American Yellowwood

American Yellowwood

Cladrastis kentukea photo credit: S. Keitch

It is dubious to make a claim that something is your favorite plant, but when someone asks me what my favorite native tree is, I can narrow it down to a few.  At the top of that short list is the American yellowwood, Cladrastis kentukea.  I have the tendency to point out a plant every five minutes and claim that it is my new favorite, so when I have a definitive answer, it is after great consideration. Without hesitation, I can say that the Yellowwood is my favorite native tree. Right now there are several large ones putting on a spectacular show at the Scott Arboretum.

Cladrastis- Leaf

Leaf of Cladrastis kentukea. photo credit: S. Keitch

The common name is self explanatory, as the vascular system produces yellow wood.  The range of the yellowwood is not a contiguous expanse as many trees of the Appalachia are, but consists of small endemic regions that are located sporadically from the southeastern United States into the Midwest.  The foliage is very handsome, with each compound leaf reaching about one foot long and consisting of leaflets that are roughly four inches each.  This is not only creates a stunning texture, but provides a nice backdrop for the graceful white inflorescences that resemble pendulous wisteria flowers.  The white flowers reach a foot in length and are typical of the pea family.  Currently they are falling all over the Terry Shane garden, creating the impression that there was a light dusting of snow overnight.  The foliage also turns a rich yellow in autumn, and the steel grey bark, much like a beech tree, carries the specie’s ornamental appeal well into the winter.

Cladrastis- Flowers

Flowering Cladrastis kentukea. photo credit:S. Keitch

Personally, I think the versatility of the yellowwood may be its strongest attribute.  It can tolerate sun or shade, acidic or alkaline soil, and even compact or saturated conditions.  However, it will grow more slowly when it has to overcome adverse conditions.  Its optimum culture would include rich, well drained soil, with rapid growth being encouraged by shade.  An interesting yet unfortunate trait of the yellowwood is its likehood of splitting apart at the crotch of the tree.  After forty years or so, unpruned trees will eventually reach a threshold of pressure at their lower crotch, where all of the major limbs come together. In a tree’s juvenile period, leads may be thinned out in order to alleviate pressure to extend its life expectancy.

Cladrastis Trunk

A view of the trunk of Cladrastis kentukea. photo credit: S. Keitch

This is such a promising tree that I would recommend it to anyone looking for an addition to their property.  In fact, everyone should plant one.  Please come to the Scott Arboretum for inspiration!  Once you are here, you will see yellowwoods all over the arboretum, in all of their glory.  Large specimens can be found in near the Wister Center, the Nason Garden, and Parrish Hall.

Sam Keitch
skeitch1@swarthmore.edu
35 Comments
  • Christine B.
    Posted at 12:20h, 20 May Reply

    I have a small one in my yard. It is rather unhappy in my climate and the new wood doesn’t ripen enough to be hardy over winter. So I have a three foot mini-tree that only sprouts from the old wood. I don’t suppose it will ever flower, either. For a mini-tree, it is lovely, with light yellow fall color and the trademark smooth gray bark.

    Christine in Alaska

  • Susan T
    Posted at 17:28h, 28 May Reply

    I live in south Louisiana, and my son is in school in Hyde Park, NY. He sent me a lovely photo, asking, “Mom, what is this tree???” Of course, I’m not familiar with Zone 5 – 6 trees that aren’t hardy in Zone 8 – 9!! But I did a little research based on his great photos, and discovered he has an American Yellowwood blooming outside his apartment! I learned something today, thanks to your site!

  • Dawn G.
    Posted at 18:04h, 08 July Reply

    I hear they only bloom well every few years. If I had more than one would they all bloom best in the same years or would each be on it’s own cycle?

  • Andrew Bunting
    Posted at 07:38h, 12 July Reply

    Each tree would be on its own cycle. It is true that they seem to bloom well every other year.

    Andrew Bunting, Curator

  • Brian Culver
    Posted at 13:29h, 29 July Reply

    Where can you buy a American Yellowwood at?

  • Andrew Bunting
    Posted at 07:45h, 02 August Reply

    We will have it available at the Scott Arboretum plant sale on September 16-18.

    http://www.scottarboretum.org/plantsale/index.html

  • Lisa Weitzman
    Posted at 16:15h, 15 August Reply

    My landscape architext suggested 1-32 of these on my property in the middle of a grove of old southern & copper beeches. I had to remove 3 beeches (I had 8 17 years ago—sadly down to 4) so these would have full sun but would be near a 200+ year old and a few younger (150-175+ yr olds) beeches. I would love to see this tree in person before I choose it. I live in Abington but grew up in Swarthmore (my Mother still lives there)….can you tell me approx where this is on the campus? Any thoughts where I may obtain this locally?

