An unapologetic plant geek shares advice and opinions on gardening, the contrived and the natural landscape, as well as occasional topics from the other side of the gate.

September 19, 2008

Hardy Orange - Poncirus trifoliata

There are few plants left in my garden from the previous owner, but one I kept was the Poncirus trifoliata or Hardy Orange. It would have been a real bitch to try to get rid of, and this fact led to my appreciation of it. Right now it is covered in colorful fruit which are fuzzy, yellow and about the size of a ping pong ball. They have a wonderful aroma that reminds me of how Kumquats taste. I have read that you can use the fruit as a substitute for Lemon, or it can be used for marmalade. They are incredibly seedy and I think there would have to be a world-wide Lemon and marmalade shortage for me to make the effort. In spring it is covered with attractive white flowers. The stems stay green in winter as do the vicious thorns which were the main reason I did not want to attempt its removal. Birds love to build nests in it as it is virtually cat proof.


Poncirus trifoliata gets anywhere from 8 to 20' tall, prefers full to part sun, and I have never watered mine in 13 years. It is native to Korea and northern China. It is indeed a citrus plant and is often used as root stock for more popular members of the family. It is listed as hardy to zone 5b into 9. We have sold this at work occasionally, but we usually prefer the cultivar 'Flying Dragon' which has unusually twisted branches and curved thorns that look like green talons. If you are interested in seeing this plant there is a picture in a previous post here. Poncirus and Citrus are members of the Rutacea family. While doing some fact checking the inner geek in me was amazed to learn this family includes some widely divergent members including Rue (Ruta gravolens), Skimmia japonica, and two Zanthoxylums - the Tooth Ache Tree ( Z. americanum) and the Sichuan pepper (Z. simulans).

14 comments:

  1. Isn't it a fascinating plant? I don't remember how I came to plant one. Mine is about 12 feet tall which brings the question - can this sucker be pruned? I've yet to find a good answer. I would love to cut it back maybe halfway but am not sure if I would ruin it or when would be the best time to do it. Any suggestions?

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  2. Phillip,
    This is a tricky plant to prune and not just because of the thorns. Like Pyracantha, I usually prune during flowering so I can avoid branches that have flowers and thus get fruit later in the fall. If you want a drastic pruning and are willing to sacrifice the fruit for a season, do it after flowering.

    Joco,
    It is indeed photogenic and reminds me of Christmas ornaments.

    Les

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  3. Okay, believe it or not, this is a plant which I have never grown! I really like it, though, I think because my family used to vacation at a farm near West Point, Va, where the cows were (usually)kept out of the swimming pool by a hedge of them. Unfortunately we were never there when the fruit got ripe, so I never knew then how pretty it was, but I can tell you that the unripe ones make great projectiles for lobbing at brothers, cousins, and visiting "elderly" (they were actually probably in their forties...)aunts who happen to be bent over harvesting vegetables!

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  4. Those are incredible seeds and quite pretty fruit.

    Gail

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  5. Les, those are the scariest seeds I've ever seen. I guess the tree doesn't reseed itself or maybe you wouldn't like it as much as you do. I can't believe it's related to my sweet little skimmias (which apparently don't cross pollinate or whatever they're supposed to do, subject for a later post).

    Jeff, surely you don't mean the cows got into the swimming pool--though I guess I've seen them swimming in old Westerns and such . . .

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  6. It looks more like a lemon then an orange! My, what big seeds...

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  7. What strange fruits! They seem from another planet. I love your images of them.

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  8. As Crocodile Dundee would probably say, "No this is a seed".... : )

    I think I would like the fruit. I love lemons. I slice them and eat them with salt (yes I know that's bad for me) At any rate, it a pretty tree to have around. I would worry about thorns though. I have cats that climb trees.

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  9. I've never seen it before. It is beautiful with the fruit hanging from the branches. I would pick them and cover with whole cloves. I bet it would smell very Autumn.

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  10. Great for lemon juice though, I'm imagining. With a good strainer? I have two Meyer's lemons struggling in the ground here - hoping once they get settled in they'll do okay. Right now I think the winter is too tough on them, even though I protect them.

    I have a friend pruning a pyracantha today. He's miserable!

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  11. Be careful, the fruit is listed as containing an oil and a saponic glycoside which can be somewhat toxic, according to Dr. Alice B. Russell et al in "poisonous Plants of North Carolina (http://www.ces.ncsu.edu/depts/hort/consumer/poison/Poncitr.htm)

    It is considered able to cause severe stomach pain and nausea, and skin irritation from prolonged contact, but other sources suggest it has sometimes been used to make lemonade and marmelade. It is possible the marmelade is safer, since it is cooked. A link to another plant with a possibly different saonic glycoside (
    http://www.plantzafrica.com/plantklm/momordbalsam.htm)theorizes that that plant's toxicity may be neutralized by cooking, but I don't know if that would eliminate any risk from the oil or not...unless the oil evaporates.

    I would nevertheless like to grow one, and will make marmelade if it ever fruits for me here in PA!--eibren from GardenWeb

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  12. Eibren,
    Thank you for the informed warning, but rest assured I have no plans of eating it raw, in lemonade, as a marmalade or any other way.

    Les

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