Siebold’s Magnolia…Defeated or De-Heated?

Back in 2018, I spotted a listing for Korean germplasm of Magnolia sieboldii on the seed exchange list for the International Magnolia Society. For those who don’t know magnolia species, Magnolia sieboldii is considered one of the most beautiful in the genus, but it’s widely known not to grow in hot, humid climates. I had actually seen this pendant-flowering species on Korea’s Mt. Sorak in 1997, but didn’t gather seed because I assumed it ungrowable. Subsequent to that trip, we would try in our garden, but we stopped after killing it on our requisite three attempts. Good sense would tell us to stop trying, but that’s not something we seem gifted with.

As with all plant breeding and selection, it’s a numbers game. If the desirable trait exists in the species, you’ll eventually find it, if you grow enough seedlings. Since there were plenty of seed available from the exchange, I reasoned that if we grew enough, perhaps one would show some heat tolerance.

I don’t remember exactly how many pounds of seed arrived, but they were promptly sown, and germination soon followed. Each time the seedlings were transplanted, only the most vigorous ones were selected. These were then grown in our research cold frame for the next year, subjected to full sun and through a typical NC summer. By the following spring, we had whittled down our selections to nine clones that had thrived in containers, and in early spring 2019, they were planted in the ground. Over the ensuing years, four passed away, leaving five. This spring, four years after planting, two clones have topped 7′ in height and are flowering beautifully, as you can see below.

There are less than 20 named selections of Magnolia sieboldii, most selected either for double flowers or blush pink tips, but none for heat/humidity tolerance. The next step will be to make a final selection which we’ll name Magnolia sieboldii ‘Southern Pearls’. Scion wood will then be shared with Magnolia grafters who will assist with our mission to propagate and share. Winter hardiness of this clone should be at least Zone 5b – 7b.

Magnolia sieboldii ‘Southern Pearls’

Korean Celery

I first grew Korean celery for years for the flowers, never realizing it was an edible food crop…a first class edimental! I have a fascination for plants in the Apiaceae family, whose members include Angelica, Queen Anne’s Lace (Daucus), carrots (Daucus), celery (Apium), parsley (Petroselenium), etc. Not only are many of the family members attractive in flower, but they are supremely attractive to pollinators, especially wasps.

Not all of my Apiaceae experiments have turned out well. More often than not, members of the family are short-lived (monocarpic or biennial), while other are prolific seeders. One which has far exceeded my expectations is the Korean native, Dystaenia takesimana.

Dystaenia takesimana is an endangered native to Ulleung Island, where it’s known by the local name, Soembadi. Most likely, dystaenia is endangered because it was also used to feed livestock (pigs). Humans eat Korean celery mostly in late winter, when it can be eaten raw like celery, or boiled, tasting quite like spinach.

This amazing evergreen perennial puts on a show with 5′ tall stalks of white umbels, starting for us in early June. When flowering is complete, the stalks die back as the new basal foliage emerges. Unlike many members of the family, the attractive cutleaf basal foliage remains evergreen all winter. You’ll see this popping up soon in an upcoming Plant Delights catalog. We hope you enjoy this as much as we have.

Dystaenia takesimana
Dystaenia takesimana

Mukdenia – a Rocky Sax

Mukdenia is an odd monotypic genus in the widespread Saxifrage family, along with cousins heuchera, tiarella, and the namesake saxifraga. The odd genus name honors the former city of Mukden in Manchuria, which is now known as Shenyang. Mukden was the site of the largest modern day battle, prior to WWI. In case you missed it, the final score was Japan 1, Russia 0.

Several on-line sites, including that purveyor of accuracy, Wikipedia, proclaims there to be two species of Mukdenia, which is sadly incorrect. Although I’m sure Mukdenia rossii would like a sibling, one simply does not exist. I think of Mukdenia like Smucker’s…with a name like that, it has to be good…and it is.

Mukdenia naturally resides in China and Korea, where it can be found in some rather inhospitable places. I had to laugh when I read countless on-line articles that repeat the myth that mukdenia needs water during summer drought. It certainly doesn’t mind summer water, and will probably look better as a garden specimen with some irrigation. My first encounter with mukdenia in the wild was in fall 1997 on South Korea’s Mt. Sorak, where it thrived, growing in the rock cracks of a nearly vertical cliff (below)

Mukdenia in situ, Mt. Sorak, Korea

When we built our concrete crevice garden, mukdenia was one of the first plants I wanted to plant to see if it would mimic what I had seen in the wild. Below is our 2017 planting of Mukdenia rossii ‘Karasuba’ in late March/early April 2022, as it emerges in flower. The foliage continues to expand around the flowers. Our plants get 3-4 hours of sun each morning, then shade the remainder of the day. Winter hardiness is Zone 4a-7b.

Mukdenia rossii ‘Karasuba’ in crevice garden – late March
Mukdenia rossii ‘Karasuba’ in crevice garden – early April