this week. In early spring, I obtained a package of shiso seeds, both green and red (Perilla frutescens var. crispa). They were from a reputable company; the package itself was pretty and full of information. Although they were difficult to germinate I had about four small plants, three with red leaves and one with green leaves growing in my bean/cucumber bed by the beginning of June. Similar to coleus, shiso is a warm weather annual used quite a bit in Asian cooking. I was looking forward to learning how to use them, I was already thinking of putting the leaves in a green salad and brewing a shiso tea.
Last night, my daughter and I went for walk and I noticed that a neighbor had quite a lot of red shiso in her front yard, several feet high. Further down, more shiso plants were visible but in cracks in the sidewalk — wherever it could get toehold in some soil. I have never seen such an aggressive edible plant before (except for mint) so I looked up shiso on the internet. Turns out shiso is a cousin of mint but spreads via seeds while mint runs along its stems and sets roots. According to the Virginia Native Plant Society, shiso is on the September 2009 Invasive Alien Plant Species of Virginia list as “occasionally invasive.” According to the National Park Service, “it readily escapes cultivation and has become a problematic invasive plant in natural areas across the mid Atlantic region.” Shiso is toxic to herbivores including cattle and NPS recommends not purchasing or planting shiso. I have battled Korean bellflower (Campanula takesimana) for years and have no wish to repeat that performance so I have no qualms about pulling a few plants. However, I find it fascinating that this invasive quality was never mentioned on the seed packet. Maybe it is not a problem in other areas of this country but if I had not taken that walk, I would have never known shiso’s dark side until it was too late. Most likely, I would have let one of my plants go to seed and would have been pulling shiso out of my garden for years to come, just like the Korean bellflower. Well I’m on to you, shiso, sorry, not my garden.

red shiso buddy buddy with invasive ivy

red shiso buddy buddy with invasive ivy

red shiso along driveway

red shiso along driveway