  • Lisa Weitzman
    Posted at 16:47h, 15 August Reply

    All my questions were answered in the others’ posts! I would like to purchase it prior to September….Is that possible?

  • Andrew Bunting
    Posted at 07:43h, 16 August Reply

    Lisa,

    The plants won’t be available until the sale on September 16-18 at the Arboretum.

    Andrew

  • Suzy H.
    Posted at 15:45h, 11 September Reply

    We just purchased an American Yellowwood at the Nursery. We live in Chicago, Illinois & I was wondering how this tree will do in our climate. Do you have any advise as to how best to nurture this tree ?

  • Andrew Bunting
    Posted at 07:41h, 15 September Reply

    Cladrastis kentukea is hardy to zone 4 so it should not be a problem growing it in the Chicago area.

    Andrew Bunting, Curator
    Scott Arboretum

  • Kelly Haack
    Posted at 15:33h, 21 May Reply

    I live in Eastern Washington and this tree was recommended to me by a local nursery. I loved the pictures, and loved it was unique but would grow in my area. I haven’t had the luck of the flowers blooming yet. This will be my 3rd year for the tree. It has grown well, but the foliage comes out very late compared to other trees in the area. Is this normal? Earlier this May, I had tiny leaves growing and we had a warm spell of mid 80’s weather. I was gone for the weekend and when we came back, all of the leaves were fried. New little leaves are starting to form again. Do you have any suggestions to help it along?

  • Andrew Bunting
    Posted at 07:43h, 22 May Reply

    Kelley,

    It sounds like your tree might have a vascular problem. If you have any pictures you want to share you could send them to me at abuntin1@swarthmore.edu.

    Andrew Bunting, Curator
    Scott Arboretum

  • Patricia D.
    Posted at 02:37h, 11 June Reply

    We need to know if the American Yellowwood is resistant to the toxins of the Black Walnut? We have a seedling black Walnut that has sprouted last year putting our Yellowwood within the danger zone of the Black Walnut.

    Thank you.

  • Mary Lou Surgi
    Posted at 09:34h, 21 April Reply

    I have the same question about Black Walnut toxicity. I would like to plant a Yellowood here where it is native in western North Carolina. But it would be within about 1–20 feet of the dripline of a huge old black walnut!! Please help!

  • Fran
    Posted at 12:10h, 13 July Reply

    This is my absolute favorite tree. We planted one 7 years ago in our yard and it finally flowered this year. It was beautiful. Unfortunately, we found its major crotch has split. We had an arborist in and he fixed it up with steel bracing and a dynamic strap. It was also pruned to alleviate its dense crow. It looks wonderful and we were glad to be able to save it. We live in the Southern Georgian Bay Area in Ontario Canada, and it thrives! I recommend this tree to all!

  • Susan
    Posted at 09:23h, 29 September Reply

    Is Spring or Fall planting preferable? I see references to smaller/better and also “10 years til blooming”. A skilled tree-planter has offered 1-1/2″-1-3/4″ at $200 and 6″-7″ at $1500 (ouch!). What do you think about viability at larger size?

  • Donna Matthewson
    Posted at 10:07h, 20 March Reply

    I’ve seen this tree and planted my own while living in Colorado. Now I love in Lakeland Florida, am I to far south for this wonderful tree?

  • Susan Boyer
    Posted at 03:29h, 25 June Reply

    I have a Yellowwood that I planted four years ago. The past two years it has developed numerous flower buds but they drop off before developing into flowers. The buds turn yellow at the base and then fall off. Any idea what causes this and what I can do?

  • Andrew Bunting
    Posted at 10:39h, 01 July Reply

    Where do you live? Could they be getting frosted?

    Andrew Bunting, Curator

  • Randy Umberger
    Posted at 02:43h, 19 July Reply

    where can I buy Yellowwood seedlings
    I have searched for years and cannot find these trees for less than 30 $ each
    I would like to have a hundred to raise

  • Fran Moore
    Posted at 11:40h, 10 November Reply

    I have planted three of these over the last 15 years. All beautiful specimens now. Certainly my favorite tree! Although the one in my own garden has succumbed to a splitting crotch, but I have had an Arborist put steel pins in it and strapping to stop it from getting worse. I have still noticed more cracks in the bark over the last year, and hope it makes through our cold Canadian winter. We live in Zone 5a, in Ontario.

