Weed Alert! Beefsteak Plant / Perilla frutescens

Perilla frutescens is a pretty weed, but apparently here in Tennessee, it's pretty toxic to cattle and other grazers. FYI, the shrub in the background is Viburnum dentatum 'Pearl Bleu'. The herbaceous plants covering the ground are mostly native columbine (Aquilegia canadensis).

Since I don't put mulch heavily or put down any weed-suppressing chemicals, I tend to have a lot of plants pop up in my garden beds.

Some of them are the usual weedy scourges (crabgrass, spurge, clover, oxalis, etc.), but sometimes there are plants I don't recognize and have never seen before.

Sometimes, these unknown seedlings can be exciting volunteers -- like my discovery of a Sassafras albidum seedling this summer! And I'm pretty sure that my Viburnum dentatum (arrowwood) shrubs have produced a seedling, which I'll try transplanting in the weeks ahead.

But then there are discoveries that initially seem exciting, but ultimately turn to disappointment.

Such is the case with the plant shown above. I thought it might be one of the Scutellaria (skullcap) native wildflowers. I've only seen photos of those plants online, so I wasn't sure what would look like in person.

Anyway, I had my doubts (the flowers from the Scutellaria photos looked much bigger than the blooms on my mystery plant), so I checked with an extremely helpful local expert (Amy Dismukes, UT/TSU Williamson County Extension Agent) and she identified the seedling as Perilla frutescens (beefsteak plant).

Now Perilla is native to Asia and unfortunately, it turns out that it is invasive in parts of the U.S., including Tennessee (according to the National Park Service).

So I ripped it out.

A closer look at Perilla frutescens (beefsteak plant, shiso) before it met an untimely demise at my hands

Could I have eaten it? I'm not sure. In parts of Eastern Asia (e.g., Japan, Korea, China and Vietnam), I believe that Perilla frutescens is used as an herb/seasoning. I'm pretty sure that I've eaten  the occasional shiso leaf (as Perilla is called in Japanese cuisine) as an accompaniment to sashimi or chirashi. It had a very strong, distinctive flavor - not unpleasant, but I can't imagine eating more than a few leaves at a time.

On the other hand, I presume/suspect that I was eating a Perilla cultivar that had been bred for edibility. University of Tennessee says that the plant is highly toxic to cows and horses, and in fact causes more cattle deaths in the state than any other plant.

Meanwhile, a Purdue University paper cites research showing that a chemical compound called a ketone (Perilla ketone, to be specific) may be the culprit as far as the toxicity is concerned. Interestingly, Purdue notes that this ketone was found in P. frutescens samples from Tennessee, but not in seed from Oklahoma plants nor in commercial samples from Japan.

What does this all mean? As I see it, there might be at least a few plausible interpretations of this data:

1) P. frutescens is evolving new chemical defenses here in North America.

2) Perhaps wild P. frutescens has always had chemical defenses, and the cultivated versions grown in East Asia had those defenses bred out of them by humans over a period of hundreds or thousands of years? In that case, perhaps the presence of the ketone in the Tennessee specimens is a reversion to a defense that had been lost? Wikipedia notes that wild North American shiso often has lost the fragrance that makes it a desirable herb and that these wild, weedy plants are not suitable for eating (due to the presence of the Perilla ketone).

3) Perhaps there is great variability in the species (the fact that seeds from wild P. frutescens plants in Oklahoma did not seem to contain this ketone lends credibility to this hypothesis) and it's luck-of-the-draw as to whether a given P. frutescens plant contains Perilla ketone or not.


So, would I personally nibble a wild Perilla frutescens plant growing in Tennessee?

No, I would not.

And since this is a weedy, exotic invasive plant in at least some parts of the U.S., should you (North American readers) come across it growing in your yard, field or garden, I'd encourage you to remove it.

Get more free advice (worth at least what you pay for it!) by subscribing to Garden of Aaron by email. You'll get a quick update whenever I publish a new post. What could be nicer? (A weed-free garden. Yep, that would be nicer...)

Rolling out the Welcome Mat - Aquilegia, Fothergilla, Geraniums, Indian Pink, Salvia and More!

Thanks to my friendly camera-lending neighbor, Christian, I'm able to show you a few more photos from my early May garden - focusing primarily on the flowers you'd see in the front (and side) of the house if you stopped by to visit. This stunning dark purple columbine just showed up this year on the side of my house. I believe it is an interspecies hybrid between Aquilegia canadensis (the red-flowered native, seen in the background here) and one of the Aquilegia vulgaris cultivars that I purchased. Whatever the case, I love it!

The native Aquilegia canadensis went nuts this year - spreading, growing at least 3 feet tall and blooming exuberantly! I thought columbine would need at least partial shade in the Southeast, but these endure afternoon sunshine without any complaints in their northwest exposure. (They do get morning shade.) My only wish - that they would attract hummingbirds. They're supposed to - but I haven't seen any hummers visiting these flowers. (Of course, I've barely seen any hummers at all this year so far.)

