YOU NEVER KNOW who you’ll bump into at the public-radio station in tiny Sharon, Connecticut. The latest: Dr. Kim Tripp, a botanist who directed the gardens and science at the New York Botanical Garden when I was editorial director at Martha Stewart. She is an expert in woody plants who, as I did, chose to start over at midlife. We spent time together last week talking exceptional trees for the home garden, and also heard her second-act story—how at age 50 she took student loans and went to medical school, becoming an osteopathic physician who now practices across the street from Robin Hood Radio’s studios, where our conversation on my latest show took place.

Dr. Tripp, the voice of Robin Hood Radio’s newest program, “Your Health,” received her D.O. from the University of New England. In previous incarnations she has her BS and MS from Cornell; her Ph.D. from North Carolina State University, where she also served as Curator of Conifers for the famed J.C. Raulston Arboretum, and did postdoctoral work at the Arnold Arboretum of Harvard University. She knows from trees and shrubs—and that’s what we talked about:

prefer the podcast?

TALK OF GREAT TREES and midlife “do-overs” like mine and Dr. Kim Tripp’s were the topic on the latest edition of the radio show. You can listen anywhere, anytime: Locally, in my Hudson Valley (NY)-Berkshires (MA)-Litchfield Hills (CT) region, “A Way to Garden” airs on Robin Hood Radio’s three stations on Monday at 8:30 AM Eastern, with a rerun at 8:30 Saturdays. It is available free on iTunes, the Stitcher app, or streaming from RobinHoodRadio.com or via its RSS feed. The November 18, 2013 show can be streamed here now. Robin Hood is the smallest NPR station in the nation; our garden show marked the start of its fourth year in March, and is syndicated via PRX.

q&a: great trees for gardens, with kim tripp

Q. What woody plants always got your recommendation—what did you try to encourage clients to plant when you were making gardens for people, while supporting yourself through medical school?

A. The first thing I always did, especially with a new client, was to walk around with them and say, “Let’s just see what’s growing here now–what’s out there and doing well,” and have a look at it and see if we like it or don’t. And we’d go from there.

I found a few plants in our region that no matter what the conditions, were always doing well—even with deer browse.

They were things like Norway spruce—which has had a lot of bad and condescending press, but is actually a fantastic plant.

Other things I’d always see doing well: crabapples, lilacs, and witchhazels—both the fall-blooming native species and the exotic Asian ones, which give us late-winter flowers [such as ‘Jelena,’ above photo]—and deciduous hollies, such as our native Ilex verticillata; red twig dogwoods [that’s Cornus sericea ‘Sunshine,’ with red twigs, white flowers and fruit, and gold foliage, below], and native sugar maples.

With the Norway spruce, I like the pendulous or slightly weepy forms—and they are fast-growing, and resilient, and not expensive. I combine them with red maple and sugar maple in a mixed border to delineate a property border, or create a wind screen, for instance—perhaps to prevent the house from getting blasted on the north side by wind.

Q. Any other tree-sized conifers that you particular like to recommend for the home garden?

A. I love Abies concolor—the white fir from the West.

There are two cultivars: ‘Candicans’ [photo of a sheared one in Margaret’s garden, top of page] which is especially blue, but the one I like the best is called ‘Violacea,’ which is hard to find. It’s the most extraordinary color, if you can lay your hands on the true form of that, which is not easy to do. They’re lovely and reliable, but are not rapid growers. That’s definitely a long-view plant.

Q. You worked at North Carolina State with Dr. J.C. Raulston, and when I visited the arboretum there many years ago, it was the first time I ever saw plum yews, or Cephalotaxus. Tell us about this shrub-sized conifer, which can even grow in some shade.

A. Cephalotaxus are from China, and look like a kind of a yew (which is a different genus, Taxus).  But they have longer needles that are glossy, and are much more tolerant of challenging soils, including heavy clay, than a lot of the more familiar yew.

In our area [the Northeast] we can grow the prostrate one, Cephalotaxus harringtoniana ‘Prostrata’ [above photo in Margaret’s garden], but not the upright or fastigiate cultivars, which get damaged by our winters.

In Cephalotaxus, there are male and female plants—and they can have a rounded fruit with a seed inside that turns a dark plummy red when ripe (hence the “plum yew” common name).

It’s a lot of fun to have the male and female plants and get the fruit. Some of the cultivars will actually give you the indication of whether it’s male or female.

They’re much more heat-tolerant than the yew we use in the Northeast—which is why we were so interested in them in our work at North Carolina State University. They can also take quite a bit of cold in the winter.

Q.  I’m crazy about crabapples, and am glad to hear you recommend them, too. Which ones in particular?

A. There’s a cultivar that I love called ‘Donald Wyman,’ and the buds emerge a kind of a pinkish color, and the flowers are white and the fruit red, and it’s a lovely shape—kind of rounded and mounding.

There’s a species form of crabapple that not everybody’s aware of that you can get in the trade, and it’s called Malus sargentii, or Sargent‘s crabapple. It’s smaller and mounding—again with the pink buds, white flowers and red fruit that is my favorite combination. [The ones in the photo above of mounded habit in Margaret’s garden are ‘Candymint,’ Sargent-type hybrid but with pink flowers.]

I love to underplant them with lots of bulbs, because you have that lower, mounding canopy that relates visually to the bulbs that flower at the same time.

They’re both relatively disease resistant, which is very important to be aware of that with crabapples, especially in areas like the Northeast, since you don’t want them to be disease reservoirs. [More on how to select crabapples.]

Q. Any other smaller trees for the home garden, besides the Sargent-style crabs?

A. There are these two other maples that I love—not natives, like our bigger sugar maples, but Asian species. They are Acer triflorum, the three-flower maple, and Acer griseum, the paperbark maple.

They’re both in the trifoliate group of maples—their leaves are divided into threes, which I know is a bad association because of poison ivy!

They have beautiful, exfoliating bark—the griseum is very red bark; on the triflorum it’s ashier, but very graceful.

The fall color on both is extraordinary—and they are very resilient, and will tolerate poor and clayey soils.

Acer pseudosieboldianum from Korea is another small maple with great fall color, by the way. [Photo above, in Margaret’s garden.]

Q. Any other one-liners about favorite woody plants?

A. I’ve never met a Cornus kousa, or kousa dogwood, that I didn’t like. [A kousa in fruit, above.]

Looking for natives? Think about tulip poplars (Liriodendron tulipifera); gray and yellow birches, our own Larix laricina, the deciduous conifer called Eastern larch or tamarack.

more about dr. kim tripp

DR. KIM TRIPP—as in Ph.D. of botany and now also a Doctor of Osteopathy—practices in Sharon, Connecticut and Great Barrington, Massachusetts, in partnership with her colleague and mentor Dr. Andrew Goldman. Learn more about osteopathy on their website. “Osteopathy starts from the relationship between structure and function,” says Kim, who you can also find on the Robin Hood Radio. “So a body is effectively a large ecosystem. If the structure, or anatomy, is not working optimally, then the physiology or biochemistry is not going to work optimally.” Physics and chemistry are both at work—just as in the garden, and all of nature. Fascinating stuff!