  • Ramona Vaughn
    Posted at 02:15h, 29 May Reply

    I live in Silerton,Oregon. Implanted a yellowwood trees in 1999. It is 30 ft tall and has a spread of approximately 45 ft. It is absolutely stunning even in the years it doesn’t bloom profusely,which it is this year. Sadly I will be moving and will have to obtain another, wouldn’t be without one

  • Ramona Vaughn
    Posted at 02:16h, 29 May Reply

    I live in Silerton,Oregon. I planted a yellowwood trees in 1999. It is 30 ft tall and has a spread of approximately 45 ft. It is absolutely stunning even in the years it doesn’t bloom profusely,which it is this year. Sadly I will be moving and will have to obtain another, wouldn’t be without one

  • Doug Shorthouse
    Posted at 12:38h, 04 September Reply

    I live on the eastern end of Lake Ontario and have a 8 year old Yellowwood growing beside our deck. It fully flowered this year and is beautiful. However, the half of the tree growing out over the lawn (that gets more sun) is having much more sparse growth than the half over the deck. The leaves are smaller and more yellow and look quite dry. The trunk is now about 8 or 9 inches across and the tree is almost 20 feet high. We’re worried we’re going to lose it. Can you make any suggestions?

    • Mary Tipping
      Posted at 14:12h, 11 September Reply

      Doug — I can understand your concern about the Yellowwood. I highly recommend that consider an on-site consultation and evaluation by a ISA certified arborist in your area.

  • CS Manegold
    Posted at 06:12h, 22 September Reply

    I will be planting a really lovely 12′ yellowwood this weekend in zone 5. I understand the tree can struggle with wind. I have planned to put it within 20 feet of a mid-sized quaking aspen. I will situate it on the leeward of that tree. My other option is near the stump of an oak we needed to take down this year. That area is more protected. My question is whether we’d be safe planting in a more exposed site near the aspen. Any insight here? I love the tree. What gorgeous foliage…

    • Mary Tipping
      Posted at 10:57h, 25 September Reply

      Your best bet is a protected location; however, depending on the size of the Oak stump/roots, you may have difficulties with digging.

  • Sherrie Simmons
    Posted at 14:47h, 09 January Reply

    I would like to purchase a yellowwood, maybe 4 feet tall but am having trouble finding a site near to where I live in Western North Carolina. I am 65 years old and want to plant one that is large enough that I will get to see it bloom before I die!

  • Pat Howell
    Posted at 12:29h, 23 July Reply

    Hello. I live in Middle Tennessee, about 20 miles south of Nashville, and planted a yellowwood tree in our yard when we moved here 16 years ago. It has grown very well, is beautiful and my favorite tree. However, every August its leaves gradually turn yellow and drop off the tree; by September it is practically leafless.
    As it appears healthy in every way, I cannot understand why this is happening; any suggestions would be greatly appreciated.

    Pat Howell
    Franklin, TN

  • Victoria Wilson-Charles
    Posted at 19:58h, 20 October Reply

    I have a Cladastris lutea which has developed a number of splits in the bark out on the branches. They have curled open and become somewhat slimy in the rain here in Oregon. Any idea what might cause this?

    • Mary Tipping
      Posted at 08:21h, 25 October Reply

      Is wood exposed? If so, is it discolored, or are there any fungal structures visible?

  • Lynne M. Cimino
    Posted at 20:17h, 02 July Reply

    I have a beautiful North Carolina Yellowwood Tree in the front of my house in South Philadelphia. I live up a small residential street. My tree is planted near the curb trap. The pavement is cracking and I have a large hole near the curb trap/vent. The pavement is sinking and another cement block is rising slightly. I had the Philadelphia Water Department come out to look at my pipes. They conducted a dye test and placed a camera to observe the pipes. My pipes are OK and in good condition. Is it the tree roots since they are spreading or do I just have to remove this beautiful tree?? Please advise and who do I call?? Lynne M. Cimino

  • Barbara Rahn
    Posted at 08:18h, 29 July Reply

    We moved into our home in 1991 and have a yellowwood at the end of our driveway. We were unaware of the uniqueness of this tree as the tree flowered after 25 years of living here. It was a spectacular showing of beautiful flowers and the aroma was amazing and could be smelled from our front door which is about 150 feet from where the tree stands. We back onto a ravine and are surrounded by black walnuts. We have kentucky coffee trees, ginkgo and a beautiful mugo pine. Our yellowwood bloomed again in 2018 but has not bloomed since. Every year I am hopefull !! We live in Ontario and can have extremely cold winter temperatures could that be why it took so long to flower in the first place?

    • Mary Tipping
      Posted at 06:34h, 03 August Reply

      Hello Barbara,

      Cladrastis kentukea has a tendency to flower every 2 – 3 years. It is possible to experience a prolific period of flowering followed by a few years of little to no flowering. Cornus kousa does this as well; one year of prolific flowers followed by minimal flower production.

      Regards,

      Mary Tipping
      Scott Arboretum Curator

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