Fothergilla gardenii, just looking amazing and acting troublefree - as usual. (That's part of a big patch of Melissa officinalis, lemon balm, crowding the fothergilla from the left side of the photo.)

This Geranium x cantabrigiense 'Biokovo' is only 2-3 years old and it has grown nearly as large as the azalea shrub behind it. After this photo was taken, the center of the geranium splayed open. I'm not sure what happened. I think there's a rabbit living under the azalea bush, so bunny may be to blame. (Perhaps the rabbit excavated a nest and disturbed the geranium roots?) I'll probably try a drastic cutback (which has worked to rejuvenate other geraniums in my garden), but I'm planning to wait until the blooms are done, because (a) they look beautiful and (b) they attract bumblebees!

That same rabbit has been wreaking havoc on the three Indian pink (Spigelia marilandica) plants in the front border. You can see a few stems have been nibbled here.

...and an entire Indian pink has been chomped back here. Darn you, rascally rabbit!

What amazing fuzzy purple-and-white flowers on the Salvia leucantha (Mexican bush sage), a new addition to the Garden of Aaron. Again, these are supposed to attract hummingbirds and butterflies, but I haven't seen either one visiting the flowers yet. Although it's only rated as hardy to zone 8 (and I'm in zone 6b/7a), I found an inexpensive source so I figured I'd take a chance on the plants. Plus, how could you resist these Seussical blooms?

The 'Natchez' mock orange (Philadelphus x virginalis 'Natchez') seems to be doing pretty well during its second full year in the garden. It's sent up some new vigorous, healthy-looking foliage from the base and has some pretty new flowers. The flowers are fragrant, but the scent is quite faint. Perhaps that's why it doesn't seem to attract many pollinators, except for ants like the one shown here in the leftmost flower. (Incidentally, I believe Natchez is a complex hybrid, but it may have 1/4 native ancestry from P. pubescens, which is listed as native to Tennessee, Arkansas and Illinois.)

Close-up pic of the flowers on Penstemon x mexicali 'Red Rocks', another new addition to the garden this year. Red Rocks reportedly has a nice, long bloom season and is supposed to be better than many other penstemons at tolerating humidity and heavy soils.

Lastly, here's a look at the front corner of the house where I planted Panicum virgatum (switchgrass) last spring. I think this is the 'Northwind' cultivar. This is quite a windy, exposed corner on the hilltop and many of the other plants (including a crape myrtle) that I tried here struggled with that wind. Fortunately, the switchgrass does not seem to mind the wind one bit and it's nice watching the leaf blades sway and bend in the breeze. Near the switchgrass, you can see some columbine, self-sown sunflowers, a pink-flowered Salvia greggii and some volunteer Mexican hat plants (Ratibida columnifera).

Thanks for visiting! The garden continues grow and change and bloom and grow more beautiful day by day, week by week. Stay tuned for photographic proof coming soon~! :)

Camellia in Bloom and Aquilegia Returns

A lone camellia bloom and lustrous dark green foliage brightens an otherwise drab February day.

Another blast of cold air (highs in 30s) is approaching this week. I'm not particularly keen on garden work when it's cold and blustery outdoors, so I haven't been doing much in the garden except laying more pine straw mulch.

That said, in the past few days I've ventured out to capture a few highlights from the February garden.

For instance, one of the camellia bushes has started blooming! We have five camellias - three that were here when we moved in and two Camellia sasanqua (Kanjiro and Pink-a-Boo) that I added last autumn. Four of the camellias bloomed back in November and December.

The fifth Camellia teased with big fat buds for the last month or two and finally has started bursting forth with flowers. It is a welcome sight when so much of the rest of the garden is still brown and austere.

It has also been heartening to watch as the aquilegia vulgaris "Winky" puts on new foliage. I have to say that I was pretty impressed with aquilegia this year. The foliage does get tattered (by slugs and leaf miners, I presume?) in the summer, but I cut it back twice last year and each time it produced a fresh flush of foliage.

In autumn, the foliage held green and proud into December.

And when that foliage finally started to fade away gracefully, it has quickly been replaced by new green growth!

Why wait until spring? Aquilegia is ready for new growth now! I went for the 'natural' look this winter and let last year's aquilegia foliage fade away gracefully. You can still see some of it crumpled next to the new foliage. I even think the tans and purples of last year's foliage have their own charm. But if they persist and are still noticeable next month, I may tidy them up a little.

I'm planning to add more aquilegia to the garden in a month or two - both A. vulgaris and A. canadensis. Hopefully both will fare well and I'll be able to share some beautiful photos with you all.

Here's hoping warmer and brighter days are just around the corner :)